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open caster 2.0 user manual - Avalpa Digital Engineering Srl

1. 68 How to encode digital audio files with Tmped sese eee 69 How 10 capre DV Np TT 71 How to generate sSilenCG css eee eee 72 Audio and video real Case ingestion Study sees 73 Audio and video initial synchronization rrorrerrornrnornrnenernenennenennrnennener 74 Fncoding With S sed Eie 75 Play out scheduling from command ne sese sss eee 76 Re multiplexing input transport Streams see eee eee ee e e eee 82 Tol US OL US TTT 82 Appendix A Acronyms glossary and references rrnrnnrnnannrnnannrnnennennrnnenernen 84 Appendix B DVB T transmission parameters and net bitrates 68 85 Appendix C Related readings esse ese eee 86 Appendix D Mpeg2 transport stream OVvervieW rrrnannrnnannannennennennenennenennnnen 87 ADB Global Adobe Computer Modules DekTec Dell DVB Firefox Gnu Ibm Java Linux Mainconcept Mozilla PowerPc Premiere Sun Microsystems are registered Trademarks of their respective owners 4 http www avalpa com Avalpa Broadcast Server user manual Introduction Avalpa Broadcast Server Avalpa Broadcast Server is a single rack unit system featuring a collection of tools to generate process multiplex play out and broadcast MPEG 2 transport stream content Transport stream usual file suffixes are TS TP TPS TPR is a communication protocol for audio video and data which is specified in MPEG 2 ISO IEC standard 13818 1 An overview of the protoc
2. Stream Source USB Dektec DTU 245 4245087102 Port1 L PID 9 Service no service T amp Video PID novideo Audio PID noaudio TSRecorder f l m Tables Indicator HEr Time oflasterror Error Message E NIT actual current 33 PAT current E PMT for SID 0001 current Avalpa 1 sei R SDT actual current TS sync bas 0 Sync byte error 0 pat error 2 0 Continuity_count_error 0 PMT error 2 0 pD eror 0 Priority 2 Z Transport error 0 H CRC_error 0 PCR_repetition_error 0 PCR_discontinuity_indicator_efror PCR_accuracy_error 0 S PTS_error 0 CAT error 0 Priority 3 Z NT actual error 0 NIT_other_error 0 3 SI repetition error 0 SI Tables Services EPG Pid Grid TV Bandwidth TR 101 290 SI Tables Services Pid Grid Info Thu Feb 26 09 03 25 2009 Application started 0 00 Mbps L13439744 bps Info i Bitrate StreamGuru MPEG Analyzer Network Name Avalpa No CI module TS signal locked DVI StreamGuru Tr101 290 StreamXpert 3mpe ts Analyser Record View Help DVBMode 00 amp X user Gils T 100ms Gy gt W Me 2 1 ASV SDI DTU 245 9 v i Normal Hen Y PID info 7 PCR AC Snapshot Avalpa 1 PCR PID 2064 P 0 PAT 4 1 kbps 0 03 100 PS 16 NIT actual 1 37 kbps 0 01 E 17 SDT actual 1 37 kbps 0 01 E 1031 PMT 4 1 kbps 0 03 X 2064 MPE
3. will record for 3 hours 30 minutes and 10 seconds here is other time specification supported SMIL time value XXX Y h XXX Y min XXX Y s XXXms HH MM SS ms smpte HH MM SS FF The resulting recordDV avi file can be converted as explain in previous chapter into audio and video streams The next chapter will show a complete ingestion from DVD data available on the net you can replace the vob file with your DV file and execute the same steps e You can also connect DVGrab directly into ffmpeg and then directly to a playout S K dvgrab format dvl home avalpa ffmpeg ffmpeg f dv i acodec mp2 ac 2 ab 128000 ar 48000 f mp2 y live mp2 s 720x576 deinterlace r 25 aspect 4 3 f yuv4mpegpipe y home avalpa mjpegtools 1 9 0 yuvdenoise yuvdenoise home avalpa ffmpeg ffmpeg i an vcodec mpeg2video f mpeg2video b 2000k maxrate 2000k minrate 2000k bf 2 bufsize 1343488 y live mpv 72 http www avalpa com Avalpa Broadcast Server user manual How to generate silence Sometimes it is useful to generate silent audio tracks for this purpose a simple example using sox and ffmpeg is given dd if dev zero of silence raw bs 1152 count 4 sox t raw r 48000 s w c 2 silence raw silence wav ffmpeg vn f sl6le ab 128k ar 48000 ac 2 i silence wav acodec mp2 silence mp2 In this case 1152 is the number of samples of a single mpeg2 audio frame so in this way we can control how many frame
4. Interactive TV standards by Steve Morris The main specification OpenCaster refers to is ISO IEC 13818 1 Information technology Generic coding of moving pictures and associated audio information Systems As the specifications are a bit dry and don t really explain the context we suggest you to read them after you are already quite confident with the overall picture however it s quite useful to have it on your desk to check the exact meaning of every parameter used by OpenCaster that strictly follows the name used in the specification for every variable 12 http Www avalpa com Avalpa Broadcast Server user manual Avalpa Broadcast Server basic concepts and usage Let s begin with the simplest way to stream something out in the air In the next paragraphs we ll move from easy exercises to more complex ones explaining in great detail what are trying to achieve and why we are doing that way Don t forget to login as avalpa user and password avalpa after that you are ready for your first tutorial Your first transport stream goes broadcast start here A Transport Stream TS is made of packets a packet is the minimum unit that cannot be splitted has a fixed length of 188 bytes and always starts with a synch byte 0x47 Each table or elementary stream in a transport stream is identified by a 13 bit PID A demultiplexer extracts elementary streams from the transport stream in part by looking for packets ide
5. clean off DDB size update flag mount frequency carousel directory the directory to marshal in an object carousel association tag aka common tag referenced by PMTs and AITs every carousel has one modules version all the modules will have the same version you need to change this to notify to the box files are changed goes from 0 to 15 pid referenced by PMTs using this carousel carousel id referenced by PMTs using this carousel every carousel has its own it is an alternative for association tag they have the same function compress mode 0 don t compress 1 compress all 2 smart compress file with solo extension are set in an uncompressed module alone to allow use cases like quick image file update default is 2 padding on every section is padded was useful with some buggy decoder waste bandwith default off unsupported since OpenCaster 2 4 8 clean off don t delete temp file default off used for debug DDB size Use custom size for DDB payload default max 4066 sets the Update flag in the TransactionID of DSI and DII to the value given 0 or 1 mount frequency set how often insert DII DSI SGW to speed up carousel mount default is twice per carousel period Here is an example assuming ocdir1 is the directory you want to broadcast oc update sh ocdirl 0xB 0x5 2003 7 1 0 0 4066 0 2 will generate ocdir1 ts than can be muxed to all the other transport stream files the parameters passed spe
6. 0 lt S 0 S 5 1 2008 06 13 17 41 04 No section with table id x4E for more than 2 00s 0 S S 0 S 0 u a gt PIDATS 6007 N gt m PIDATS AGrid ATV APOR TR 101 290 Messages a x Trace bar ax 06 13 2008 17 34 16 Input signal detected E 06 13 2008 17 35 19 Synchronised to stream with 188 byte packets 06 13 2008 17 35 19 Lost synchronisation as ee sanas s M 4 b bi Ninfo System rate TR 101 290 Ready 188 Byte TsRate 13 270 656bps 18 1 Mode DVB ASI SDI DTU 245 at 0x01 2 REC 18 http Www avalpa com Avalpa Broadcast Server user manual something seems wrong with the PCR that s the timing information of the transport stream there are two reasons for this e we need to properly manage the loop of the video to avoid the embedded time info to go backward in time e sample ts was a result of a multiplexing without PCR correction both problems can be addressed using tsstamp and another fifo connection so here we go mkfifo mysecondfifo ts tsloop sample ts gt myfirstfifo ts amp tsstamp myfirstfifo ts 13271000 gt mysecondfifo ts amp tsrfsend myfirstfifo ts mt OFDM mC QAM16 mG 1 4 mc 2 3 mf 578 13271000 if you recall was the bit rate we are modulating L StreamXper E gt R llle Analyser Record View Help DVBMode 00 amp X short term Gls T 100ms Gy gt m 2 1 ASI SDI DTU 245 0 No decoding
7. 8 MHz FFT 8 K V PID 2064 A PID 2068 P THH BERE j1 Thu Jun 12 2008 18 04 Avalpa 1 01 00 00 00 epg event name 00 30 12 30 epg vent hame z 32 gt http www avalpa com Avalpa Broadcast Server user manual and to the analyser too StreamXpert No rec x i Analyser Record View Help i DVBMode 00 amp X shortterm Gls T 100ms GP gt B Me 2 1 ASVSDI DTU 245 0 No decoding z Video v Audio i Normal lt den PID info 9 H 0 PAT 2 9 kbps 0 02 fF 16 NIT actual 1 46 kbps 0 01 P 17 SDT actual 1 46 kbps 0 01 f T 18 HT actual 2 9 kbps 0 02 P 20 TDT 1 46 kbps 0 01 m 1031 PMT 2 9 kbps 0 02 fe 2064 MPEG 2 Video 2 3 Mbps 17 3 JJ 2068 MPEG 1 Audio 433 kbps 3 3 6 8191 Null packets 10 5 Mbps 79 3 e e T Si repetition eror Z Unreferenced PID SDT actual ener SDT other enor ElT_actual_eror EIT other eror RST enar THT eror CR Ra gt H PID TS AGrid 7 R 4 H PIDATS AGrid ATV APCR TR 101 290 Messages a x Trace bar ax 06 12 2008 14 59 22 Input signal detected 2 06 12 2008 14 59 22 Synchronised to stream with 188 byte packets N 4 p info System Ready mc hostol0 hom W Editor Photoshop 4 StreamXpert No re All green lights This is as we like it most as you can see there are no more errors because the last red light
8. A 404F7 1 A 404 7 2 A 404 753 AF 40444 A 404 5 A 40476 A 404 7 A 404 78 A 404 9 AF404 1 AF40442 A 404 3 AF 404F74 AF40445 A 40476 A 404 7 AF 404F78 A 404 9 A 404 10 AF404 41 1 A 404712 A 404 710 AF404F7 11 A 404 712 a 404 4 1 a 40442 at40443 a 404 4 a 40445 a 404 46 a 40447 a 404 48 a 404 9 a 404 10 a 404 711 36 a 404F71 a 40442 af404 43 a 404F74 a 404F75 a 404 46 aXt404F 7 a 40478 a 404F9 a 404 10 a 404 41 1 http www avalpa com Avalpa Broadcast Server user manual Every pages is made of teletext packets each packet is an unit The first packet is the header line packets and looks like this EBUTeletext stuffing the information data unit id 0x02 0x02 non subtitle 0x03 subtitles OxFF field_parity 01 which field odd or even line_offset 0x7 this is the first useful analog line to insert magazine 0x04 here we describe page 404 row 0x00 24 0x17 lines per magazine 0 is the page header page 0x04 subpage 0x0000 erase_page 0 no special request for this page newsflash 0 subtitle 0 suppress_header 0 update_indicator 1 interrupted_sequence 0 inhibit_display 0 magazine serial 1 country code 0x03 chars Avalpa TXT 10 04 2009 15 00 the header itself Packets belonging the the page will report only the magazine number 4 so this can lead to wrong pages is some pes packets are
9. B PCR AC Snapshot Avalpa 3 PCR PID 2066 0 100 200 300 400 500 600 700 800 900 ms 1000 PCR_AC PCR Interval Density Density 200 160 120 80 40 0 40 80 120 ns 160 200 0 10 20 30 40 50 60 70 80 90 100 ms NA H PIDATS AGrid 7 Messages R 4 gt H VPIDATS AGrid ATV PCR ATR 101 290 7 a x Trace bar 06 12 2008 12 46 57 Synchronised to stream with 188 byte packets F N 4 gt H info System Bit rate TR 101 290 Ready SS Te me host610 hom 188 Byte TsRate 13 270 528bps 52 6 Mode DVB ASI SDI DTU 245 at 0x01 2 REC StreamXpert No record file i Analyser Record View Help X short term amp ls Ti100ms Gy gt B Me 2 1 ASK SDI DTU 245 DVBMode 00 amp No decoding v Audio EJ 0 PAT 4 3 kbps 0 03 M 16 NIT actual 1 41 kbps 0 01 P 17 SDT actual 1 46 kbps 0 01 P 1031 PMT 4 3 kbps 0 03 P 1032 PMT 4 3 kbps 0 03 P 1033 PMT 4 3 kbps 0 03 MPEG 2 Video 2 1 Mbps 15 6 MPEG 2 Video 1 95 Mbps 14 7 MPEG 2 Video 2 4 Mbps 17 9 MPEG 1 Audio 190 kbps 1 4 MPEG 1 Audio 186 kbps 1 4 JJ 2070 MPEG 1 Audio 186 kbps 1 4 8191 Null packets 6 3 Mbps 47 4 B 8 8 8 80 80 8 8 0 B 0 A B Gy Services 3 d Avalpa 1 2 3 Mbps 17 0 9 2064 MPEG 2 Video 2 1 Mbps 15 6 J 2068 MPEG 1 Audio 190 kbps 1 4 Program
10. DTS on test h264 on test Most of audio encoders usually won t present a difficult challenge because for broadcasting usage their bit rate is constant and frame size is constant too so you will have only to get some parameters from the encoders configuration and match them with Avalpa Broadcast Server s parameters Video Elementary Stream input however is a far more complex subject For mpeg2 video the server makes available an analyser tool called mpeg2vbv Video Buffer Verifier that will report problem with the video input doing a decoder buffer simulation H264 analyzer will be available soon Video bitrate can be both Variabile Bit Rate VBR or Constant Bit Rate e CBR however in a digital video broadcasting architecture VBR makes sense gt only if multiplexers and encoders talk to each other and realize a statistical multiplexing otherwise using a VBR encoding without a statistical multiplexing would be just a waste of bandwidth As far as we know there is not a standard about statistical multiplexing and every vendor has its own lock in proprietary protocol between encoders also statistical multiplexing is valuable only on some context and requirement Working with pre encoded files the choice of CBR is a must especially for VOD services but also for scheduled services with small number of live programes To get your video encoded there are many possibilities we describe some of the most common An open source encoder
11. HbbTv signalling hbbtv hbbtv dsmcc An example of HbbTv signalling linking a http application is also available and example is similar to MHP MHEGS5 but no DSMCC let s have a look the the ait table parameters reported into ths AIT to signalize a broadband application appli_name application Portail application name appli_root http 192 168 1 1 portail URL base of transport protocol descriptor appli_path index html initial_path bytes of simple application descriptor organisationId_1 10 this is a demo value dvb org should assign an unique value applicationId_1 1001 this is a demo value This number corresponds to a trusted application applicationId_2 1002 ait application information section application type 0x0010 common descriptor loop external application authorisation descriptor application identifiers organisationId 1 applicationId 1 organisationId_1 applicationId_2 application priority 5 1 l application loop L application_loop_item organisation id organisationId 1 application id applicationId 1 application control code 1 AUTOSTART application descriptors loop transport protocol descriptor protocol id 0x0003 URL base appli root URL extensions transport protocol label 3 1 application_descriptor application_profile 0x0000 0x0000 basic profile 0x0001 download feature 0x0002 PVR feature 0x0004 RTSP feature version_major 1
12. corresponding to version 1 1 1 version_minor 1 version_micro 1 the service_bound_flag 1 the application is expected to die on service change visibility 3 the applications is visible to the user application_priority 1 transport_protocol_labels 3 If more than one protocol is signalled then each protocol is an alternative delivery mechanism The ordering indicates the broadcaster s view of which transport connection will provide the best user experience first is best application name descriptor application name appli name ISO 639 language code fra simple_application_location_descriptor initial_path_bytes appli_path OCtutorail17 shows an example where the HbbTV application is sent over DSMCC 46 http www avalpa com Avalpa Broadcast Server user manual Update an object carousel with running applications mhp A usefull feature of DSMCC is that a running application can monitor a file on the DSMCC and be notified if the file is changed after it was transmitted and received at least once The basic notion is that every file of the DSMCC is in a module and every module is ina section SO we need to update the section version as for all the PSI tables If the carousel was generated with version 5 as in the previous chapter try to edit the text from ocdir1 change_text file in our example we changed from Write something to Write something Update You can execute
13. minrate bitrate in kbps that s depend on you pay attention some version of ffmpeg use kbps as input others bps so you need to add zeros bf number of b frame for gop bufsize vbv buffersize the version of ffmpeg used while writing this document is expecting the buffer size in bit so it s vbv_buffer_size 1024 16 1835008 however in many encoders vbv for mpeg 2 video codec is often expressed in 16Kbits unit Be sure to check the output with esvideoinfo and vbv as explained in Analysing video files when you are done with encoding you will need to do encapsulation ffmpeg actually has an option to output elementary stream encapsulated into transport stream but as of this writing it s totally broken You can encapsulate the video elementary stream into program stream with esvideo2pes like this esvideompeg2pes video mp2 gt video pes You can analyse the output with pesinfo video pes You can encapsulate the video into a ts like in this example pesvideo2ts 2064 25 112 5270000 0 video pes gt video ts 2064 is the video pid 25 is the frame per second 112 half vbv on many decoders 224 is fine others have half of it because DVD uses half and sometimes it happens also DVB decoder get the same limitation 5270000 is the ts bit rate it has to be bigger than the video bit rate automatic minimum guess is still not available on the software 15 more should be fine the tool will adjust the pts and the dts to take into account
14. 3810983 picture 129 start header temporal reference 9 picture coding type B Frame vbv delay 24130 frame size 22844 e Some of these parameters are relevant because they will be useful for multiplexing so 65 http www avalpa com Avalpa Broadcast Server user manual let s have a short description of relevant parameters in the next chapter In MPEG 2 three picture types are defined The picture type defines which prediction modes may be used to code each block Intra pictures l pictures are coded without reference to other pictures Moderate compression is achieved by reducing spatial redundancy but not temporal redundancy They can be used periodically to provide access points in the bitstream where decoding can begin Predictive pictures P pictures can use the previous I or P picture for motion compensation and may be used as a reference for further prediction Each block in a P picture can either be predicted or intra coded By reducing spatial and temporal redundancy P pictures offer increased compression compared to I pictures Bidirectionally predictive pictures B pictures can use the previous and next l or P pictures for motion compensation and offer the highest degree of compression Each block in a B picture can be forward backward or bidirectionally predicted or intra coded To enable backward prediction from a future frame the encoder reorders the pictures from natural display o
15. b 2300000 firstvideo ts b 188000 firstaudio ts b 2300000 secondvideo ts b 188000 secondaudio ts b 2300000 thirdvideo ts b 188000 thirdaudio ts b 3008 mptspat ts b 3008 mptspmtl ts b 3008 mptspmt2 ts b 3008 mptspmt3 ts b 1400 mptsnit ts b 1500 mptssdt ts b 5792069 null ts gt myfirstfifo ts amp tsrfsend myfirstfifo ts mt OFDM mC QAM16 mG 1 4 mc 2 3 mf 578 The clip files are very short and with a very small bit rate many decoders can have problems decoding channel 2 and channel 3 channel 1 should play smooth on all decoders this can also be a test on your mpeg2 decoder recovery capabilities A problem arises because the videos are looped and so from the point of view of the decoder the PCR goes back in time after the end of the first loop when we come back playing the same ts loop a second time you can try to fix PCR using tsstamp like here tscbrmuxer b 2300000 firstvideo ts b 188000 firstaudio ts b 2300000 secondvideo ts b 188000 secondvideo ts b 2300000 thirdvideo ts b 188000 thirdaudio ts b 3008 mptspat ts b 3008 mptspmtl ts b 3008 mptspmt2 ts b 3008 mptspmt3 ts b 1400 mptsnit ts b 1500 mptssdt ts b 5792069 null ts gt myfirstfifo ts amp tsstamp myfirstfifo ts 13271000 gt mysecondfifo ts amp tsrfsend mysecondfifo ts mt OFDM mC QAM16 mG 1 4 mc 2 3 mf 578 Please note that input files are generated by OpenCaster itself check re multiplexing section for multiplex inputs from other systems Some screenshots from the dec
16. crypted ts the input transport stream will be crypt using control words from file cw those are 8 bytes twice odd and even keys it is a perfect match for a biss cam The PSI signalling required is carried out in the pmt pmt program map section program number avalpal service id PCR PID 2064 program info descriptor loop stream loop stream loop item stream type 2 mpeg2 video stream type elementary_PID 2064 element info descriptor loop ca descriptor CA system ID 0x2600 CA PLD Ox1FFF 1 stream_loop_item stream_type 4 mpeg2 audio stream type elementary_PID 2068 element info descriptor loop ca descriptor CA system ID 0x2600 CA PLD Ox1FFF 59 http www avalpa com Avalpa Broadcast Server user manual let s try some output run once only bissconfig py tscrypt keys cw firstvideo ts gt firstvideocrypted ts tscrypt keys cw firstaudio ts gt firstaudiocrypted ts mkfifo myfirstfifo ts mkfifo mysecondfifo ts always running tscbrmuxer b 2300000 firstvideocrypted ts b 188000 firstaudiocrypted ts b 3008 firstpat ts b 3008 firstpmt ts b 1500 firstsdt ts b 1400 firstnit ts b 10774084 null ts gt myfirstfifo ts amp tsstamp myfirstfifo ts 13271000 gt mysecondfifo ts amp tsrfsend mysecondfifo ts mt OFDM mC QAM16 mG 1 4 mc 2 3 mf 578 The control word used is 0x00 0x00 0x00 0x00 0x01 0x02 0x03 0x6 This won t be enough to support any ava
17. descriptor loop stream loop stream loop item stream type 2 mpeg2 video stream type 25 http www avalpa com Avalpa Broadcast Server user manual elementary PID 2064 element_info_descriptor_loop stream loop item stream type 3 mpeg2 audio stream type elementary PID 2068 element info descriptor loop l version_number 1 you need to change the table number every time you edit so the decoder will compare its version with the new one and update the table section_number 0 last section number 0 firstconfig py ends with system commands invoking sec2ts so they directly generates ts files without the need to execute manually sec2ts so execute them to generate the psi ts files 26 http www avalpa com Avalpa Broadcast Server user manual Tool dvbsnoop start here dvbsnoop http dvbsnoop sourceforge net is a very useful software to analyse transport stream and it is provided in Avalpa Broadcast Server You can use it to check most the signalling in DVB networks and also Avalpa Broadcast Server own output To parse PAT from a transport stream file dvbsnoop tsraw s ts tssubdecode if sample ts N 2 0 Dvbsnoop will show you information about the PAT PID 0x0000 assigned for ISO 13818 1 Program Association Table PAT Guess table from table id PAT decoding Table ID 0x00 Program Association Table PAT section syn
18. first frame transmission delay En ie To improve the quality and the compression of the video is suggested to use yuvdenoise tool as shown below ffmpeg i input ext an s 720x576 deinterlace r 25 aspect 4 3 f yuv4mpegpipe yuvdenoise ffmpeg i an vcodec mpeg2video f mpeg2video b 2000k maxrate 2000k minrate 2000k bf 2 bufsize 1343488 video mp2 69 http www avalpa com Avalpa Broadcast Server user manual How to encode digital audio files with ffmpeg Another example with ffmpeg ffmpeg i input mpg ac 2 vn acodec mp2 f mp2 ab 128000 ar 48000 audio mp2 i input file ac 2 stereo vn no video acodec mpeg2 audio layer 2 f output format mpeg2 audio ab audio bit rate in bps ar is the audio sample rate You can analyze the output with esaudioinfo audio mp2 You can encapsulate the audio into ps with esaudio2pes like this esaudio2pes audio mp2 1152 48000 768 1 3600 gt audio pes 48000 sample rate should be known or can be learn with esaudioinfo a pts_step is 1152 sample_rate 90000 1152 is fixed for mpeg2 layer 2 so for 48khz comes 2160 1152 audio frame size you can read it with esaudioinfo it s in bytes NB this 1152 is by chance 1152 as the number of samples 3600 first pts this an important value for audio video synchronization read more below You can analyse the output with pesinfo audio pes You can encapsulate the audio into a ts with pesaudio2ts 2068 1152 48000
19. formula has rounds 5737783 461583bps drop no time code 00 00 04 pictures 18 closed no broken no frame size 20490 Postion 3525284 picture 119 start header temporal reference 2 picture coding type I Frame vbv delay 22414 frame size 78958 Postion 3604242 picture 120 start header temporal reference 0 picture coding type B Frame vbv delay 16539 frame size 17697 Postion 3621939 picture 121 start header temporal reference 1 picture coding type B Frame vbv delay 18015 frame size 18223 Postion 3640162 picture 122 start header temporal reference 5 picture coding type P Frame vbv delay 19428 frame size 30385 Postion 3670547 picture 123 start header temporal reference 3 picture coding type B Frame vbv delay 19382 frame size 18138 Postion 3688685 picture 124 start header temporal reference 4 picture coding type B Frame vbv delay 20806 frame size 23426 Postion 3712111 picture 125 start header temporal reference 8 picture coding type P Frame vbv delay 21595 frame size 29984 Postion 3742095 picture 126 start header temporal reference 6 picture coding type B Frame vbv delay 21597 frame size 17189 Postion 3759284 picture 127 start header temporal reference 7 picture coding type B Frame vbv delay 23134 frame size 20719 Postion 3780003 picture 128 start header temporal reference 11 picture coding type P Frame vbv delay 24248 frame size 30980 Postion
20. information looks odd We will fix them later in the mean time notice that the decoder is so smart to remind us of audio and video PIDs they will come handy soon 20 http www avalpa com Avalpa Broadcast Server user manual Multiplexing a Single Program Transport Stream from local files first file mux To broadcast a transport stream from audio and video frames you need to encode audio and video We will discuss later how to encode audio and video because it s a more advanced topic for now let s focus on multiplexing The mandatory standard for free view requires the following signalling tables PAT PMT SDT and NIT for a DVB stream Now that you got all the streams from the sample tutorial you need to mux them together before output them tscbrmuxer is the tool for this task tscbrmuxer gets as input a ts file and its own bitrate for example tscbrmuxer b 2300000 firstvideo ts b 188000 firstaudio ts b 3008 firstpat ts b 3008 firstpmt ts b 1500 firstsdt ts b 1400 firstnit ts gt muxed ts N B you need to stop tscbrmuxer with a signal CTRL C or it will go on filling your hard disk that s because input files are looped and muxed ts is not a fifo The resulting muxed ts will have a total bit rate sum up of the the bit rate of all the ts input files that is 2496916 bit per second The bit rate of the video stream and of the audio stream comes from the encoder settings so for now just take them as reported for the ot
21. library is available inside libavcodec from ffmpeg you will be able to encode CBR video elementary stream as described in the chapters below without problem check later chapters for details The reference encoders are also available from mpeg web site but it will probably be more cpu hungry and less effective other software decoders are available both binary open source licensed and or free MainConcept licenses software encoders with a CBR TS VBV compliant Video d ES for a good price as standalone solution also on Linux workstations or it is available as a plug in for Adobe Premiere and many other Non Linear Editing NLE softwares even Adobe Premier Elements has a high quality MPEG2 video encoder option A free trial download from their web site is also available with the only limitation of a watermark Pay attention however GUIs are not always clear on how to generate a CBR video It is worthless to say that any professional broadcasting industrial encoder hardware will be also suitable then some inexpensive pc hardware has been also reported to work good enough too if configured properly with up to date firmware 63 http www avalpa com Avalpa Broadcast Server user manual Anyway in the following pages we will present examples with ffmpeg because it is installed and it has also a quite wide range of supported input formats making the tutorials easier ko Please note the current ffmpeg version 0 6 1 has also a basic transport st
22. lost anyway a typical teletext text line looks like EBUTeletext data unit id 0x02 field parity 01 line offset 0x8 magazine 0x04 row 0x01 the first teletext page row line just after the header chars A_404 1 A 404 1 ee 37 http www avalpa com Avalpa Broadcast Server user manual DSMCC carousels and data casting DSMCC is one of the standard to broadcast files over transport streams The most common uses are to broadcast decoder software upgrades DVB SSU and or applications for interactive television like MHP OCAP tru2way MHEGD To implement carousels into OpenCaster architecture a directory has to be marshalled into a transport stream and the transport stream file need to be recreated every time the directory change like PSI tables If the carousel is created properly you will just need to add it to all the other transport streams into your multiplexing loop To add more carousels you will need just to add them like any other transport stream file to the multiplexing DVB SSU ssu The tutorial shows how to set up a DVB SSU update with OpenCaster Many parameters regarding the client configuration are needed to be inserted so it s not expected to work out of the box for any decoder it s just a skeleton useful for real use cases Contact info avalpa com for more details To signal DVB SSU you need to add a linkage descriptor to NIT have a look to ssu data generation py nit net
23. questions or ordering info Use cases some examples Avalpa Broadcast Server can transmit standalone directly over a local residential hotel television DVB network or integrated into a broadcaster DVB headend and comes useful in many ways 5 http www avalpa com Avalpa Broadcast Server user manual As a data broadcasting headend equipment for signalling table generation for example for LCN numbering generation electronic program guide EPG server data carousel MHP HbbTV Ginga and MHEG5 DSMCC server teletext and firmware upgrade OTA DVB SSU server multiplexed with other services As a standalone single box for scheduled pre compressed Video or Video On Demand digital television services with or without interactive support For vod service can manipulate pmt and or support CSA As a developer tool for a software house and laboratories QA and R amp D involved in digital television products Avalpa Broadcast Server can prototype advanced services directly on developers STB in the very same conditions of a real television environment and pursue certifications like MHP or MHEG5 or test OTA Many others simpler scenarios are possible like ASI to IP or IP to ASI converter or IP to DVB T C S modulator IP to IP multiplexer DVB T C S to IP IRD and so on in these use cases alone Avalpa Broadcast Server is usually an overkill compared to dedicated hardware soltutions unless you don t need both playout functions and
24. save the file F2 exit F10 and enter the following command firstsdt py 23 http www avalpa com Avalpa Broadcast Server user manual this command will generate a new firstsdt sec while sec2ts 17 lt firstsdt sec gt firstsdt ts will generate a new firstsdt ts What will happen to the old one if you the old firstsdt ts was being multiplexed the tscbrmuxer will get the new firstsdt ts as soon as the previous one was sent for the last time So get back to Multiplexing a Single Program Transport Stream set up replace firstsdt ts while the processes are running and rescan the service on the box As you have probably noticed firstsdt py has a complex structure that s because it maps 1 1 the original specifications and allows to use all of its signalling If you look at ISO IEC 13818 1 and EN 300 468 you will find the description of every single table and field OpenCaster implements the most important of them Have a look at firstconfig py for a complete example of signalling a single python script describes all of the signalling tables you are using you can split it in more files but a single file is probably easier to edit until you don t need to manage a very complex setup Take your time to understand it properly and compare it with the specifications of the single tables Shared values avalpa_transport_stream_id 1 demo value an official value should be demanded to dvb org avalpa_orig
25. the example as in the previous chapter and after you change the file content you will just need to re run oc update sh with the new version oc update sh ocdirl OxB 6 2003 1 2 0 0 4066 0 2 when the multiplexing is running and wait a few moments here how it looks after update Write something Update hi this is the open caster manual 1 2 3 47 http www avalpa com Avalpa Broadcast Server user manual An interesting features of Linux kernel since 2 6 13 is the capability to notify filesystem changes to the application so it is pretty easy to setup a bash script for auto update using inotify tools like this VER 1 while inotifywait rq e close write ocdirl do let VER 1 let VER amp 15 DATE date echo DATE updating ocdirl ts filesystem to ver VER oc update sh ocdirl OxB VER 2003 1 2 0 0 4066 0 2 done 48 http www avalpa com Avalpa Broadcast Server user manual Signalling Stream Events mhp streamevents Have you ever asked how can you synchronize a running application to a video program on going How can you send a signal to an interactive application at an exact point in time when that event is really happening on the video stream The answer is Stream Event do it now This advanced topic chapter regards exactly how to signal interactive applications and Stream Event management Stream events are signals sent on a particular PID to the interactive application and they are actually
26. to press the app button on the remote control 4 the user selects an application 5 the decoder loads the DSMCC carousel referenced by the application descriptor or connect to the remote http server 6 the decoder executes the application So let s have a look at mhpconfig py on how to active this first of all the PMT for the required referencing of AIT and DSMCC streams looks like this Program Map Table ISO IEC 13818 1 2 4 4 8 this is PMT with DSMCC and AIT descriptor for MHP interactive applications pmt program_map_section program_number avalpal_service_id PCR PID 2064 program info descriptor loop stream loop stream loop item stream type 2 mpeg2 video stream type elementary_PID 2064 element_info_descriptor_loop stream_loop_item stream_type 3 mpeg2 audio stream type elementary PID 2068 element_info_descriptor_loop stream_loop_item stream_type 5 AIT stream type elementary_PID 2001 element_info_descriptor_loop application_signalling_descriptor application_type 1 1 DVB J application 2 DVB HTML 42 http www avalpa com Avalpa Broadcast Server user manual AIT version 1 current ait version stream_loop_item stream_type 11 DSMCC stream type elementary_PID 2003 element_info_descriptor_loop a number of descriptors specifying DSMCC properites association_tag_descriptor association_tag 0xB this associati
27. v Video Audio Normal Hon w iPID info 7 Indicator Erors Time of Last Enor Eror Message gf 0 PAT 2 9 kbps 0 02 ff 16 NIT actual 1 46 kbps 0 01 Priority 1 3 17 SDT actual 1 43 kbps 0 01 TS_sync_oss 0 H 1031 PMT 2 9 kbps 0 02 Sync byte enor 0 m 2064 MPEG 2 Video 2 3 Mbps 17 3 PAT emor 2 0 JJ 2068 MPEG 1 Audio 187 kbps 1 4 Continuy count eror 0 4 8191 Null packets 10 8 Mbps 81 2 PMTeror 2 7 ID eror 0 Priority 2 amp Trensport ener 0 CRC eror 0 PCR repetition eror 0 PCR discontinuity_indicatoreror 0 PCR accuracy eror 0 CAT eror 0 Priority 3 NT actual eror 0 NIT other enor 0 Slrepettion eror 4 2008 06 13 17 42 57 No table with table id 0x70 for more than 30 00s TDT_repetition_rule Unreferenced PID 0 SDT actual enor 0 SDT other eror 0 EIT actual eror 3 2008 06 13 17 42 57 No section with table id Ox4E for more than 2 00s EIT other enor 0 RST ener 0 6 TDT eror 1 2008 06 13 17 42 57 No section with table id 0x70 for more than 30 00s M 4 p PIDATS AGrid Na H PIDATS AGrid ATV APCR TR 101 290 Messages A x Trace bar ax 06 13 2008 17 34 16 Input signal detected a 06 13 2008 17 35 19 Synchronised to stream with 188 byte packets 06 13 2008 17 35 19 Lost synchronisation ll bell HA Ninfo System Bit rate TR 101 2 Ready 188 Byte TsRate 13 270 528bps 18 8 Mode DVB ASI SDI DT
28. 1 lt PMT PID 1031 PCR PID 2064 Provider Avalpa 2 7 Avalpa 2 2 1 Mbps 16 1 2065 MPEG 2 Video 1 95 Mbps 14 7 JJ 2069 MPEG 1 Audio 186 kbps 1 4 lt Program 2 PMT PID 1032 PCR PID 2065 Provider Avalpa TY Avalpa 3 2 6 Mbps 19 3 9 2066 MPEG 2 Video 2 4 Mbps 17 9 JJ 2070 MPEG 1 Audio 186 kbps 1 4 Program 3 PMT PID 1033 fe PCR PID 2066 Provider Avalpa 5 Tables Ra gt H VPIDATS AGrid ATV APCRATR 101 2907 a x Trace bar 06 12 2008 12 46 57 Synchronised to stream with 188 byte packets N 4 gt H info System Bit rate TR 101 290 ME hosto10 hom U Edit Photoshop Avalpa Broadcast Server user manual BISS E and CSA output support csa Avalpa Broadcast Server can scramble the transport stream using CSA and support BISS E mode 1 Tscrypt will scramble your transport stream however it requires libdvbcsa provided by third parties and not installed on the server by default To install the software proceed as follow mkdir libdvbcsa cd libdvbcsa svn co svn svn videolan org libdvbcsa cd libdvbcsa trunk autoconf configure make su insert root password default is Avalpa make install exit cd home OpenCaster software tools tscrypt make su insert root password default is Avalpa make install exit Now you are ready to use tscrypt the basic usage is tscrypt input ts file cw gt
29. 76290 25 047778 ms indices delta is 41548 bytes 25 568000 ms pcr accuracy is 0 0005202222 instant ts bit rate is 13269999 5564033184 The first value is the pid number of the pcr video stream The second value is the pcr value itself The third value is the pcr difference from the previous pcr value and in brackets there is the time passed counting the pcr ticks The fourth value is the difference in bytes from the pcr position into the file and in brackets there is the time passed with the guessed bitrate on input The fifth value is the accuracy of the predicted pcr The last value is the actual bit rate measure between pcr ticks and ts bytes If the transport stream brings PCR information the tool will be able to do the computations otherwise the bit rate information need to be known out of band 28 http www avalpa com Avalpa Broadcast Server user manual IP network tools start here OpenCaster 2 0 for the first time featured some tools to send a transport stream over an IP network and their usage is very simple to exploit As in every real word problem there are some issues you should be concerned of Let s see an example tstcpreceive 7001 gt received ts Binding the socket This command will start a process waiting for an incoming connection on port 7001 that can be made from another pc tstcpsend sample ts 192 168 1 2 7001 3000000 Where the parameters are the transport stream to send the destination
30. 768 1 0 audio pes gt audio ts 2068 is the pid number 1152 is the number of sampler per frame 48000 is the sample rate 768 is the es frame size 1 disable audio description header 0 the audio won t be on loop again this is for future usage constant bit rate To calculate the output bit rate steps are 1 second is 90000 pts ticks sample rate is 48000 hz 1 frame is 1152 samples so 70 http www avalpa com Avalpa Broadcast Server user manual 90000 1152 48000 2160 is how many ticks is a frame an audio pes frame is made for example of 384 byte so this means 384 184 2 08 TS packets with padding on third packet so 3 packets 188 bytes 564 bytes 4512 bit per pes audio frame 4512 bit for 2160 ticks you convert with bps it comes 4512 90000 2160 188000 bps When bit rate is not round you should consider using the floor integer find out that the TS bit rate is the same Check OpenCaster README for EN Beware of padding if you check the math for audio bit rate at 160kbps you will smarter mpeg2 audio bit rates 71 http www avalpa com Avalpa Broadcast Server user manual How to capture DV input This chapter assumes you connected a digital video camera or a digital video player to the firewire of the server To record the DV you have to use the command dvgrab recorded dv But this way it will never stop recording so to stop it you can use ctrl c or use a duration time dvgrab d 3 30 10 recorded dv
31. Avalpa Broadcast Server user manual Avalpa Broadcast Server User Manual document release 3 0 suited for OpenCaster version 3 1 date 18 04 11 AALP LAOA ET 1 http www avalpa com Avalpa Broadcast Server user manual Dedicated to Anna Asli amp Renzo baossnet OG lepidaspa 2 http www avalpa com Thanks to Avalpa Broadcast Server user manual Table of contents General Index Avalpa Broadcast Server User Manual eee 1 Table OF ele RT ETT 3 TREGOR T 302020 E A aa aay aon SN 5 Avelpe Broadeast Server SS 5 Avalpa Digital Engineering sese eee eee eee 5 Use cases Some exa DIGRASKAR RESORT dad EE 5 Demonstration sesime arenei E e E ine MUL aAA a Bs EE 6 OPE ASE CK paseon Are AE a a a a a aa a a anaa a 6 Copyright and va eee e aaa A a a aa d ENG 7 Op nGaster the SOM WAC vc 05s conse oan IE EAE EE eaea eo 7 Avalpa Broadcast Server the manual eee ee eee eee 7 First TS ETH Se 8 Eon noe SERT 8 Setting Up a fixed IP address oeeie reisiin AAKE aa EET r RNa 8 Configure multicast FOULING Kc y sis nn ses eee 8 Scope of the user manual and intended audience rerrnrnonernernrnernrnvnenenenennnr 10 How to read the manual sese eee 10 Interesting and basic TEACINGS ceccsecsecsecececcececeeeeececesseseseeseeeseeees 11 Avalpa Broadcast Server basic concepts and USAGE sccceceeececeeeeeeeeeeneenes 12 Your first transport stream goes broadcast 12 Multiplexin
32. G 2 Video 2 6 Mbps 19 8 JJ 2068 MPEG 1 Audio 187 kbps 1 4 8191 Null packets 10 4 Mbps 78 7 No decoding v Video E RHH su 0 100 200 300 400 500 600 700 800 900 1000 ms PCR_AC PCR Interval Density Density 200 160 120 80 40 0 40 80 120 160 200 0 10 20 30 40 50 60 70 80 90 100 ns ms RE p PIDATS AGrid 7 R gt H PIDATS AGrid ATV PCR ATR 101 290 7 Messages a x Trace bar ax 02 26 2009 08 45 11 input signal detected 02 26 2009 08 45 11 Synchronised to stream with 188 byte packets M 4 gt H info System Ready GG creat S GpenCasterUserM StreamXpert PCR analysis 80 http www avalpa com Avalpa Broadcast Server user manual E Rohde amp Schwarz D M MPEG 2 Monitoring System 4 62 0 4 File View Setup Scheduler Help Sel Eos Advanced PCR Analysis Input 1 TS ASI Configuration DVB Config DVB 2 Rohde amp Schwarz DVM PCR Analysis PTS Analysis Butter Analysis Buffer Model nfo Input 1 TS ASI Service 1 Avalpa 1 PCR PID 2064 PCR o 0x000AD28F1 0x0043 00 02 06 091213 4 PCR Jitter Pos Pk 55ns Neg Pk 22ns Limit 500 ns So TU Ts AD 1 EG parsi PAT PID 0 9 PMT i Service 1 PID 1031 G NIT PID 16 HE SDT PID 17 3 Service 1 Avalpa 1 M video MPEG2 PID 2064 dg Audio MPEG1 PID 2068 AIT PID 2001 Kj Data MHP Object Carou
33. U 245 at 0x01 2 REC 1 T 7 7 BS SPE Orno pE ss StreamXpert No re TT ETT ditor P a T ERT 1743 As you can see PCR is better now and an error can occur at maximum at the end of the loop some red lights about Electronic Program Guide are reported however many decoder will still have problem to decode this stream after the first loop because a transport stream needs to respect not only transport constraints but also many constraints at elementary stream level on how the end and the start of the streams actually chain together This kind of constraints are related to the inner elementary streams themselves and are not shown in this analyser that is focused on the transport stream level We will 19 http www avalpa com Avalpa Broadcast Server user manual address them later on 18 AS we want to give away tutorial examples for OpenCaster without huge video file downloads we have prepared some loop able transport streams for the next chapters but don t forget that usually a transport stream is not seamless loop able on any decoder without some more processing of its elementary streams advanced chapters will show how to deal with this issue Pressing the info button on the decoder we figure out what were the last complains of the analyser tool 16 54 21 Composite2 Digital 578 000 MH 8 MHz EET 8 K 064 PID 068 P PID 2064 1970 02 38 the Electronic Program Guide info are missing and time
34. acket per second so the result is the command line states that every 15 TXT packet a new PES packet will be generated and every PES packet matches a video field pesdata2ts txtpage pes 1978 gt txt ts amp Pesdata2ts the second tool we are using will just encapsulate PES packets in TS packet with the given PID in this case is 1978 To know the bit rate for the teletext transport stream math is easy after starting to execute txt2pes it will report about PES packet size for example pes packet size without 6 byte header is 1144 this means 1144 6 1150 bytes per packet 1150 184 TS packet payload 7 TS packet every PES packet 7 188 8 gt 10528 per PES if PES goes at 3600 means 10528 90000 3600 gt 263200 bps For the previous example we have 730 6 gt 736 184 gt 4 188 8 gt 6016 90000 1800 gt 300800 bps So the final processes layout assuming the teletext packets are already generated and 34 http www avalpa com Avalpa Broadcast Server user manual stored in pages txt file is txt2pes pages txt 15 3600 1800 gt txtpage pes amp pesdata2ts txtpage pes 1978 gt txt ts amp tscbrmuxer b 2300000 firstvideo ts b 188000 firstaudio ts b 28008 pat ts b 28008 txtpmt ts b 26500 sdt ts b 1400 nit ts b 300800 txt ts b 10398284 null ts gt muxed ts amp tsstamp muxed ts 13271000 gt stamped ts amp tsrfsend stamped ts mt OFDM mC QAM16 mG 1 4 mc 2 3 mf 578 The tuto
35. adcaster and software development companies who are looking for a reliable and accountable baseline for digital television advanced services We really like to share most of this software as we believe for a digital television market to grow there s more need of different services then technologies so with a shared common proven set of basic tools we can all focus resources and propose new contents and services on top of an openly available technology Then the final goal for this manual is to show clearly that managing this digital television stuff is not that easy and that you the user should trust Avalpa if you think you should focus on your core business and leave to professionals to deal with the gory details of the technology Who s better then Avalpa people with regard to skills commitment and willingness to make win win solutions with customers How to read the manual This manual is provided AS IS and nothing is guaranteed We have written this stuff in good faith and we believe there are not a lot of mistakes If it happens you to catch one please report to opencaster avalpa com so we can fix it for you and for you mates in this crazy adventure on digital television revolution Wouldn t you like that other people would make the same choice Right It is strongly suggested to don t skip any chapters of Avalpa Broadcast basic concepts and usage in the manual because we assume at every following chapter that the reader is co
36. amp tsstamp myfirstfifo ts 2496916 gt mysecondfifo ts amp tsudpsend mysecondfifo ts 224 0 1 2 7001 2496916 Now you could try to tune this program on the decoder as for the sample ts the outcome should be the same audio video If you are broadcasting on an IP network any modern pc with VLC will be able to display the stream with an input like udp 224 0 1 2 7001 most of the IPTV set top box should also easily manage it If you want to record your output you can use the tool tsdoubleoutput mkfifo myfirstfifo ts mkfifo mysecondfifo ts mkfifo mythirdfifo ts touch outputcopy ts tscbrmuxer b 2300000 firstvideo ts b 188000 firstaudio ts b 3008 firstpat ts b 3008 firstpmt ts b 1500 firstsdt ts b 1400 firstnit ts gt myfirstfifo ts amp tsstamp myfirstfifo ts 2496916 gt mysecondfifo ts amp tsdoubleoutput mysecondfifo ts outputcopy ts gt mythirdfifo ts amp tsudpsend mythirdfifo ts 224 0 1 2 7001 2496916 Pay attention outputcopy ts file will grown and fill your hard disk However we will see that you often want to check your output when you are trying new set ups So it is very useful 22 http www avalpa com Avalpa Broadcast Server user manual Generating PSI SI basic tables psi generation Let s change our transport stream for example we want to change the service name from Avalpa 1 to OpenCaster 1 The name of the service is in the SDT table so we will need to generate a new sdt ts sdt ts is gener
37. ast_segment_section_number 1 ec To add EPG to your set up you will need to add the firsteit ts to your muxing and it would be wise also to signal a time info That s what tstdt tool is for tstdt is a tool that set the time of the service this is just a hint for the decoders user clock and doesn t affect any low level buffer synchronization issue the time is read from the pc clock The usage is very simple tstdt inputs ts gt output ts The input ts needs to already have stub tdt packets inserted at multiplexing time so the tool will replace them with packets at the current time Pay attention that if you are processing the transport stream faster than real time l e with a rate higher then the own bit rate you are going to write into the hard disk a tdt time information quite meaningless mkfifo fifomuxed ts mkfifo fifotdt ts mkfifo fifotsstamp ts tscbrmuxer b 2300000 firstvideo ts b 188000 firstaudio ts b 3008 firstpat ts b 3008 firstpmt ts b 1500 firstsdt ts b 1400 firstnit ts b 2000 firsteit ts b 2000 firsttdt ts b 10770084 null ts gt fifomuxed ts amp tstdt fifomuxed ts gt fifotdt ts amp tsstamp fifotdt ts 13271000 gt fifotsstamp ts amp tsrfsend fifotsstamp ts mt OFDM mC QAM16 mG 1 4 mc 2 3 mf 578 Let s have a look at the decoder informations 31 http www avalpa com Avalpa Broadcast Server user manual epg event name this is an epg event text exampi ITALY Digital 578 000 MHz Bandwidth
38. ated by a tools sec2ts thats encapsulate sections into ts packets it works this way sec2ts 17 lt firstsdt sec gt firstsdt ts sdt sec is the section of the sdt 17 is the well known pid number for the sdt stream To generate the sdt sec we need to use a different language called python have a look at firstsdt py here is reported the main part bees Service Description Table ETSI EN 300 468 5 2 3 sdt service_description_section transport_stream_id 1 demo value an official value should be demanded to dvb org original_network_id 1 demo value an official value should be demanded to dvb org service_loop service_loop_item service_ID 1 demo value EIT_schedule_flag 0 0 no current even information is broadcasted 1 broadcasted EIT_present_following flag 0 0 no next event information is broadcasted 1 yes running status 4 4 service is running 1 not running 2 starts in a few seconds 3 pause free CA mode 0 0 means service is not scrambled 1 means at least a stream is scrambled service_descriptor_loop service_descriptor service_type 1 digital television service service provider name Avalpa service name Avalpa 1 This python script can be executed with firstsdt py and will generate sdt sec You can edit firstsdt py to change the service_name value and then execute it again to generate the new sdt sec mc e firstsdt py After you located and changed the service name
39. bled No lt CC Errors 4 a Type NIT actual P 17 SDT actual 1 46 kbps 0 01 Gf 1031 PMT 2 9 kbps 0 02 Bitrate 2 891 bps 0 02 sows PCR No Scrambled No CC Errors 4 Type PMT 2064 MPEG 2 Video 1 84 Mbps 13 8 2068 MPEG 1 Video 432 kbps 3 3 8191 Null packets 11 0 Mbps 82 8 Ne H PIDATSAGrd Messages qa x Trace bar ax 06 12 2008 12 23 44 Input signal detected 06 12 2008 12 23 45 Synchronised to stream with 188 byte packets n 4 p Info System 7 Bit rate TR 101 290 Ready 188 Byte TsRate 13 270 656bps 17 2 Mode DVB ASI SDI DTU 245 at 0x01 REC i DVB Mede 00 amp X short term Gils 1 100ms Gy gt W me 2 1 ASI SDI DTU 245 P No decoding lt Video Audio gt Normal y PID info 7 P 0 PAT 2 9 kbps 0 02 M 16 NIT actual 1 42 kbps 0 01 P 17 SDT actual 1 49 kbps 0 01 PS 1031 PMT 2 9 kbps 0 02 X 2064 MPEG 2 Video 2 3 Mbps 17 3 JJ 2068 MPEG 1 Audio 188 kbps 1 4 8191 Null packets 10 8 Mbps 81 2 Hes Indicator Erors Time of Last Error Error Message 0 0 E 0 S Z 0 S 103 2008 06 13 17 41 06 Maximum allowed PCR accuracy on PID 2064 has been exceeded allowed 50 0 S 3 0 S 0 5 F 1 2008 06 13 17 41 04 No table with table id Ox4E for more than 2 00s EITpf_Actual_repetition_rule 0 E
40. c receive tool will extract a dsmcc file system from a transport stream file mkfifo output sec mkdir outputdir ts2sec ocdirl ts 2003 gt output sec amp dsmcc receive outputdir 100 2003 OxB lt output sec The first command will extract sections from a given PID 2003 in the example into a transport stream file the second will output the dsmcc filesystem in the outputdir directory however to process the dsmcc it needs to know the PID 2003 and the component tag OxB 100 is a cache value it specifies that it can store up to 100 sections even if it s not sure if they belong to the current dsmcc or not 54 http www avalpa com Avalpa Broadcast Server user manual Multiplexing a Multiple Program Transport Stream from local files mpts To broadcast two or more programs at the same time the very concept of a multiplex creating a multi program transport stream AKA MPTS you basically add more audio ts and more video ts file to tscbrmuxer and signal the streams with the psi table for a complete example download These python scripts ends with a system command invoking sec2ts so they directly generates ts files without the need to execute manually sec2ts so execute them to generate the psi ts files Audio and video are already multiplexed into mptsav ts files Have a look at mptsconfig py execute it with mptsconfig py and then start muxing and playing remember you need a fifo mkfifo myfirstfifo ts tscbrmuxer
41. cation needs a reference object placed in the object carousel so it s necessary to create a Stream Event Object into the file system you want to broadcast that s possible with steo py Have a look at the steo py script it will generate three files eid ename tap if you put these three in a directory inside the object carousel like test event or example event the carousel generator will create a Stream Event Object instead of a directory This is a special in band signaling i tap str event use tap tap set id 0 assocTag OxD association tag defined into PMT for the Stream Event taps Taps taps_count 1 tap_loop tap event_count 3 number of events event_names Event_names eventnames_count event_count event name loop event 1 event 2 event 3 name of the events event_ids Event_ids eventids count event count event id loop 1 2 3 id of the events Here is how it looks like in ocdir2 the generated files eid ename and tap Lorenzo nb lpallara OpenCaster example config ls la ocdir2 total 20 drwxr xr x 3 lorenzo lorenzo 4096 2007 12 04 12 17 drwxr xr x 5 Lorenzo lorenzo 4096 2008 06 10 02 06 52 http www avalpa com Avalpa Broadcast Server user manual rw r r 1 lorenzo lorenzo 21 2007 12 04 12 17 here is carousel2 drwxr xr x 2 lorenzo lorenzo 4096 2007 12 04 12 17 test event rw r r 1 Lorenzo lorenzo 3796 2007 12 04 12 17 Testst
42. cifies that e the carousel directory to marshal is ocdir1 e the association tag and or Component tag to use for PMT and AIT is OxB 11 e the version of the modules and sections of the carousel is 5 e the pid of the stream is 2003 e the id of the carousel to use in the PMT is 7 e the carousel will be compressed as much as possible it can prevent update notify on buggy decoder e no padding e delete temp files e default block size is 4066 maximum e the update flag is set off e the head of the carousel DSI DII SGW will be sent once at carousel start and once 41 http www avalpa com Avalpa Broadcast Server user manual at carousel middle Running again the command with a different version number will generate a new ocdir1 ts marshalling again the directory oc update sh ocdirl 0xB 0x6 2003 7 1 0 0 4006 1 2 MHPIMHEG5 signalling mhp Now that we have learnt how to marshal a file system the big thing is that in the file system we can bring to an interactive decoder the applications We need to insert the Application Information Table signalling if we want the interactive decoders to be aware of applications and we also need to properly set up DSMCC references The complete basic workflow at decoder side for receiving applications is 1 the decoder tunes the channel 2 the decoder parses the AITs signalled by the PMT 3 the decoder presents to the user the application list got from the AITs it can be necessary
43. defined as all the other tables have a look at the Stream Event defined in mhpconfig2 py s Stream Event F He ste stream event section event id 1 stream event descriptor loop stream event do it now descriptor event id 1 private data event 1 private data 1 version_number 1 section_number 0 last section number 0 This event has id 1 and brings some private date in the payload event 1 private data This event is a Do It Now Event the only kind of stream event supported by OpenCaster and actually the only one supported among all MHP decoders Do It Now means that as soon as the decoder receive the event it should be sent to the applications waiting for it Also HbbTv supports stream events with the same generation process 49 http www avalpa com Avalpa Broadcast Server user manual To have the demo running execute for mhp streamevents mhpconfig2 py oc update sh ocdirl OxB 5 2003 1 2 0 0 4066 0 2 oc update sh ocdir2 OxC 5 2004 2 2 0 0 4066 0 2 tscbrmuxer b 2300000 firstvideo ts b 188000 firstaudio ts b 3008 firstpat ts b 3008 firstpmt ts b 1500 firstsdt ts b 1400 firstnit ts b 1000000 ocdirl ts b 1000000 ocdir2 ts b 2000 firstait ts b 2000 firstste ts b 8770084 null ts gt myfirstfifo ts amp tsstamp myfirstfifo ts 13271000 gt mysecondfifo ts amp tsrfsend mysecondfifo ts mt OFDM mC QAM16 mG 1 4 mc 2 3 mf 578 Now you can tune the decoder and look for t
44. e class Lorenzo nb lpallara OpenCaster example config ls la ocdir2 test event total 20 drwxr xr x 2 lorenzo lorenzo 4096 2007 12 04 12 17 drwxr xr x 3 lorenzo lorenzo 4096 2007 12 04 12 17 rw r r 1 lorenzo lorenzo 7 2007 12 04 12 17 eid rw r r 1 lorenzo lorenzo 29 2007 12 04 12 17 ename rw r r 1 lorenzo lorenzo 8 2007 12 04 12 17 tap When the applications querys the test event object it will find out that can register to three different events 1 2 3 as described by steo py These three event are sent over the PID specified into the PMT and into steo py look for the component tag both in steo py and mhpconfig2 py stream_loop_item stream_type 12 Stream Event stream type elementary PID stel pid element_info_descriptor_loop stream identifier descriptor component tag OxD How to receive stream events on a MHP application is out of the scope of this A document but you will find a java example application in the OpenCaster package The complete workflow after the application is started is 1 the decoder executes the application TestSte 2 the application looks for test Stream Event Object generated by steo py and placed into the DSMCC at generation time 3 the application subscribe to event 1 4 the application receives event 1 from the firstste ts generated by mhpconfig2 py 53 http www avalpa com Avalpa Broadcast Server user manual DSMCC receive mhp The dsmc
45. ery time you edit so the decoder will compare its version with the new one and update the table section_number 0 last section number 0 Service Description Table ETSI EN 300 468 5 2 3 this is a basic SDT with the minimum desciptors OpenCaster has a big library ready to use K HH sdt service_description_section transport_stream_id avalpa_transport_stream_id original_network_id avalpa_original_transport_stream_id service_loop service_loop_item service_ID avalpal_service_id EIT_schedule_flag 0 no current even information is broadcasted 1 broadcasted EIT_present_following flag 0 no next event information is broadcasted 1 yes running status 4 service is running 1 not running 2 starts in a few seconds 3 pause free_CA_mode 0 service is not scrambled 1 means at least a stream is scrambled service_descriptor_loop service_descriptor service_type 1 digital television service service_provider_name Avalpa service_name Avalpa 1 l l version_number 1 you need to change the table number every time you edit so the decoder will compare its version with the new one and update the table section_number 0 last section number 0 Program Map Table ISO IEC 13818 1 2 4 4 8 this is a basic PMT the the minimum desciptors OpenCaster has a big library ready to use K Fh OE pmt program_map_section program_number avalpal_service_id PCR_PID 2064 program info
46. etworking with tsudpsend a tool for broadcasting using multicast to manage this you can try tsudpsend sample ts 224 0 1 2 12345 13271000 The first problem we face is that sample ts is too short and you won t have enough time to tune and search the service on the set top box so let s introduce a tool tsloop File View Settings Audio Video Navigation Help SIR lnm a mom EE gi 0 00 00 0 00 x1 0 avalpacube m2t This tool will put the transport stream file on loop generating a new endless stream where the original file sample ts is repeated Tsloop is a very simple tool and will just fix the continuity counter at transport level so there is not a transport error This is perfect for broadcasting data but not audio and video because at the end of the stream the clock of audio and video will go back in time Tolerant decoders will detect a time skew on the stream clock and correct their internal clock so you won t see any glitch 14 http www avalpa com Avalpa Broadcast Server user manual Many decoders however will have problems with such a simple set up because they are expecting a progressive video and audio time line and a correct buffer management always progressive and forward looking we will address all these issues later on for now to keep first steps easy remind that every 8 seconds there could be some artefacts due to the improper loop and to the modest decoder recovery skills VLC versions afte
47. g a Single Program Transport Stream from local files 20 Generating PSI SI basic tablas sees eee eee 22 WOOL VD STIOO e ae eee de 26 Transport stream bitrate vvs ES 27 IP network ele 28 Avalpa Broadcast Server for advanced datacasting rrrrrnrrarnonernerannrvannrnener 29 EPG rea i na a e E AE Ua Ba been LONE T 29 Telet 33 DSMCC carousels nd data Casting asuavaaassseamusnnesesserttdaauaNN oan 37 DV SS Lae dd ette 37 IES RR Top ZE TER sale a akser GUN SST 40 WOOL OC ele ters HT 40 MHPIMHEGS signalling TTT Al HbbIv Sig naling O 45 Update an object carousel with running applications ccccecsee seen es 46 Signalling Stream Bventg sees crece essere eenn 48 IDSIVIC OKELA Sa TTT 53 Multiplexing a Multiple Program Transport Stream from local files 54 BISS E and CSA o tp t SUPPOrkuademsesjuseae esse 58 Avalpa Broadcast Server Avalpa Web EPG GUL 60 Reierenceuusssasvetasameseerra AEE EEES EEE OO tele 60 3 http www avalpa com Avalpa Broadcast Server user manual Avalpa Broadcast Server for audio video PplayOut cccccecseccececeeeeeeeeenenees 61 Introducuon to INGES ION aeniei iii en n Ea a a E eaa an 61 Extracting Program and Elementary Streams LS20n6S eee eee 63 Analysing mpeg2 video files oesvidoeonto sese 64 Tool sU 66 Analysing audio elementary streams osaudiomnto css ese 67 How to encode mpeg2 digital video files with ffmpeg and mjtools
48. he application Test Stream Event i i i i APPLICATIONS If you execute the application it will start and wait for the Stream Event 50 http Www avalpa com Avalpa Broadcast Server user manual START a 51 http www avalpa com Avalpa Broadcast Server user manual If you didn t notice the multiplexing is using also a firstste ts file this file was generated by mhpconfig2 py and contains the events themselves sent in a loop Obviously this is not the usual behaviour because you don t want to send stream event from the very beginning so you will need to initially mux a null ts instead of firstste ts and replace the stream when it s the right time to send the event cp null ts tempste ts tscbrmuxer b 2300000 firstvideo ts b 188000 firstaudio ts b 3008 firstpat ts b 3008 firstpmt ts b 1500 firstsdt ts b 1400 firstnit ts b 1000000 ocdirl ts b 1000000 ocdir2 ts b 2000 firstait ts b 2000 firstste ts b 8770084 null ts gt myfirstfifo ts amp tsstamp myfirstfifo ts 13271000 gt mysecondfifo ts amp tsrfsend mysecondfifo ts mt OFDM mC QAM16 mG 1 4 mc 2 3 mf 578 cp firstste ts tempste ts to stop sending the event just put the null ts back cp null ts tempste ts So far so good but here it comes the difficult part how the application register to wait for the event The application in order to receive the events has to start executing and register itself to the events To register to event the appli
49. he implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE See the GNU General Public License for more details You should have received a copy of the GNU General Public License along with the OpenCaster software if not write to the Free Software Foundation Inc 51 Franklin St Fifth Floor Boston MA 02110 1301 USA Avalpa Broadcast Server the manual This manual is copyrighted Avalpa 2008 2010 and licensed with MEG Creative Commons Attribution Noncommercial Share Alike 3 0 EY NC SA 8 http www avalpa com Avalpa Broadcast Server user manual First Installation Avalpa Broadcast Server after boot will look for a dhcp address if a ethernet connection is provided If the network connection is not available you can connect monitor keyboard and mouse and do login from the keyboard Login into the system Software will usually run using Avalpa user so you can log in as Avalpa and the password is Avalpa for any need about digital television You can also access the server as a Super user using root user and Avalpa password for system set up like ip address If you are login from a Linux system you can simply use ssh if you are login from a windows system you can use any ssh client like PUTTY http www putty org Setting up a fixed IP address If you want to change the IP address you need to login as root and edit the file etc network interfaces mc e etc network interface
50. her bit rates will introduce some concepts here Bit rates are very important MPEG networks are usually constant bit rate so you will often need to output files at the correct bit rate or you will have a countless number of side effects How do we know the bit rate of the signalling streams MPEG DVB and all the others standards specify the bit rates you just need to pay attention to a detail PSI bit rates are expressed as section per second for example a PAT has to be broadcasted every 500 ms but a PAT as all the other sections can be 1 ts packet up to 23 ts packets depending on its content so bit rate needs to be changed according to the sections size Set the bit rate to the maximum allowed is not a wise choice because 99 of the signal tables are usually 1 or 2 packets so it would result in a big waste of bandwith Plan carefully your bit rates when starting the muxing so you won t need to stop it later on bit rates can t be changed without artefacts and for the decoders the best way to do this is stop all the muxing and restart There is still another point to face before you can broadcast the multiplexed ts the bit rate of the resulting muxed ts is not a bit rate that matches a DVB modulation scheme How can we fix that 21 http www avalpa com Avalpa Broadcast Server user manual An option is to just make some data stream faster or to increase the video bit rate but there is also another choice add a NULL PID filli
51. ilable CAS system but OpenCaster is also able to signal ECM EMM and CAT in the same way as described for the others PSI SI shown in the previous examples so the support is quite complete The scrambling processing is quite computational expensive so pay attention to your cpu usage 60 http www avalpa com Avalpa Broadcast Server user manual Avalpa Broadcast Server Avalpa Web EPG GUI Reference Already installed on the Avalpa Broadcast Server there is a Eletronic Program GUI generator than can configured by web A complete manual is available in Italian and English translation is on the way in the meanwhile a few topics are already covered Check out the guide at http www avalpa com assets freesoft opencaster AvalpaBroadcastWebEPGManual v1 0 pdf Here is an actual screenshot G Applicazioni Risorse sistema amp anale 1 gt GB al mar 1mar 16 44 thomas 0 D canal C Q epg avalpa org cool index php action display deck AALP ioio all Canale 1 Search View Month View Week Login View in GMT wi A g Ma erie 16 44 1 March 2011 Europe Rome March 01 2011 at 15 00 to 17 00 Avventura od emozione Regista Titolo epg avalpa org cool index php action display event amp oid 35816 amp zone 7 ES E EPG usermanual v1 Canale 1 Google Ch 61 http www avalpa com Avalpa Broadcast Server user manual Avalpa Broadcast Server for audio video playo
52. inal_transport_stream_id 1 demo value an official value should be demanded to dvb org avalpal_service_id 1 demo value avalpal_pmt_pid 1031 Network Information Table this is a basic NIT with the minimum desciptors OpenCaster has a big library ready to use nit network_information_section network_id 1 network_descriptor_loop network_descriptor network_name Avalpa l transport_stream_loop transport_stream_loop_item transport_stream_id avalpa_transport_stream_id original_network_id avalpa_original_transport_stream_id transport_descriptor_loop service list descriptor dvb service descriptor loop service descriptor loop item service ID avalpal service id service type 1 digital tv service type l l l version_number 1 you need to change the table number every time you edit so the decoder 24 http www avalpa com Avalpa Broadcast Server user manual will compare its version with the new one and update the table section_number 0 last_section_number 0 Program Association Table ISO IEC 13818 1 2 4 4 3 pat program_association_section transport_stream_id avalpa_transport_stream_id program_loop program_loop_item program_number avalpal_service_id PID avalpal_pmt_pid program_loop_item program_number 0 special program for the NIT PID 16 1 version_number 1 you need to change the table number ev
53. ip address and port and the bit rate of the transfer The first thing to keep in mind is that the bit rate is the transport stream bit rate and not the ip packets bit rate As far as there is enough bandwidth the file will be transferred and due to the TCP properties we won t miss any packet Another option is to use UDP packets instead of TCP but this implies that same packet could be lost or repeated so there is no guarantee that a transport stream received from an UDP stream is going to be error free and so it s a risk to use UDP asa contribution link between OpenCaster tools without implementing some recovery strategy The main reason to send a transport stream over UDP is to enable multicast for end user distribution the decoder receiving the stream will implement the necessary algorithms of error concealment to manage packet loss while decoding the stream in the same way it recovers from broadcast errors for weak signal conditions Why not RTP Maybe we will support RTP in the future for now it is not available On some scenarios can make sense to pay for more memory in the receiver than pay for network bandwidth so to reduce network usage NULL packets are removed from the transport streams and this can lead to migrate a Constant Bit Rate transport stream into a Variable Bit Rate transport stream This happens if NULL packets are not uniform inserted as shown in the chapter Multiplexing a Single Program Transport Stream In
54. ithout Avalpa Broadcast Server dedicated DVB hardware and software if OpenCaster is correctly installed configured and managed Check the chapter Ip network tools before continue for a brief explanation of the design choices Tool tsorts mpts Tsorts tool will listen to input network and grab a packet from it if it s ready or replace it with a null packet if there was a transmission problem and the packet couldn t be delivered here is an example setup tsudpreceive 224 0 1 2 1234 gt input ts amp torts input ts null ts gt tsored ts amp tspcrrestamp tsored ts 24130000 gt stamped ts amp tsudpsend stamped ts 224 0 1 2 3 1234 24130000 Tsorts will also add null packets if the incoming stream is not loosing packets but its bit rate is lower than the specified Tspcrrestamp will take care to restamp the pcr so the jitter of the null pid insertion is reduced To achive multiplexing from more input it is necessary to increase tsudpreceive processes let s check an example where two incoming streams are muxed and then sent to another multicast group in output to be received by an ip DVB T modulator tsudpreceive 224 0 1 1 1234 gt inputl ts amp tsudpreceive 224 0 1 2 1234 gt input2 ts amp torts inputl ts null ts gt tsoredl ts amp torts input2 ts null ts gt tsored2 ts amp tscbrmuxer b 2000000 tsoredl ts b 3000000 tsored2 ts 0 13271000 null ts gt muxed ts amp tspcrrestamp muxed ts 13271000 gt stamped t
55. lar for the other DVD encodings bb video pes bb audio pes bb pes length bb2 video pes bb2 audio pes and finally bb2 pes length mkfifo video ts mkfifo audio ts mkfifo muxed ts mkfifo stamped ts pesvideo2ts 2064 25 112 2900000 1 ed video pes bb video pes bb2 video pes gt video ts amp pesaudio2ts 2068 1152 48000 384 1 ed audio pes bb audio pes bb2 audio pes gt audio ts amp tscbrmuxer b 2800000 video ts b 188000 audio ts b 3008 firstpat ts b 3008 firstpmt ts b 1500 firstsdt ts b 1400 firstnit ts b 10174084 null ts gt muxed ts amp tspcrstamp muxed ts 13271000 gt stamped ts amp tsrfsend stamped ts mt OFDM mC QAM16 mG 1 4 mc 2 3 mf 578 This will output three files with audio and video connected seamlessly please notice some points about why this works e ed bb and bb2 have all the same bandwidth both audio and video and all the bandwidths are CBR e the first GOP of every video is closed e pesvideo2ts controls vbv fullness all the time and also on the switch between streams At every connection some interesting informations are printed pesaudio2ts closing ed audio pes closed pesaudio2ts warning missed ed audio pes length file pesaudio2ts opening bb audio pes open pesaudio2ts sync bb audio pes new presented audio frame will be at 57164400 63 5 1600 sec last presented audio frame was at 57161520 635 1280 sec pesvideo2ts closing ed video pes closed pesvideo2ts opening bb video pes open pes
56. me per second if you properly run esaudio2pes and esvideo2pes from the previous instructions you should have a video pes starting like this pes header 00 00 01 e0 video stream number 0 header length 10 Presentation Time Stamp is 3600 0 0400 sec Decode Time Stamp is 0 0 0000 sec pes header 00 00 01 e0 video stream number 0 header length 10 Presentation Time Stamp is 14400 0 1600 sec Decode Time Stamp is 3600 0 0400 sec And an audio pes starting with pes header 00 00 01 c0 audio stream number 0 pes size 392 header length 5 Presentation Time Stamp is 3600 0 0400 sec pes header 00 00 01 c0 audio stream number 0 pes size 392 header length 5 Presentation Time Stamp is 5760 0 0640 sec pes header 00 00 01 c0 audio stream number 0 pes size 392 header length 5 Presentation Time Stamp is 7920 0 0880 sec 75 http www avalpa com Avalpa Broadcast Server user manual Encoding with x264 This section will show how to use x264 to encode h264 video instead of mpeg2 video The current example will show how to broadcast a 1080p24 video The video format is actually a non common choice for RF broadcasting and not standardized for DVB but it suites local networks use cases VOD and it is the simpler example on how to start as it doesn t require telecine techniques ffmpeg i big buck bunny 1080p h264 mov movie OpenCaster tutorials encodingHD logo_tv png wm in wm overlay 0 0 0 0 out f yuv4mpeg
57. nfident with the content of these basic chapters Every chapter also states where to find tutorial files The line written in this format are command line to be typed as is in the terminal Example tsrfsend sample ts mt OFDM mC QAM16 mG 1 4 mc 2 3 mf 578 The following symbols will serve as follow Symbol Description Pay attention to this note it should be a hint for a smarter usage of the software Kn kl 11 http Www avalpa com Avalpa Broadcast Server user manual Beware you can get some undesirable effect if you don t understand instructions and follow them carefully Help This part is not completely up to date or finished maybe j you can help us would you like Then in the paragraphs where there are practical exercises using materials to be found in the OCtutorials directories on the server we list them in advance with such a graphical hint OCTutorials sample ts Interesting and basic readings We believe it s not healthy to run this software and read this book if you don t have already some idea of the digital television technology so at least please read Appendix by prof Antonio Navarro from Aveiro University for an introduction for a more deeper overview have a look at A Guide to MPEG Fundamentals and Protocols Analysis freely available by Tektronix Good books to get into the details are Digital Video and Audio Broadcasting Technology by W Fisher and
58. ng stream tscbrmuxer b 2300000 firstvideo ts b 188000 firstaudio ts b 3008 firstpat ts b 3008 firstpmt ts b 1500 firstsdt ts b 1400 firstnit ts b 10774084 null ts gt sample ts A null stream is a stream made of empty packets OxFF with fixed PID 8191 to get the required bit rate you need to add a null ts to the multiplexing with the missing bit rate to reach the required one In the example there is a massive insertion of null packets more than 10Mbps but this is just an example Noticed that also sample ts from the first tutorial was generated in the same way just to make thing easier to start To output the final result use tscbrmuxer instead of tsloop from the previouse example mkfifo myfirstfifo ts mkfifo mysecondfifo ts tscbrmuxer b 2300000 firstvideo ts b 188000 firstaudio ts b 3008 firstpat ts b 3008 firstpmt ts b 1500 firstsdt ts b 1400 firstnit ts b 10774084 null ts gt myfirstfifo ts amp tsstamp myfirstfifo ts 13271000 gt mysecondfifo ts amp tsrfsend mysecondfifo ts mt OFDM mC QAM16 mG 1 4 mc 2 3 mf 578 On the other hand if you are going to broadcast a TS over an UDP network Where there are no fixed bit rates you will be better to avoid sending Constat Bit Rate null packets so the final batch will be mkfifo myfirstfifo ts mkfifo mysecondfifo ts tscbrmuxer b 2300000 firstvideo ts b 188000 firstaudio ts b 3008 firstpat ts b 3008 firstpmt ts b 1500 firstsdt ts b 1400 firstnit ts gt myfirstfifo ts
59. ning 1 not running 2 starts in a few seconds 3 pause free_CA_mode 0 service is not scrambled 1 means at least a stream is scrambled event_descriptor_loop short_event_descriptor 150639 language code ita event name epg event name text this is an epg event text example 1 l version_number 1 section_number 0 last section number 1 pay attention here we have another section after this last segment section number 1 eit follow event information section table id EIT ACTUAL TS PRESENT FOLLOWING service id avalpal service id transport stream id avalpa transport stream id original network id avalpa original transport stream id event loop event loop item event id 2 30 http www avalpa com Avalpa Broadcast Server user manual start_year 108 since 1900 start_month 06 start_day 10 start_hours 0x23 start_minutes 0x30 start_seconds 0x00 duration_hours 0x12 duration_minutes 0x00 duration_seconds 0x00 running status 4 service is running 1 not running 2 starts in a few seconds 3 pause free_CA_mode 0 service is not scrambled 1 means at least a stream is scrambled event_descriptor_loop short_event_descriptor 150639 language code ita event name epg event name 2 text this is the following text example l l version_number 1 section_number 1 this is the second section last_section_number 1 l
60. ntified by the same PID In most applications time division multiplexing will be used to decide how often a particular PID appears in the transport stream Transport stream brings also a logic representation of the carried content mainly with the concept of programs A single program is described by a Program Map Table PMT which has a unique PID and the elementary streams associated with that program have PIDs listed in the PMT For instance a transport stream used in digital television might contain three programs to represent three television channels Suppose each channel consists of one video stream one or two audio streams and any necessary metadata A receiver wishing to decode a particular channel merely has to decode the payloads of each PID associated with its program It can discard the contents of all other PIDs To make sure you can broadcast and receive a transport stream check your set up with the sample TS presenting only one video with one audio After login change into directory start here cd start here If your server is equipped with RF output you will need to set modulation parameters tsrfsend sample ts mt OFDM mC QAM16 mG 1 4 mc 2 3 mf 578 if your server is equipped with DVB ASI from you will have tsasisend sample ts r 13271000 13 http www avalpa com Avalpa Broadcast Server user manual In both cases or if you are using OpenCaster without DVB hardware you can also always output over IP n
61. oder will follow 55 http www avalpa com Avalpa Broadcast Server user manual Installation gt Manual Scanning L Your digital receiver found TV 3 Radio 0 Interactive 0 TV List 1 Avalpa 1 gt gt Avalpa z 3 Avalpa3 56 http www avalpa com Avalpa Broadcast Server user manual No EPG ITALY Digital 578 000 MHz Bandwidth 8 MHz FFT 8 K PID 065 PID 069 P PID 065 OAL LOLOL LOO O ELLE BELO O ELLE EOCENE EER EE ELE LEE i TT w 2 Thu Jan 01 1970 02 44 Avalpa 2 ITALY Digital 578 000 MHz Bandwidth 8 MHz FFT 8 K PID 2066 PID 2070 P_PID 2066 13 Thu Jan 01 1970 02 44 Avalpa 3 Finally let s check the analyser again for the services and their PCR 57 http www avalpa com Avalpa Broadcast Server user manual StreamXpert No record file Analyser Record View Help DVBMode 00 amp X short term Gls Ti100ms Gy gt B Me 2 1 ASI SDI DTU 245 0 No decoding lt Video v Audio eNom G Hon E 0 PAT 29 kbps 0 02 FT 16 NIT actual 1 49 kbps 0 01 E 17 SDT actual 1 47 kbps 0 01 DD 1031 PMT 29 kbps 0 02 E 1032 PMT 2 9 kbps 0 02 E 1033 PMT 2 9 kbps 0 02 MPEG 2 Video 2 2 Mbps 16 9 MPEG 2 Video 1 96 Mbps 14 8 MPEG 2 Video 2 0 Mbps 15 2 MPEG 1 Audio 190 kbps 1 4 MPEG 1 Audio 185 kbps 1 4 MPEG 1 Audio 190 kbps 1 4 8191 Null packets 6 5 Mbps 48 7 B 8 8 8 6 8 8 B 0 A
62. ol is available on Appendix Transport stream offers features for error correction for transport over unreliable media and is used in broadcast networks such as DVB Avalpa Broadcast Server inputs are usually non transport stream files stored on hard disk while output is a transport stream suitable for DVB headend integration through DVB ASI or UDP and for stand alone broadcasting through RF modulation VOD or IPTV For data broadacasting only is also possibile to output DVB packets over parallel port on this interface jitter is unsuitable for video broadcasting The DVB TI S C output can be directly received by Set Top Boxes and Integrated Digital TeleVisions Latest version of the Avalpa Broadcast Server features also re multiplexing features using as inputs DVB T S C pci boards and or udp multicast packets Avalpa Digital Engineering Avalpa is an Italian company working in the digital television market since a long time with a quite broad range of products and services for broadcaster great skills creativity and an open mind attitude Avalpa http Awww avalpa com is the main developer of OpenCaster and wrote this manual too Avalpa offering include also e Custom installations and maintenance of solutions e Integration with others DVB systems e Training support and consultancy e Further development of features and customization Contacts e a venturi avalpa com CEO e pallara avalpa com CTO e info avalpa com for general
63. on 0x00 descriptors name_descriptor name another bin l dsi SuperGroup PATH transactionId 0x80000000 version s i dsi set compatibilityDescriptor 000 000 as specified in etsi 102 006 dsi addGroup g1 dsi addGroup g2 Finally a script will take care of convert all the generated sections to a transport stream file ssu update sh datacarousel 2003 0 The script file gets the sections generated by ssu data generation py a converts them to transport stream using sec2ts The last part is the usual multiplexing carried out with these commands tscbrmuxer b 2300000 firstvideo ts b 188000 firstaudio ts b 3008 firstpat ts b 3008 firstpmt ts b 1500 firstsdt ts b 1400 firstnit ts b 1000000 datacarousel ts b 9774081 null ts gt fifomuxed ts amp tstdt fifomuxed ts gt fifotimed ts amp tspcrstamp fifotimed ts 13271000 gt fifostamped ts amp tsrfsend stamped ts mt OFDM mC QAM16 mG 1 4 mc 2 3 mf 514 amp 40 http www avalpa com Avalpa Broadcast Server user manual Interactive TV support Interactive television standards usually requires a data casting more complex than dvb ssu so instead to describe modules one by one as shown in ssu data generation py followed by ssu update sh an automatic tool will take care of all the processing Tool oc update sh Usage oc update sh object_carousel_directory association_tag module_version dsmcc_pid carousel_id compress mode padding on
64. on tag identifys the carousel it is used also while generating the DSMCC with oc update sh and referenced by the AIT use 0 some default values follow don t change them selector lenght 0 transaction_id 0x80000000 timeout OxFFFFFFFF private data stream_identifier_descriptor component_tag OxB it is the same as the assocation tag some decoders will look for the component tag others for the association tag the same value should be used carousel_identifier_descriptor carousel_ID 1 carousel id number it s a different number from association component tag but it has a similiar purpouse identifying the carousel format_ID 0 no enhanced boot supported private data data_broadcast_id_descriptor data_broadcast_ID 240 240 is the code specifying this is DSMCC MHP 262 for mheg5 ID_selector_bytes for mheg5 you need selector bytes 001 001 000 000 l e238 N B To add another AIT stream or another DSMCC you will have to add more stream_loop_items In mhpconfig py you can also find an AIT example that will generate an firstait ts transport stream file let s have a look at it Application Informaton Table ETSI TS 101 812 10 4 6 ait application information section application type DVB J application type common descriptor loop application loop here we list only 1 application adding another application loop item will signal a sec
65. ond application in the sam AIT you can signal applications in the same AIT or more AITs application loop item organisation id 10 this is a demo value dvb org should assign an unique value application_id 1001 should be unique for every organisation id in the same program application_control_code 2 is PRESENT the decoder will add this application to the user choice of application 1 is AUTOSTART the application will start immedtiatly to load and to execute 3 is DESTROY it will signal to the application to stop executing is KILL it will stop execute the application application_descriptors_loop transport protocol descriptor protocol id MHP OC protocol id the application is broadcasted on MHP DSMCC transport protocol label 1 carousel id remote connection 0 component tag OxB carousel common tag and association tag 1 application descriptor application profile 0x0001 Profile and MHP version version major 1 version minor 0 version micro 43 http www avalpa com Avalpa Broadcast Server user manual service_bound_flag 1 the application is expected to die on service change 0 will wait after the service change to receive all the AITs and check if the same app is signalled or not visibility 3 the applications is visible to the user 1 the application is visible only to other applications application_priority 1 is lowset when more than 1 app is executing transport_protocol_label
66. ools as shown up to now you will probably need to filter some packets with tsmask or change pid number with tsmodder and so on it all depends from the incoming streams If you can configure incoming streams to be only content pids like audio video and teletext the final setup won t differ from the multiplexing example of mpts tutorial where audio and video ts files are replaced by pipes 84 http www avalpa com Avalpa Broadcast Server user manual Appendix A Acronyms glossary and references The most frequent acronyms and something about it AIT Application Information Table ETSI TS 102 812 CBR Constant Bit Rate DVB Digital Video Broadcasting http www dvb org DVB ASI DVB Asynchronous Serial Interface EN 50083 9 DSM CC Digital Storage Media Command and Control ISO IEC 13818 6 EN 301 192 ETSI European Telecommunications Standards Institute the standardization body for many digital television standards http www etsi org GOP Group Of Pictures a sequence of frames on a video stream compressed together usually 12 or 15 IP Internet Protocol rfc 791 MHP Multimedia Home Platform ETSI TS 102 812 MPE Multi Protocol Encapsulation ISO IEC 13818 6 EN 301 192 MHEG5 ISO IEC 13522 5 MPEG Motion Picture Expert Group http multimedia telecomitalialab com MPTS Multi Program Transport Stream a MPEG2 TS carrying more then one service NIT Network Information Tablet ISO IEC 13818 1 NVOD Nea
67. or update_versioning flag 0 no version change update_version 1 increment this at update change selector_bytes 1 l private_data_bytes 1 stream_loop_item stream_type 11 data stream type elementary_PID avalpal_dsmcc_pid element info descriptor loop stream identifier descriptor component tag dsmccB association tag 1 l DVB SSU carousel is simpler than interactive applications and just requires each file to be transmitted to be specified as a module the last part of ssu data generation py configuration file shows how to specify them for a complete description of values check ETSI TS 102 006 DSMCC description gl Group PATH DII 1 sec transactionId 0x80000002 downloadId 0x00000001 blockSize 4066 39 http www avalpa com Avalpa Broadcast Server user manual version gl set compatibilityDescriptor comp descl pack modules Module INPUT ocdirl RootRelook2100 moduleIld 0x0001 moduleVersion 0x00 descriptors name_descriptor name a bin Module INPUT ocdirl RootRelook2101 moduleId 0x0002 moduleVersion 0x00 descriptors name_descriptor name a bin g2 Group PATH DII 2 sec transactionId 0x80000004 downloadid 0x00000002 blockSize 4066 version il g2 set compatibilityDescriptor hello modules Module INPUT big file raw moduleId 0x0010 moduleVersi
68. orts a signal is locked the scan finds 1 service Avalpa 1 15 http www avalpa com Avalpa Broadcast Server user manual Installation K Your digital receiver found TV 1 Radio 0 Interactive 0 Digital 578 000 MHz BW 8 MHz FFT 8 K IT MENU exit menu Check the modulation parameters that the decoder is using actually match the one from the command line the signal status strength is also high Installation E Country ITALY Scan Mode Digital Channel Number Frequency Bandwidth Guard Interval FFT Mode Signal Statu EXIT MENU 16 http www avalpa com Avalpa Broadcast Server user manual let s check the service Avalpa 1 3 1 hu Jan 01 1970 02 38 Avalpa 1 you will probably notice a lot of artefacts and the colour bars won t turn smoothly over Avalpa logo let s check what s happening with some analyser tool 17 http www avalpa com Avalpa Broadcast Server user manual We will show as example some screenshots from StreamXpert analyzer by Dektec here they come gt Analyser Record View Help i DVB Mede 00 amp X short term Gls Ti100ms Gy gt W me 2 1 ASUSDI DTU 245 0 Avalpa1 ID 1 Video 2064 MPEG 2 Video Audio v Norma den L info 5 0 PAT 29 kbps 0 02 Bitrate 2 891 bps 0 02 PCR No e Scrambled No CC Errors 4 e Type PAT GC 16 NIT actual 1 40 kbps 0 01 e Bitrate 1 404 bps 0 01 PCR No Scram
69. pes length is 57286800 ticks of 90Khz so 1 frame is 90000 25 frame per second 3600 pts ticks and 57286800 3600 15913 frames 25 fps 636 52 seconds of video We need to compare this with the audio length to ensure the audio is a little shorter than the video this is the only requirement to chain two videos encoded as just described ed audio pes size is 10530284 1 frame is 1152 sample and sample rate is 48000 so 10530284 384 14 26458 frames 1152 48000 634 992 seconds of audio In this case audio is shorter so there is no problem otherwise esaudio2pes ed mp2 1152 48000 384 1 3600 57286800 gt ed audio pes would have cut the audio before the end of the video To have some video clips for the playout you should repeat the same commands for another short Big Buck Bunny the second release still courtesy from the Blender Foundation available from http www archive org details BigBuckBunny To match our set up in the next chapters you should encode vTs_05_1 voB and VTS 02 1 V0B Audio and video initial synchronization The first PTS value is important for synchronization between audio and video that s because it is necessary to synch the presentation of the first video frame and the first audio frame First of all let s make sure with pesinfo that PTS of the first video frame matches the PTS of the first audio frame better if they both are 3600 ticks of the 90 KHZ clock that s 0 04 ms that s 1 video frame at 25 fra
70. pesaudio2ts closing ed audio pes closed pesaudio2ts opening bb audio pes open pesaudio2ts sync bb audio pes new presented audio frame will be at 57290400 636 5600 sec last presented audio frame was at 57161520 635 1280 sec pesvideo2ts closing ed video pes closed pesvideo2ts opening bb video pes open pesvideo2ts sync bb video pes new presented video frame is at 57290400 636 5600 sec decode time stamp is at 57286800 636 5200 sec As you can read now bb audio pes new presented audio frame will be at 57290400 636 5600 sec bb video pes new presented video frame is at 57290400 636 5600 sec To recover from an out of synchronization after it is signalled you will need to do some mathematics and add at the current audio pes length value the missing time so that while passing to the new stream from the current the synch is gained In the next pages a gallery of some screen shots from different analysers is shown 78 http www avalpa com Avalpa Broadcast Server user manual Packet 152434 Speed 2 PID Time secs Avg Jitter ms Max Jitter ms Max Jitter Packet Avg Interval ms PER Drift ms 2064 17 243458 0 0001 0 0296 PCR 0 39 5495 0 0435 E C DE VK Tafe PCR Analysis VK Tafe T STD Analysis 79 http www avalpa com Avalpa Broadcast Server user manual r 4 amp StreamGURU MPEG Analyzer Loe es Main TSFeed Record CA Tools View Help n X A Q
71. pipe x264 level 4 0 nal hrd cbr vbv bufsize 2000 bitrate 7200 keyint 12 vbv init 0 o bb x264 hd video pes pesvideo2ts 2066 24 38 b7200000 7600000 bb x264 hd video pes gt video ts ffmpeg i big buck bunny 1080p h264 mov vn acodec ac3 ar 48000 ab 448k audio24p ac3 since we are dealing with HD let s also put 5 1 audio esaudio2pes audio24p ac3 1536 48000 1792 1 3750 gt audio pes pesaudio2ts 2069 1536 48000 1792 audio pes gt audio ts it will also require to change psi to signal correctly the service in a few places for nit sdt service type 0x19 avc hd digital tv service type for pmt stream loop stream_loop_item stream_type 0x1B avc video stream type elementary_PID 2066 element_info_descriptor_loop stream_loop_item stream_type 6 private elementary_PID 2069 element info descriptor loop ac3 descriptor component type flag 0 bsid flag 0 mainid flag 0 asvc flag 0 additional info 1 finally tscbrmuxer rates are b 7600000 video ts b 470000 audio ts 76 http www avalpa com Avalpa Broadcast Server user manual Play out scheduling from command line first file mux Here is the first example of audio and video play out script we assume you already encoded the file as explained in Audio and video real case encoding with ffmpeg the file names will be ed video pes ed audio pes ed pes length and simi
72. playing the video so the usual number of GOP size for broadcasting is 12 less than half a second at 25 frames per second 12 1 25 0 48 sec Closed gop have a different sequence they start with an picture with time reference 1 and allow them to be the start of an encoded video This peculiar GOP feature allows also 66 http www avalpa com Avalpa Broadcast Server user manual GOP to be chained without re encoding the video we will get on this topic later on Tool vbv Another interesting tool is mpeg2videovbv that s Video Buffer Verifier the tool tries to simulate a mpeg2 video decoder buffer mpeg2videovbv video es will print underrun and overrun of the buffer if they happen or stay quiet if the video stream respects the limits reporting found 0 errors at the end If vbv reports error it is a hint that the video was encoded with a bit rate that s not enough constant N b this tool is a simulator that tries to be strict sometime a video stream happens to work properly on real decoders as they should be far more tolerant even if vbv reports errors It can also happen a video won t work properly even if vov doesn t complain because buffer fullness is not the only important issue for a proper playback the vbv tool fills the buffer at a constant bit rate CBR but on real transmission the model may look more like many small burst getting an average cbr ness if the burstiness is not properly managed a vb
73. r 0 8 4 are reported to don t work any more with the tutorial files sample ts and firstvideo ts because of these reasons regarding poor clock management so even if VLC works correctly with a real set up of OpenCaster where clock is properly stamped it will fail to show the tutorials until clock management is put in place Check Demonstration chapter for a transport stream that plays correctly on VLC for a longer time On the other Mplayer is able to correctly manage the clock issue mplayer nocache noidx udp 224 0 1 2 1234 Before using tsloop tool we need to introduce an important concept in OpenCaster operations the fifo First In First Out fifo connections are the way OpenCaster tools pass TS packets to each other the packets are usually pulled out from the fifo but later on we will see more complex set ups where pull and push live together The following command creates a fifo mkfifo myfirstfifo ts after you can execute tsloop and the play command together tsloop sample ts gt myfirstfifo ts amp tsrfsend myfirstfifo ts mt OFDM mC QAM16 mG 1 4 mc 2 3 mf 578 The amp at the end of tsloop command is necessary to put the process in background The tsloop command will wait or the second command to pull the data out of the myfirstfifo ts You will be able to receive the stream with a dvb t decoder tuning to 578 MHz the following pictures show the procedure step by step Set top box manual scan menu rep
74. r Video on Demand PAT Program Association Table ISO IEC 13818 1 PID Program IDentifier ISO IEC 13818 1 PMT Program Map Table ISO IEC 13818 1 PTS Presentation Time Stamp ISO IEC 13818 2 PSI Program Signalling Information ISO IEC 13818 1 STB Set Top Box the decoder SPTS Single Program Transport Stream ISO IEC 13818 1 TS Transport Stream ISO IEC 13818 1 VBR Variable Bit Rate VOD Video On Demand PES Program Elementary Stream ISO IEC 13818 1 ES Elementary Stream ISO IEC 13818 1 85 http www avalpa com Avalpa Broadcast Server user manual Appendix B DVB T transmission parameters and net bitrates Available bitrates Mbit s for a DVB T system in 8 MHz channels courtesy Wikipedia Modulation QPSK Coding rate Guard interval 1 4 1 8 1 16 1 32 1 2 4 976 5 529 5 855 6 032 2 3 6 635 7 373 7 806 8 043 3 4 7 465 8 294 8 782 9 048 5 6 8 294 9 216 9 758 10 053 7 8 8 709 9 676 10 246 10 556 Modulation 16 QAM Coding rate Guard interval 1 4 1 8 1 16 1 32 1 2 9 953 11 059 11 709 12 064 2 3 13 271 14 745 15 612 16 086 3 4 14 929 16 588 17 564 18 096 5 6 16 588 18 431 19 516 20 107 7 8 17 418 19 353 20 491 21 112 Modulation 64 QAM Coding rate Guard interval 1 4 1 8 1 16 1 32 1 2 14 929 16 588 17 564 18 096 2 3 19 906 22 118 23 419 24 128 3 4 22 394 24 882 26 346 27 144 5 6 24 882 27 647 29 273 30 160 7 8 26 126 29 029 30 737 31 668 86 http www avalpa com Avalpa Broadcast Server u
75. rder to bitstream order so that the B picture is transmitted after the previous and next pictures it references This introduces a reordering delay dependent on the number of consecutive B pictures The different picture types typically occur in a repeating sequence termed a Group of Pictures or GOP A typical GOP in display order is B1 B2 I3 B4 B5 P6 B7 B8 P9 B10 B11 P12 The corresponding bitstream order is I3 B1 B2 P6 B4 B5 P9 B7 B8 P12 B10 B11 A regular GOP structure can be described with two parameters N which is the number of pictures in the GOP and M which is the spacing of P pictures The GOP given here is described as N 12 and M 2 MPEG 2 does not insist on a regular GOP structure For example a P picture following a shot change may be badly predicted since the reference picture for prediction is completely different from the picture being predicted Thus it may be beneficial to code it as an l picture instead For a given decoded picture quality coding using each picture type produces a different number of bits In a typical example sequence a coded l picture was three times larger than a coded P picture which was itself 50 larger than a coded B picture The number after the picture type is the temporal reference inside the single GOP On broadcasting environment an external additional constraint comes from the user acceptable zapping time because a decoder needs to wait an picture to start dis
76. re multiplexing functions in that case Avalpa Broadcast Sever remultiplexing functions can avoid you additional hardware costs Demonstration You can download a transport stream multiplexed by OpenCaster showing many advanced features at http www avalpa com the key values 15 free software 59 opencaster demo roll The transport stream is ready to be broadcast with a DVB T modulator using QAM 16 guard interval 1 4 and code rate 2 3 you can watch on your tv or stb You can play it on pc by VLC or streamed on IP setting bitrate at 13271000 bps OpenCaster OpenCaster is the GPL v2 open source software developed mainly by Avalpa People and its the heart of Avalpa Broadcast Server Avalpa Broadcast Server is our internal reference system always under tests and runs over a Linux Debian 6 0 Stable system Avalpa Broadcast Server can be requested as it is or you can contact us to integrate customize it for your systems and solutions on the other hand OpenCaster is available as standalone source code download for ts over UDP input output usage on any pc from Avalpa web site www avalpa com to anybody that wants to work on it develop it further or use it as standalone software without dedicate hardware or others functions that doesn t require a complex system set up and or a DB or third parties hardware integration Avalpa Broadcast Server IS NOT ONLY what you get installing OpenCaster on your Linux pc but also 1 AWE Avalpa Web EPG for even
77. ream output but it is not suitable for CBR broadcast so you cannot use with other OpenCaster tools that is why we will always show example starting from pes or es input files Extracting Program and Elementary Streams ts2pes first file mux Avalpa Broadcast Server comes with some tools to analyse Program and Elementary Stream these are the basic operations needed to validate your input files before using them in the play out this section will introduce you also the basic concepts you have to master if you want a smooth play out working without problems on any decoder ts2pes will extract from a transport stream the program elementary stream described with a PID for example ts2pes firstvideo ts 2064 gt videooutput pes A program elementary stream files will be generated usually audio or video pesinfo will report informations about the program elementary streams usage is simple pesinfo videoutput pes Ouput is something like lessi pes header 00 00 01 e0 video stream number 0 header length 5 Presentation Time Stamp is 989100 10 9900 sec pes header 00 00 01 e0 video stream number 0 header length 5 Presentation Time Stamp is 992700 11 0300 sec pes header 00 00 01 e0 video stream number 0 header length 10 Presentation Time Stamp is 1007100 11 1900 sec Decode Time Stamp is 996300 11 0700 sec pes header 00 00 01 e0 video stream number 0 header length 5 Presentation Time Stamp is 999900 11 1100
78. rial is transmitting 4 pages 100 202 302 and 404 Page 100 has also fast link for the others pages connected to colour keys The final look is Avalpa TXT 10 04 2009 15 00 Av pal Av pa2 Av pas Av pa amp Av pa5 pa6 pa7 pas pag pa 10 pa11 pa 12 pa1 pa2 pas pa4 amp pas pa6 pa7 pasg pa9 L L L L L L L L L L L L L L L L L L L L L L L m pmr p pmr pmr pmr p pmr pmr pmr pmr pmr pmr pmr pmr pmr pmr pmr pmr pmr pmr pmr p a a a a a a a a a a a a a a a a a a a a a a a ooooqovoaonownonawawaadwanwadaaoadadd amp Av Av av av av av av av av av av av av aoononoaoaodoaadoaaond gt oe em oe fe ee oe oe GE About the teletext packet generation it can be done with python libraries but requires knowledge of the teletext itself Basic information is presented here and will allow you to properly display text only pages 35 http www avalpa com 202 A 202 1 A 202 2 A 202 53 A 202 4 A 202 5 A 202 6 A 202 7 A 202 8 A 202 9 Avalpa Broadcast Server user manual Avalpa TxX T TO 04 2009 15 01 A 202 1 A 202 2 A 202 3 A 202 4 A 202 5 A 202 76 A 202 7 A 202 8 A 202 9 A 202 710 A 202 11 A 202 12 A 202 10 A 202 11 A 202 12 a 202 1 a 202 2 a 202 53 a 202 4 a 202 5 a 202 6 a 202 7 a 202 8 a 202 9 a 202 1 a 202 2 a 202 3 a 202 74 a 202 5 a 202 6 a 202 7 a 202 8 a 202 9 a 202 1 a 202 1 a 202 10 a 202 11 04 T Er 1 2 15 OO
79. s 1 carousel Id application_name_descriptor application_name Text input example dvb_j_application_descriptor parameters file 1 sample8 xlet parameters dvb_j_application_location_descriptor base directory base directory if set to hello the xlet will act as hello is its root directory class_path_extension an additiona classpath inside the carousel initial_class Wizard the starting class l 1 Now execute mhpconfig py to generate firstait ts and others signalling tables and execute oc update sh ocdirl 0xB 5 2003 1 2 0 0 4066 1 2 to generate ocdirl ts so you are ready to multiplex your first Single Program Transport Stream with an interactive application tscbrmuxer b 2300000 firstvideo ts b 188000 firstaudio ts b 3008 firstpat ts b 3008 firstpmt ts b 1500 firstsdt ts b 1400 firstnit ts b 1000000 ocdirl ts b 2000 firstait ts b 9772084 null ts gt myfirstfifo ts amp tsstamp myfirstfifo ts 13271000 gt mysecondfifo ts amp tsrfsend mysecondfifo ts mt OFDM mC QAM16 mG 1 4 mc 2 3 mf 578 APPLICATIONS serere pererrereresver 44 http www avalpa com Avalpa Broadcast Server user manual Now to test it proceed to the decoder tuning and select the example application Here you can see the xlet during execution Write something hi this is the open caster manual 1 2 3 6 45 http www avalpa com Avalpa Broadcast Server user manual
80. s This line enables dhcp iface ethO inet dhcp and can be replaced by a static ip address this way iface eth inet dhcp iface ethO inet static address 192 168 0 1 netmask 255 255 255 0 gateway 192 168 0 1 After the file is saved F2 then F10 you have to restart the network issuing etc init d networking restart After restarting you can just exit exit Configure multicast routing Before doing any multicast it will be necessary to set up a route for example route add net 224 0 0 0 netmask 240 0 0 0 dev eth0d 9 http www avalpa com Avalpa Broadcast Server user manual To control it run from another pc ping t 1 c 2 224 0 0 1 it should show up your local multicast capable hosts PING 224 0 0 1 224 0 0 1 56 84 bytes of data 64 bytes from 192 168 2 203 icmp_seq 1 ttl 255 time 0 822 ms 64 bytes from 192 168 2 203 icmp_seq 2 ttl 255 time 0 724 ms 224 0 0 1 ping statistics 2 packets transmitted 2 received 0 packet loss time 1000ms rtt min avg max mdev 0 724 0 773 0 822 0 049 ms 10 http www avalpa com Avalpa Broadcast Server user manual Scope of the user manual and intended audience This manual deals with the philosophy and the principles behind the server design and try to smooth the path for the user to get quickly acquainted with the tools and how they are supposed to be used and interact each other The user manual first aim is to target technicians and specialists in bro
81. s amp tsudpsend stamped ts 224 0 1 2 3 1234 13271000 In this example we assume the two streams are 2mbps for 224 0 1 1 1234 and 3mbps for 224 0 1 2 1234 tscbrmuxer will increase the bit rate to 1327100 matching a modulation scheme 83 http www avalpa com Avalpa Broadcast Server user manual If the modulator is able to add null pid is a betterto reduce the bandwidth tsudpreceive 224 0 1 1 1234 gt inputl ts amp tsudpreceive 224 0 1 2 1234 gt input2 ts amp torts inputl ts null ts gt tsoredl ts amp torts input2 ts null ts gt tsored2 ts amp tscbrmuxer b 2000000 tsoredl ts b 3000000 tsored2 ts gt muxed ts amp tspcrrestamp muxed ts 5000000 gt stamped ts amp tsudpsend stamped ts 224 0 1 2 3 1234 5000000 The obvious problem in such approach is that the if the incoming transport stream have both the same PID like the PID for the PAT the output stream will be inconsistent so it is better to replace tables for example tsudpreceive 224 0 1 1 1234 gt inputl ts amp tsudpreceive 224 0 1 2 1234 gt input2 ts amp torts inputl ts null ts gt tsoredl ts amp torts input2 ts null ts gt tsored2 ts amp tscbrmuxer b 2000000 tsoredl ts b 3000000 tsored2 ts gt muxed ts amp tsmodder muxed ts 0 pat ts gt modded ts amp tspcrrestamp modded ts 5000000 gt stamped ts amp tsudpsend stamped ts 224 0 1 2 3 1234 5000000 Real life usage require far more complex set ups but are basically using the same t
82. s are generated using count Number of samples number of channels and sample rate will tell you also how long it lasts 73 http www avalpa com Avalpa Broadcast Server user manual Audio and video real case ingestion study encoding logo_tv png Let s begin with a sequence of commands that will eventually give you some encoded files that can be used with Avalpa Broadcast Server Of course this is just an example it s better to stick with it for the beginners otherwise you are on your own wget http video blendertestbuilds de topdir ED movie only pal iso wget will download the iso of Elephant Dreams short and the following command will encode audio and video adding an external logo and enabling the initial synchronization sudo mount o loop movie_only_pal iso mnt ffmpeg vn ab 128k ar 480000 i mnt VIDEO TS VTS 01 1 VOB acodec mp2 ac 2 ed mp2 ffmpeg i mnt VIDEO TS VTS 01 1 VOB an vf movie OpenCaster tutorials encoding logo_tv png wm in wm overlay 0 0 0 0 out f mpeg2video vcodec mpeg2video b 2600k maxrate 2600k minrate 2600k bf 2 bufsize 1835008 aspect 4 3 ed m2v sudo umount mnt esvideo2pes ed m2v 1 gt ed video pes 2 gt ed pes length esaudio2pes ed mp2 1152 48000 384 1 3600 gt ed audio pes 74 http www avalpa com Avalpa Broadcast Server user manual The file ed pes length is generated by esvideo2pes and it s the length of the video in PTS ticks in this case we will get that ed
83. s were about missing EIT and TDT tables 33 http www avalpa com Avalpa Broadcast Server user manual Teletext support txt This tutorial describes support for digital teletext generation and multiplexing To describe how does teletext works and its packets layout is out of this document but we will address how teletext packets are encapsulated into transport stream Once a receiver decoded the packets has two choices not exclusive modulate the teletext signal into an analog video output and or render the teletext as on screen graphics however when the video output is HDMI the only way to support teletext for the decoder is on screen graphics because up to now HDMI is not supporting in band teletext Teletext packets are generated by pythons scripts presented later let s suppose we have some teletext packets stored in one file we will present two utilities that take care of the forthcoming process txt2pes and pesdataZ2ts txt2pes pages txt 15 3600 1800 gt txtpage pes amp Txt2pes will generate PES packets from TXT packets the first parameter 15 is how many TXT packets should be inserted in a single PES packet This information is related to the PES packet time information and also bit rate Teletext has maximum number of packet per frame that is actually split in halft per field 3600 is the number of PTS clocks for the first PES packet while 1800 is the increment of the PTS clock every PES packet 1800 is actually 50 PES p
84. sec so you can learn about presentation PTS and decoding time stamps DTS of the elementary stream of the program stream for example you can see in the above print that decode time stamp is correctly a bit earlier than presentation time stamp for the same frame The time is printed as seconds and as 90Hz clock we will discuss again PTS and DTS later on while discussing synchronization remember that pesinfo will give you the necessary information pes2es tool will allow you to extract from a program elementary stream its elementary stream The tool takes as input a program elementary stream file and a stream header id you can 64 http Www avalpa com Avalpa Broadcast Server user manual read the header id using pesinfo as just shown in the example pes2es videooutput pes 224 gt video es will extract the stream OxeO 224 that s a typical video id while typical audio id is OxcO 192 ts2pes firstaudio ts 2068 gt audiooutput pes pes2es audiooutput pes 192 gt audio es Analysing mpeg2 video files esvideoinfo first file mux The command esvideompeg2info video es will print out information from the video frames header here is a typical print of a Group Of Picture GOP eee Sequence header format 720x576 4 3 25fps bitrate 6 00Mbs vbv buffer size 112 constrained no Sequence header extension profile is Main level is Main GOP header measured size 344267 bytes bitrate from measured size
85. sel PID E Null Packets PID 8191 gt PCR Overall uiter Profile MGF3 Hz Runnings Elapsed Time 00 01 54 es as active User Level Administrator DB d Y D 5 Topology Signal Interface Monitoring Interpreter Advanced Streaming AV Decoder DVM100 Rohde amp Schwarz PCR analysis 81 http www avalpa com Avalpa Broadcast Server user manual Now another step towards a more flexible play out system what if we want to change our schedule after it started We can do that easily with some symbolic linking suppose that instead to use file names we use symbolic links Ln Ln Ln Ln Ln Ln S S S S S S ed ed ed ed ed ed audio video audio video audio pes pes pes pes pes video pes audiol videol audio2 video2 pes pes pes pes audio3 video3 pes pes pesvideo2ts 2064 25 112 2900000 1 videol pes video2 pes video3 pes gt video ts amp pesaudio2ts 2068 1152 48000 384 1 audiol pes audio2 pes audio3 pes gt audio ts amp To change a scheduled file we just need to change the symbolic link before it starts to be play rm rm Ln Ln audio2 pes video2 pes s bb audio pes audio2 pes s bb video pes video2 pes 82 http www avalpa com Avalpa Broadcast Server user manual Re multiplexing input transport streams Re multiplexing is a very common scenario in many DVB networks and can be achived for ethernet input output also w
86. ser manual Appendix C Related readings Some interesting readings from Academy related to Avalpa Broadcast Server are Open Source End 2 End DVB H Mobile TV services and network infrastructure The DVB H pilot in Denmark about how OpenCaster has been used into dvb h integration UITBOUWEN VAN EEN TESTOPSTELLING VOOR TESTEN VAN MHP FUNCTIES VOOR DIGITALE TELEVISIEONTVANGERS about how OpenCaster has been used for MHP conformance test An open source software framework for DVB transmission Acm paper presented jointly with ftw Telecommunications Research Center Vienna Vienna Austria at 16th ACM international conference on Multimedia Vancouver British Columbia Canada 87 http www avalpa com Avalpa Broadcast Server user manual Appendix D Mpeg2 transport stream overview Available from courtesy of Prof Antonio Navarro from Aveiro University 88 http www avalpa com
87. stead of NULL packets a time stamp is added at sending time and NULL packets are re generated by the receiver while analyzing RTP packets in the additional memory buffer OpenCaster tipical usage scenarios are local networks and or DVB headends so we are more concern about keep jitter and latency lower as possible than network cost that s why for now we strictly supports UDP only 29 http www avalpa com Avalpa Broadcast Server user manual Avalpa Broadcast Server for advanced datacasting EPG eit An interesting signalling is the EIT Event Information Table these tables are received by the box and used to generate the Electronic Program Guide Have a look at eitconfig py it is a template so you ll need to change the date and the time from the python config to your current time so the decoder will show the events as they are coming in a short time ee Event Information Table ETSI EN 300 468 5 2 4 eit event_information_section table_id EIT_ACTUAL_TS_PRESENT_FOLLOWING service_id avalpal_service_id transport_stream_id avalpa_transport_stream_id original_network_id avalpa_original_transport_stream_id event loop event_loop_item event_id 1 start_year 108 since 1900 start_month 6 start_day 10 start hours 0x00 use hex like decimals start_minutes 0x00 start_seconds 0x00 duration_hours 0x23 duration_minutes 0x00 duration_seconds 0x00 running status 4 service is run
88. t information insertion and generation based on Apache and MySQL check http www avalpa com assets freesoft opencaster AvalpaBroadcastWebEPGManual v1 0 pdf for its manual 6 http www avalpa com Avalpa Broadcast Server user manual 2 Hardware boards for ASI and DVB modulations for Avalpa Broadcast Server are carefully tested and choosen and their software is customized for recuded latency and improved performance Avalpa Broadcast Server generated output has been successfully integrated on top of many third parties systems among them it was already deployed with systems by Cisco Scientific Atlanta Ericsson Tandberg Eurotek Harmonic Scopus Mitan Screen Service Wellav DeltaCast Sr Systems 3 Support for installation and integration with third parties is far faster as the hardware configuration is standard Contact info avalpa com for information about system integration 7 http www avalpa com Avalpa Broadcast Server user manual Copyright and warranty OpenCaster the software OpenCaster software is Copyright C 2008 2010 by Avalpa Digital Engineering SRL OpenCaster software is free software you can redistribute it and or modify it under the terms of the GNU General Public License as published by the Free Software Foundation either version 2 of the License or at your option any later version The OpenCaster software is distributed in the hope that it will be useful but WITHOUT ANY WARRANTY without even t
89. tax indicator 1 0x01 fixed 0 0x00 reserved_1 3 0x03 Section_length 17 0x0011 Transport_Stream_ID 1 0x0001 reserved_2 3 0x03 Version_number 1 0x01 current_next_indicator 1 0x01 valid now Section number 0x00 Last Section number 0x00 Program number 1 0x0001 reserved 7 0x07 Program map PID 1031 0x0407 Program number 0x0000 reserved 7 0x07 Network PID 16 0x0010 CRC 614848810 0x24a5d92a 27 http www avalpa com Avalpa Broadcast Server user manual Transport stream bitrate start here To learn a bit rate of a transport stream file you can use tspcrmeasure in this way tspcrmeasure sample ts 4000000 Where 4000000 is your initial guess of the bit rate the tool needs a guess because it will compare the input guess value with the real bit rate giving information about the differences After the first execution you can try again with the values suggested by the tool Usually you should just verify that instant bit rate prints are quite constant that means the transport stream is not corrupted and can be processed Sometimes bit rate is not constant because null packets have been removed for storage purpose in this case null pids need to be reinserted before use For a better understanding of PCR have a look at Tektronix s A Layman s Guide to PCR Measurements A typical print of tspcrmeasure is pid 2064 new pcr is 614805912 pcr delta is 6
90. ting Understanding mpeg audio compression features is beyond our interest but to multiplex audio you will need to know some of the information printed here bit rate sampling rate and frame size Sampling rate is the number of samples present in 1 second that s why is expressed in Hz while frame size is the dimension in bytes of all the audio frame 48000 Hz is quite a common sample rate but also others are supported Knowing frame size and bit rate you can figure out how long the frame lasts and how many samples it brings with the sampler rate information Summary to analyse an audio stream from a input ts you will need the following commands ts2pes input ts audiopid gt audiooutput pes pes2es audiooutput pes stream id usually 192 gt audiooutput es esaudioinfo audiooutput es 68 http www avalpa com Avalpa Broadcast Server user manual How to encode mpeg digital video files with ffmpeg and mjtools Here is an example of video encoding done with ffmpeg ffmpeg i input ext an vcodec mpeg2video f mpeg2video b 5000k maxrate 5000k minrate 5000k bf 2 bufsize 1835008 video mp2 i input file that can be video file supported by ffmpeg decoding an no audio if audio is present in the input it will be ignored vcodec video codec mpeg2video is the video codec we are looking for mpeg2 video f output format this mpeg2video is the output file format we are looking elementary stream video b maxrate
91. ut Avalpa Broadcast Server enables you to set up a play out system of a sequence of pre encoded files the following chapters describe audio video playout system you can skip this section if you are interested in such usage This shot shows the play out system in action straight from a budget tv set hence the interlacing moire and horizontal scanline artifacts Many tv services are just the broadcasting of recorded events video and films think business television hospitality and some satellite channels This context is a perfect match for Avalpa Broadcast Server Using the following tools the broadcaster can avoid expensive real time systems greatly reducing costs parts complexity and the storage needs for the running play out system To understand the play out system is necessary to understand the tools presented in this section at the end of the chapter the simplest possible play out is realized with just a few command lines Introduction to ingestion The most important issue about the ingestion of content is to validate it before usage so in the next chapters some analysis tools are presented to make sure Avalpa Broadcast Server is filled with proper input from the encoders 62 http www avalpa com Avalpa Broadcast Server user manual Current supported input formats for playout usage are MPEG2 video MPEG2 audio Dolby Digital aka ac3 Dolby Digital Plus
92. v complaint stream will fail to be decoded correctly Vbv information is also collected in a log file vbvData dat that can be plotted with the command gnuplot plot p the plot p file is available in the directory Opencaster version tools vbv the result looks like The Y is reporting the vbv buffer fullness while X is reporting the time in frame number gnuplout let you zoom in an area using right click so you can analyse peaks and everything else 67 http www avalpa com Avalpa Broadcast Server user manual Analysing audio elementary streams esaudioinfo first file mux Avalpa Broadcast Server comes also with esaudioinfo tool to analyse mpeg audio elementary stream usage is simple esaudioinfo audio es A typical output for every audio frame is already quite verbose Fs audio header packet 1475 position 983812 audio version MPEG Version 1 ISO IEC 11172 3 audio layer Layer II protection bit Not protected bit rate index 224kbps sampling rate 48000Hz padding Frame is not padded audio frame from headers formula can have rounds 672 bytes 5376 bits channel mode Stereo copyrights Audio is not copyrighted original Original media emphasis None audio frame size from stream measured 672 bytes 5376 bits see MPEG 1 Audio Layer II is an audio codec defined by ISO IEC 11172 3 While MP3 is much more popular for PC and internet applications MP2 remains a dominant standard for audio broadcas
93. video2ts sync bb video pes new presented video frame is at 57290400 636 56 00 sec decode time stamp is at 57286800 636 5200 sec Basically the prints report about the tools closing the previous files and opening the new files however something fishy is going on because we read that bb audio pes new presented audio frame will be at 57164400 635 1600 sec bb video pes new presented video frame is at 57290400 636 5600 sec We are out of synchronization The first value is the time in PTS ticks 90 KHZ the second is the first time in seconds 57164400 90000 This problem is also signalled by a warning message 77 http www avalpa com Avalpa Broadcast Server user manual pesaudio2ts warning missed ed audio pes length file we specified that the audio file must be generally shorter than the video file however for pesaudio2ts to know about how much short it is the audio compared to the video it needs additional information files ed audio pes length bb audio pes length and bb2 audio pes length that are the same files we generated while encapsulating the video files to pes in the previous chapter so just rename them as mv bb pes length bb audio pes length mv bb2 pes length bb2 audio pes length mv ed pes length ed audio pes length and restart the whole processes after the first video you will correctly read that both pesaudio2ts and pesvideo2ts report the exact PTS that is going to be the first frame of the incoming video
94. work_information_section network_id 1 network_descriptor_loop network_descriptor network_name Avalpa linkage descriptor transport stream id original network id service id 1 linkage type 0x09 OUI loop OUI data OUI Ox15A any OUI selector bytes avalpa transport stream id avalpa original transport stream id 1 private_data_bytes U l It is also necessary to add the dsmcc descriptor to the pmt pmt program_map_section program_number avalpal_service_id PCR_PID 8191 program_info_descriptor_loop stream_loop stream_loop_item stream_type 11 data stream type 38 http www avalpa com Avalpa Broadcast Server user manual elementary_PID avalpal_dsmcc_pid element info descriptor loop stream identifier descriptor component tag dsmccB association tag 1 1 For using more advanced DVB SSU you will also need another descriptor in the pmt regarding a new table the UNT pmt program_map_section program_number avalpal_service_id PCR_PID 8191 program info descriptor loop stream loop stream loop item stream type 11 data stream type elementary PID avalpal unt pid element info descriptor loop L data broadcast id descriptor data broadcast ID 0x000A DVB SSU OUI info loop OUI info loop item OUI anyOUI update_type 0x02 with broadcasted UNT 0x01 without UNT it requires a stream_identifier_descript

open caster 2.0 user manual - Avalpa Digital Engineering Srl

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