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DOUBLETALK DEVELOPER`S TOOLS

1. Non Buffered PCM Mode The command At places DoubleTalk PC in non buffered PCM mode Note that this is similar to the Buffered PCM Mode command but the sampling rate parameter n is omitted As in buffered mode PCM data is expected to be linear eight bit signed data and the output level can be adjusted with the Volume command It is up to the application program to write the PCM data to DoubleTalk at the desired sampling rate e g for a desired sampling rate of 44 1 kHz each sample should be spaced 22 7 uS apart PCM mode is RC SYST E ES uN 38 DOUBLETALK TOOLS termina TTS por d immediately when a value of 80h 128d is written to the TTS SYNTHESIZER PROGRAMMING TIPS This section contains additional information about DoubleTalk s TTS synthesizer which is not covered in the User s Manual You will learn how to ensure DoubleTalk remains as responsive as possible a few programming tricks and how to support user exception dictionaries Response Time Considerations Considering the computations DoubleTalk has to go through to translate even the simplest word it can still be considered to be quite responsive an important requirement for visually impaired users of screen reader programs Understanding how DoubleTalk s text to speech algorithms work can help ensure that your programs will be as responsive with DoubleTalk as possible When the TT
2. DOUBLETALK DEVELOPER S TOOLS Copyright C 1992 1996 RC Systems Inc All rights reserved TABLE OF CONTENTS INTRODUCTION a ii delas 1 OVERVIEW s ent lia IA Da a AS ALA a iS A ES ed ta a 1 DESK CONTENTS iras da ia Ii A A ADE is a Ses de tate ii Manes BAS da 2 PRINTER EMULATOR a A A A a A A 4d ia 2 Tastaltirng DLERN dad AS A A AA A A 2 Disabling DoubleTalk s Buffer sence cis ns 3 Removing DTERN Erom Memory A ek ae A 3 Checking For DTERN S Presence si Me A a ee Rk oe A eee 3 sending Text and Commands e a eed censors y e cena dere Bee ee eee aw 4 Stopping Speech PrOGUCEVON es lid e eek e AS oak Mr bad 5 BASTE LIBRARY yoegan Sele fara els da a Mee da A Mee a a Sk A es eels la a da 5 CLIBRARY putoro IS E a RES A ae A AA AS A AAA 6 DATA E TEE PORMADS a VA AS sek eds DIA A A A AA a SR ve 6 EBEETLSAEOEMAE ei la sven droga a aa araa hey ie aaa la aaas a 7 PGMs Ee AR OMe ti aa oe eee val eta ses eevee talar ea 7 SOUNG conversion Utility y ia Sen s oe Pda e ee ener Bie oer es Be lt e 8 Silence threshold lts we See A w See de 9 Creating Library ILLES suo eeri ri oi ware Bare ew SOS aa Bos 9 IGN Pale cMOUMAEs rice si e ie ceded A AA ye Vie a ed 9 ASSEMBLY LANGUAGE ARD A a o ns jon a 10 PUNGCEDON Ca iS a Cie ge Ge A o a A 10 HARDWARE TO a e O o A A E a A ods 13 DoubLetalk A oe ee ee a Se ee See a eds 13 DOs BODES sects wed A wild A A
3. DATA FILE FORMATS The LPC PCM and TGN functions in the Basic and C libraries utilize a common file format for their data files If you intend to use your own data files with either library you must be sure to adhere to these formats Note that the SmartTalk program included on the Utilities disk utilizes the same formats and may be used for testing your data files RC SYST Gl MS Hb DOUBLETALK TOOLS LPC File Format The first word two bytes of an LPC data file indicates how many entries words and or phrases are contained within the file and information about the LPC data format The lower 14 bits 0 13 contain the number of entries therefore up to 16 383 words and phrases can be stored in a single LPC data file Bit 15 FMT indicates the type of LPC data stored in the file where 0 5220 format and 1 D6 format Bit 14 is reserved and should be cleared to 0 Bit 7 6 5 4 3 2 1 0 A A A A A A A E 3 NUMBER O E Be Nc To R LES 3 byte 0 A A A A A A A U 15 14 13 12 JE 10 9 8 A A A A A A A E 3 FMT 3 0 3 NUMBER O E ENTRIES 3 byte 1 A A A A A A A A U Figure 1 LPC Data File Header Following the header word is the actual LPC data in a length data format as shown below This format was chosen because it is very easy to append new entries to the file a table of pointers doesn t have to be maintained as with other formats and each entry may be u
4. EXC oddnames ODDNAMES EXS lt Enter gt onyms exc a ACRONYMS EXA test EXA onyms test a 136 DOUBLETALK TOOLS Compiling From the Command Line The compiler also supports an immediate mode of operation which compiles a single source exception on the command line This is useful in situations where only a few exceptions are needed and or the compiled output is to be hard coded into an application program COMPILE exception Example compile s a mple ae Compiler output S A MPLEey Downloading Compiled Dictionaries Downloading dictionaries which have been compiled is easy If the dictionary was compiled with the A switch your application only needs to send the object file to the synthesizer as it would normal text The LOADER BAS program is an example of how to download a standard EXS object file PCM MOD Gl In PCM mode all data sent to DoubleTalk is written directly to DoubleTalk s digital to analog converter DAC This results ina very high data rate but provides the capability of producing the highest quality speech as well as sound effects that are not possible using the other modes DoubleTalk also supports ADPCM which reduces th ffective data rate by a factor of one half to one third that of standard PCM PCM driver source code compatible with both the PC and LT can be found in the file DT_PCM ASM DoubleTalk PC supports two
5. Voice Frame Voice frames contain the duration and frequency pitch information for each voice All Voice frames are stored in a 4K buffer within DoubleTalk but are not played until the Play command is issued If the number of Voice frames exceeds 4K bytes in length DoubleTalk will automatically begin playing the data Voice frame format Voice frames Figure 6 consist of three frequency time constants K1 K3 and duration byte Kd which specifies how long the three voices are to be played The relationship between the time constant Kn and the output frequency fn is fn 16 768 Kn where fn is in Hertz and Kn 4 255 Setting Kn to zero will silence voice n during the frame The Kd parameter may be programmed to any value between 1 and 255 The larger Kd is made the longer the voices will play during the frame Table 1 greatly simplifies the task of finding Kn for a particular musical note The tone generator can cover a four octave range from C two octaves below Middle C Kn 255 to D two octaves above Middle C Kn 14 Kn values less than 14 are not recommended For xample the Voice fram DATA 24 64 0 0 will play Middle C using voice 1 K1 64 Since K2 and K3 are zero voices 2 and 3 will be silent during the frame The duration of the note is a function of both the tempo Kt and duration Kd which in this case is 24 As another example RC SYST E ES uN 2
6. To ensure the the A two ways to prevent it from occurring One way is to end each group of exceptions wit unconditional exception that matches any co n an on xampl A pronunciation r well to ensure matches only for specific characters letters or numbers If end the dictionary with the following exception RC SYST Gl 30 This technique wor such DOUBLI xception ks as certain the exception dictionary is to replace the ROM rules entirely ETALK TOOLS This special exception causes unmatched characters to simply be ignored rather than receive the pronunciation defined by the ROM rules Effect on punctuation Punctuation defined in the exception dictionary has priority over the Punctuation Filter command Any punctuation defined in the dictionary will be used regardless of the Punctuation Filter setting However if the dollar sign character is defined in the text fragment of any exception currency strings will not be read as dollars and cents Character mode exceptions The information presented thus far applies to both the Text and Character modes of DoubleTalk Character mode exceptions however can be defined independently of the Text mode exceptions or be i e ncluded as a subset of them to avoid duplicating similar xceptions The beginning of the Character mode exceptions is defined by including the character C between the last Text
7. to the right define the right context Both contexts are so an exception can contain neither either or both There are also 13 special symbols or context tokens that RC SYST Gl 27 DOUBLI ETALK TOOLS can be used in an exception s context definitions The tokens and their meanings are given in Table 3 Symbol Definition A vowel a i O U y A front vowel e i y A A consonante Dr e a Es ar Ay Tp Ky Lr my Nn Pr Gr Y Sr t V Wy X Z x One or more consonants Zero or more consonants A voiced consonant b d g J 1 m n Lr Vy W Z One Of dy dy ly Ap Xp Sy Er Zy Chy sh th Ons ofi bs Cr d EnG Pr t A suffix e s ed ly er s ely ing s ingly ement s eless eness able s must also be followed by a non alphabetic character amp Avsibilant Cy Ge Fp Sp Xp Zp Ch SH Any nonalphabetic character includes numbers spaces etc A digit 0 9 One or more digits Table 3 Context Tokens The right side of an exception P specifies the pronunciation that the text fragment is to receive consisting of zero or more valid phonemes listed in Table 5 of the DoubleTalk PC LT User s Manual If no pronunciation is given no phonemes no sound will be given to the text fragment i e the text fragment will be silent A dictionary file may also contain comments but they must be on lines by themselves i e they cannot be on the same line as an ex
8. until it receives at least one carriage return 0Dh or null 00h except when in Character mode Only the text up to that point will be spoken A special feature of DTPRN is the way in which it handles DoubleTalk commands DoubleTalk itself accepts only a control character A by default for commands which can be somewhat difficult if not impossible for a user to enter in some printing applications such as a word processor For this reason DTPRN has been written to also accept an asterisk as the command character besides th standard A character A so called asterisk command must be followed by an alphanumeric character or to be considered a valid command by DTPRN Examples of valid asterisk commands are 8s 3E 10P RC SYST E lt lt n ES DOUBLETALK TOOLS If th text being read contains as DoubleTalk s voice changing unexpectedly terisk characters you may find if the characters following an asterisk evaluate to a valid command For this reason DTPRN allows you to change its com with the optio printing character example C amp changes the command disable DTPRN s command recogniti For example DTPRN LPT1 N C installs DTPRN as LPT1 with the disabled Note that even when DTP changed or disabled using DoubleTalk s command character Stopping Speech Production Some application programs require that the speech be stopp
9. the compiler will use the source file name XS automatically The object file is the name of the compiled exception 11 be created If you do not supply a name for the and add the the COMPILE command consist of either a forward slash appear after File Types The compiler described in are shown in the file name s character followed by a letter Options can be ly in the single command line syntax and if given must supports three different output object formats this section The default object file name extensions the following table Option Switch Default Extension File Type none EXS Standard A EXA Auto load fC EXH Chained where File Type is defined as RC SYST E ES uN Standard object file Contains the compiled exceptions terminated by the EOF character 1Ch Auto load object file The structure of this file type is as follows ODh 1Eh 01h 18G 00h Olh L 00h compiled exceptions 1Ch 00h 01h U 00h The header contains all the commands necessary to begin downloading the exceptions to the synthesizer AO DOUBLETALK TOOLS Input source f the extension fo add the default automatically The following CO compile odd compile odd compile odd Object file 3 compile Source file Object file as are these compile acr Object file compile acr RC SYST E ES uN The trailing bytes immediately fo
10. DoubleTalk just as if it were a printer Built in exception dictionary support allows the pronunciation of any word or character to be changed by the programmer or end user The rich command set allows the voice output to be tailored to suit any user s taste All DoubleTalks contain a unique program readable silicon serial number This enables a program to lock itself to a specific SYST E ES uN H DOUBLETALK TOOLS DoubleTalk providing a very secure form of software protection wishes but each will still run on only one computer DISK CONTI ENTS copy A user can make as many copies of the program as he This disk contains the following programs and files TOOLS DOC This file DTPRN COM Text to speech printer emulator INT4DAPI COM IBM Speech Adapter BIOS emulator COMPILE COM Exception rule compiler DTOB LIB Basic DoubleTalk support library QB 4 5 DTOBX LIB Basic DoubleTalk support library PDS 7 x DTC LIB C DoubleTalk support library DTDECLAR BI Function sub declaration file for DTQB X LIB DTC H Function prototypes for DTC LIB DTOB_EX BAS Basic DoubleTalk library demo program DTC_EX C C DoubleTalk library demo program LOADER BAS Example Basic exception dictionary loader TXTPHM BAS Basic program referred to in DTOB_EX BAS and DTC_EX C DT_INTGT ASM Assembly language
11. Information Application Note 1 Interfacing to Other Devices Describes methods of interfacing DoubleTalk PC to devices such as radio transmitters and the telephone network Available from RC Systems Technical Support Services RC SYST 43 DOUBLETALK TOOLS E ES uN
12. PCM modes buffered and non buffered In buffered mode PCM data is queued in an internal 4096 byte circular buffer which is dialed out to the DAC at a programmed sampling rate DoubleTalk PC s TTS port status flags are constantly updated in this mode and I O transfer is performed using the usual handshaking RDY method The maximum sampling rate supported in buffered mode is 11 kHz Both DoubleTalk PC and LT support this mode In non buffered mode PCM data is sent directly to the DAC in real time The TTS port status flags are meaningless in this mode the maximum sampling rate is better than 48 kHz Only DoubleTalk PC supports non buffered mod Buffered PCM Mode The command Ant places DoubleTalk in the Buffered PCM mode All subsequent data sent to DoubleTalk is then routed to the DAC buffer RC SYST STS DOUBLETALK TOOLS E ES uN Because the PCM data is buffered within DoubleTalk the output sampling rate is independent of the data rate into DoubleTalk as long as the input data rate is equal to or greater than the sampling rate The sampling rate can be programmed to virtually any rate between 4 and 11 kHz with the PCM Mode command The relationship between the command parameter n and the sampling rate fs is n 155 617 fs fs 617 155 n where fs is measured in kHz The range of n is 0 99 hence fs can range from 4 to 11 kHz The procedure for sending PCM data to DoubleTalk is
13. RC SYST E ES uN 13 5 DOUBLETALK TOOLS decoding table will be used by the hardware 5220 or D6 as well as the speech rate The four Speak commands are Cmd Format Speed 60h 5220 normal 64h 5220 fast 20h D6 normal 24h D6 fast Reading the LPC port yields the following status information Bit 7 6 J 4 3 2 I 0 A A A A A A A VTS A Ie et BE MUA eS My eas A Se 8 A A A A A A A A Figure 3 LPC Port Status Flags Bit 7 TS Talk Status When set to 1 indicates the LPC synthesizer is producing speech Bit 6 BL Buffer Low When set to 1 indicates that the hardware LPC data buffer has less than 30 bytes remaining Total internal buffer size 4096 bytes Bit 5 BE Buffer Empty When set to 1 indicates that the LPC data buffer ran out of data error condition if TS is also Le Bits Reserved 4 0 The TS bit can be used to effectively disable the internal hardware LPC buffer by waiting for it to drop to 0 before returning to the application program he LPC repeat function is invoked by issuing the Speak command by tself without any LPC data The command used does not necessarily ave to be the same as that used originally although the data ormat 5220 or D6 must be the same For example a program may use he fast speed 64h normally and upon the user s request repeat he last word or phrase at normal speed 60h tt hp HH See the DT_LPC ASM file for a wor
14. all punctuation be sent with the text The latency time of an initial phrase with the punctuation left in it will be much less than that of the same phrase with the punctuation stripped out of it Most screen reader programs do not send the actual punctuation to the synthesizer but send the spelling instead period comma etc If your program falls into this category try adding the actual punctuation to the end of the word period comma This will make the speech more responsive as well as give the added RC SYST Gl MS me BOS DOUBLETALK TOOLS Creating Pauses in Speech benefit of more natural sounding intonation as the text is read by the synthesizer punctuation directly affects the inflection contours If your program waits until the current phrase has been completely spoken before sending the next phrase try using the SYNC2 status flag instead of SYNC see Hardware 1 0 TTS Port above This will help increase the responsiveness by as much as 50 depending on the speed and other factors After all this talk about avoiding pauses why would one want to create them On xample is for creating the natural pauses a human reader places between paragraphs of a passage Another would be for creating emphasis at a particular point in a sentence to help enhance its meaning There are at least two ways to add pauses in your text The easiest way fo
15. command to send an index marker to either DoubleTal here n is an ASCIT number between 0 and 99 arkers may be active at any given ncrementing markers betw his is to use DoubleTalk s Thus If your progra a simple way to time marker When the cou up to a marker it Note that this value not an ASCII number This allows the mar non speaking bookmarks that are used to monitor a program can tell where oubleTalk is speaking within a passage of text k is AnI up to 100 unique m uses implement by nt reaches nd to 0 and start over again transmits the is a as was used ker to be DoubleTal i transmitted as a one byte value T w he actual method of transmission and how markers ar is here the two DoubleTalks part ways received k PC DoubleTalk PC transmits index markers through its LPC port As long as the LPC synthesizer is idle the value at the port will be 7Fh If an index marker comes in however the port s value will change to a value between 0 and 63h 0 99d and will not change until another marker comes which will overwrite the previous one f you use only one marker value in your program the value FFh hould be written to the LPC port each time a new marker is read his clears the marker to 7Fh enabling your program to detect hen a new marker comes in If you use more than one marker value uch as two alternating values this step would not be neces
16. in close the window The following exception changes the way the s will sound DCLOSE K L OW S Note the Control D character D in the text fragment Although a non printing character would any printing charact pronounced with the s rece in the text stream Plain unaffected the s will stil the translation a lgorithms t er Thus the s iving the s sound where close without the Contr l receive the z sound I matter where you place the you use it the same way in non printing character ex Foreign languages Dictionaries can be create foreign languages that is required is a high and a bit of patience If you re interested in chec foreign language dictionar which make it easy to tran exception form The Spanis using this method Language translatio language text in English this can be done with thre GRANDE L AA R J BIEN F AY N USTED YY UW The sense of translation c LARGE G RAND El FINE B I El N YOU U S T EI DH RC SYSTEMS It s not Control character in the your application s text cept LF and CR in this ma d that enable DoubleTalk t t as difficult as it may f school level foreign lang you don t have a book for k your local library Most les that include pronuncia reat it as they tring D close will be ver it appears ol D will be t does not word as long as You may use any nner o speak in ir
17. internal operating parameters in AnG The number is calculated by O shown below tware synchronization with Sync2 timing restrictions in the way parameters can be combi Can enable software and or hardware synchroniza where n is an ASCII decimal number Ring together the For example the command 9G There are no for example you or disable both ned Eon of them Note that bits 4 and 5 are the only bits that have any meaning to DoubleTalk PC 2G is the default setting Bit 7 6 5 4 3 2 1 0 A A A A A A A 3 O 3 Oe lt 8 VOY Bs OZE 07I S O71 3 OSL lt 3 COL A A A A A A A A U 3 3 K 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 DtmfDur U gt i 3 3 i 3 3 3 3 3 HiAscEn U A 3 3 3 3 3 3 3 Sync2En U 3 3 3 3 3 3 DsrEn U 3 3 3 3 HSyncEn U 3 SSyncEn U Figure 5 Protocol Options Control Bits The control bits are defined as follows Bits Reserved write 0 to ensure future compatibility 7 6 Bit 5 DtmfDur DTMF Duration Selects DTMF Touch Tone generator burst duration n command When set to 1 tone bursts will be 500 ms duration instead of 100 ms Default 100 ms 0 Bit 4 HiAscEn High ASCII Enable When set to 1 nables extended ASCII character set 128d 255d recognition Generally RC SYSTEMS do DOUBLETALK TOOLS BLEFS Bit 2 Bit 1 Bit 0 used only in conjunction with an exception dictionary for a foreign language When disabled the high order bit of all ASCII tex
18. is calculated as follows Td Kd x 256 fs sec where 0 Kd 255 Substituting the relationship fs 617 155 n into the above equation Td Kd x 155 n 2410 sec Setting Kd 1 yields the shortest duration Kd 0 treated as 256 the longest Depending on the value of n Td can range from 23 ms to 16 5 sec The tone frequencies Fl and F2 are computed as follows Fn Kn x fs 1024 Hz where 0 Kn 255 Substituting the relationship fs 617 155 n into this equation Fn Kn x 603 155 n Hz Depending on the value of n Fn can range from 0 Hz to 2746 Hz If only one tone is to be generated the other tone frequency may be set to 0 Kn 0 or equal in frequency Note however that due to the additive nature of the tone generators the output amplitude from both generators running at the same frequency will be twice that of just one generator running Both K1 and K2 may be set to 0 to generate silenc Note that the frequency step size and frequency range are strictly functions of n In general the larger n is the larger the step size and range will be The parameter Kn can be thought of as a multiplier which when multiplied by the step size yields the output frequency For example setting n 95 corresponding to an internal sampling rate of 10 28 kHz results in a frequency step size of 603 155 95 Hz or 10 Hz Thus the output frequency range spans 0 Hz to 255 x 10 Hz or 2
19. mand character to any other nal Cx command line switch haracter from to amp To n altogether use C by itself For el O buffer and command recognition both RN s command character has been commands can still be issued to DoubleTalk A buffer has been spoken This can writing a X 18h to DoubleTalk causes speech production to stop cleared The syn appropriate BIOS Initialize funct toc int 170 T left and right Shif he user may al DoubleTalk s current above methods Note output to DoubleTal without performing handshaking of to be stopped even if the input b settings are BASIC LIBRARY It is recommended that the k s TTS port direc such as screen readers for the blind may d befor verything in the input be done quit asily by simply s TTS port which immediately and the entire input buffer to be thesizer can also be stopped by using the ion call AH 0 for int 14h or AH so stop the speech by pressing both keys simultaneously not be affected by any of the X character be tly using an OUT instruction any kind This allows the speech uffer is fulls The Basic library routines suppli ed on this disk provide support for using DoubleTalk with Microsoft QuickBASIC and Professional Basic Pek disk In fact was written in QuickBASIC 4 Fully documented Basic source code de function is included in the file The routines included in th
20. s input buffer LPC Speaks one or more words from an LPC data file LPCBUFON Enables the LPC synthesizer s input buffer LPCBUFOFF Disables the LPC synthesizer s input buffer LPCSPD Controls the LPC synthesizer s output speed LPCRPT Repeats the last LPC word or phrase PCM Plays one or more sounds from a PCM ADPCM data file PCMRATE Controls the PCM playback speed TONES Plays back a TGN data file proprietary format TONES1 Plays back a TGN data file standard format C LIBRARY The C function library provides a set of C functions similar to the Basic library Fully documented C source code demonstrating each function s use is included in the file DTC_EX C The following is a list of the functions provided in the DTC LIB library DT_Init Locates and initializes DoubleTalk DT_RomVer Returns DoubleTalk s ROM version number DT_SerNum Returns DoubleTalk s serial number DT_Sts Returns the status of the TTS and LPC synthesizers DT_Intgt Returns the current settings of the TTS synthesizer DT_Say Speaks a text string through the TTS synthesizer DT_X1t Converts a text string to a phoneme string DT_Lpc Speaks one or more words from an LPC data file DT_LpcRpt Repeats the last LPC word or phrase DT_Pcm Plays one or more sounds from a PCM ADPCM data file DT_Tgn Plays back a TGN data file proprietary format DT_Tgnl Plays back a TGN data file standard format
21. 2 DOUBLETALK TOOLS DATA 48 64 51 43 plays a C E G chord for a duration twice as long as the previous example Note Kn Note Kn 255 FFh D 57 39h E 241 F1h D 54 36h D 228 E4h E 51 33h D 215 D7h F 48 30h E 203 CBh F 45 2Dh F 192 COh G 43 2Bh F 181 B5h G 40 28h G 171 ABh A 38 26h G 161 Alh A 36 24h A 152 98h B 34 22h A 144 90h 32 20h B 136 88h 30 1Eh E 128 80h D 28 1Ch E 121 79h D 27 1Bh D 114 72h E 2 5 le Oh D 107 6Bh F 24 18h E 101 65h F 23 17h F 96 60h G 21 15h F 90 5Ah G 20 14h G 85 95h A 19 13h G 81 51h A 18 12h A 76 4Ch B 17 11h A 72 48h C 16 10h B 68 44h C 15 OFh C Mid 64 40h D 14 OEh C 60 3Ch Table 1 Musical Pitch Kn Values Choosing note durations and tempo Table 2 lists suggested Kd values for each of the standard musical note durations This convention permits shorter 1 64th note and intermediate note values to be played while maintaining the same degree of accuracy This is important when for example a thirty second note is to be played staccato or a note is dotted multiplying its length by 1 5 Using the suggested values it turns out that most musical scores sound best when played at a tempo of 255 or faster i e Kth 0 Of course the right tempo is the one that sounds the best RC SYST a De DOUBLETALK TOOLS
22. 550 Hz in 10 Hz steps As an example suppose an application needed to generate the ton pair 440 350 Hz a dial tone for say 2 5 seconds We will arbitrarily choose n 95 The tone duration parameter Kd is calculated as follows Kd 2410 x Td 155 n substituting Td 2 5 sec and n 95 Kd 2410 x 2 5 155 95 100 K1 440 Hz is computed follows K1 Fl x 155 n 603 440 x 155 95 603 44 In like manner K2 350 Hz is computed to be 35 RC SYST AS DOUBLETALK TOOLS E ES uN In order to embed the command in a text file are converted to their ASCII equivalents 100 35 14 The complete command becomes the computed values d 44 hoy ana T A95Jd hich can be embedded within normal text for the TTS synthesizer EXCEPTION DICTIONARI a S Exception dictionaries make it possible to alter the way the TTS synthesizer speaks any string of characters This is useful for correcting mispronounced words or even speaking foreign languages This section describes how to create exception dictionaries for DoubleTalk he Text a OM based he host i nd Character modes of the TTS synthesizer rely on a set of English pronunciation rules for converting text sent from nto speech These rules determine which sounds or honemes each character will receive The position of each letter n a word as well as its context is consid
23. AA IA A AAA AS AAA 13 DPC PORC AS A A Be ed ee we AAA E A AAA 13 TES POLE emir ia e Ey hed bee eee WES Bs 14 Doublelalk LI Dt a ke ee deh wee sa es Ba ie A ee ea eS le ee Re AS 16 Reading Che TS SYNG El ti Sie ee A waa lees Be Dw 16 Protocol Options command si ii da 17 Detecting DOUBTS Tad miee spree is a Sa Gk We A A ag 18 Indexing ei A A A AS AAN E AAA e 19 DOublelalk BE Seurasta ara la a a a Se ate le aaa n 19 Double Tak LT sis Spots ovals cates Space 2 lia auayey s Sees wi aieyd wees ieseels 19 Not all DoubleTalks support indexing 20 Interrogating Dou bleTark sack gerd it eee awk amp ered s iras Be 20 MUSTCAL TONE GENERATOR iii A A a A e ied Sema 21 Tattialize Command sa eae A a ae a 21 InTtializ command format mres See eea A ees amp ee Se ete a 22 VOICE Frame 6 5 dees e ek Bite Sev gw E Ae Ate SS ASA hE So inte ee 22 Voice frame format dio Oe esse et bag yta bos othe etn 22 Choosing note durations and tempo ooooooooooo oo ee ee eee 23 Play Command o isis aise E wii heen Sow ati Iain Lees AS la BOSS 24 Qurt COMMAS A Sih Ee te atte Sah de ce Sec tee E ake ye ta nae ade Selecteer E E 24 Beamplte MUS A Sens de cd ence SRS Ee ae tae a BEE E 24 SINUSOTDAL TONE GENERATOR stre estes alo a a Braye here ee tals ale oS aaa aaa aos 25 EXCEP TTON DEIECITONARLDES Lorca aii De eee
24. COPY command For example to combine the files filel file2 and file3 into a single file file4 type COPY b hdr filel file2 file3 file4 The hdr file is a two byte header template supplied on this disk used for reserving room in the target file for the header required by the libraries TGN File Format There are actually two TGN file formats the simplest of which will be discussed here This format is supported by the Basic library TONES1 and C library DT_Tgnl functions The more complex proprietary format is supported by the TONES and DT_Tgn functions and is used primarily for playing full length songs SmartTalk does not use or support the use of the simpler format discussed here The first two bytes of a TGN file indicate how many Voice frames not bytes are contained within the file see Musical Tone Generator below for a discussion of tone generator Voice frames T f his value must be an integer between 0 and 16 383 The actual Voice rame data immediately follows these two bytes A TGN data file contains no amplitude or tempo information these values are passed by the calling program to the TGN functions as parameters DOUBLETALK TOOLS E ES uN o RC SYST As an example suppose a short tune consisted of 12 voice frames The first word in the TGN file would be set to a value of 12 because there are 12 Voice frames followed by 48 bytes 12
25. E ES uN Note Duration Kd Whole 192 COh Half 96 60h Quarter 48 30h Eighth 24 18h Sixteenth 12 OCh Thirty second 6 06h Table 2 Duration Kd Values Play Command The Play command causes the voice data in the buffer to begin playing Additional to DoubleTalk while the ton SYNC flag is set during this time to the playing of the tone data SYNC the data has been played Initialize commands and Voice frames may be sent generator is operating enabling the host to synchronize DoubleTalk s returns to zero after all of Quit Command The Quit command marks the end of the tone data in the input buffer DoubleTalk will play the contents of the buffer up to the Quit command then return to the text to speech mode that was in effect when the tone generator was activated Once the Quit command has been issued DoubleTalk will not accept any more data until the entire buffer has been played E xample Tune Listing 1 is a simple Basic program which reads tone generator data from a list of DATA statements and LPRINTs each value to DoubleTalk The program assumes that the DTPRN printer emulator has been installed as port LPT1 see Printer Emulator above 100 REM tone generator demo 110 LPRINT CHRS 1 J REM activate tone generator 120 READ BO B1 B2 B3 REM read a frame 4 bytes 130 LPRINT CHRS BO CHRS B1 CHRS B2 CHR B3 140 I
26. F BO B1 B2 B3 gt 0 THEN 120 REM loop until Quit 150 END 160 RO 180 REM data tables 190 200 RE Init volume 255 tempo 86 210 DATA 0 255 86 0 220 230 REM Voice data 240 DATA 46 48 64 192 2 0 64 192 48 48 0 0 48 40 0 0 48 36 0 0 250 DATA 94 24 34 0 2 24 0 0 24 0 36 0 24 0 40 0 48 0 48 0 260 DATA 48 40 0 192 46 36 0 0 2 0 0 0 48 36 0 0 48 24 34 0 RC SYSTEMS 24 DOUBLETALK TOOLS 270 DATA 46 24 34 0 2 0 34 0 46 24 34 0 2 24 0 0 24 0 36 0 280 DATA 24 0 40 0 48 0 48 0 290 300 REM Play Quit 310 DATA 0 0 1 1 0 0 0 0 Listing 1 Example Tone Generator Program The astute reader may have noticed some non standard note durations according to Table 2 in the DATA statements such as the first two Voice frames in line 240 According to the original music some voices were not to be played as long as the others during the beat The F C F notes in the first frame are held for 46 counts while the low F and C in the second frame are held for two additional counts Adding the duration first and fifth bytes together the low F and C do indeed add up to 48 counts 46 2 which is the duration of a quarter note SINUSOIDAL TONE GENERATOR The musical tone generator is capable of producing three tones simultaneously and works well in applications which require neither precise frequencies nor a pure clean output The output is a pulse train rich in harmo
27. S SYNTHESIZER PROGRAMMING TELS a AN ON Je ed eto os Ma eS 39 Response Time Considerations ra wy ae Ge eee aes et ee eS 39 Creating Pauses in Speech so sii sh clade See bold Yee ew BSG BA SS eS 40 Forcing Character ProOnunClatioM exa dite Mere Bak ced a bS 40 Supporting User Dictionaries 6 4 4 sew ORs oe narra 41 APPENDIX Atras as A ai 42 LPC Speech Encoding Services tt i 42 POP TIN Ts Dot Me Se DS E RAS II ASE E RD Me Bing EA E AAA E 43 Additional Informacion at ae ae a tes tle oe a ate a 5 43 ii IN OV RC TRODUCTION This disk comprises the Developer s Tools for the DoubleTalk PC and DoubleTalk LT voice synthesizers The information presented here along with the accompanying support files are intended to augment the DoubleTalk PC LT User s Manual that comes with DoubleTalk not as a replacement for it For example the command set for controlling the text to speech synthesizer is presented in the User s Manual and hence is not duplicated here If you cannot find the answer to a nagging problem or question you have about DoubleTalk please give our tech support people a call They d be happy to help you solve your unsolved mysteries ERVIEW DoubleTalk PC is an internal voice synthesizer for the IBM PC XT AT PS2 25 30 and compatible computers while DoubleTalk LT is an external serial driven version which can be used with virtually any platform Both contain four voice synth
28. S synthesizer receives text from an application program it queues up the characters in an internal 2 5K buffer less if an exception dictionary is loaded Assuming the synthesizer is not already talking the TTS algorithms wait until a carriage return or null is received defining what we shall call a synthesizer phrase boundary before translation into speech begins This is not true of Character mode translation begins immediately upon receipt of the first character Speaking from a cold start is the worst case scenario for the TTS synthesizer because it must translate a relatively large chunk of text before it can begin speaking Once it has begun talking however it will continue to accept and store more phrases and preprocess them ahead of the speech so the next phrase is already translated once the speech has caught up to it It is the initial phrase latency time that concerns blind users because they like the speech to begin as soon as possible upon giving the command Normally written text generally contains one or more punctuation marks such as commas and or periods In terms of human speech these marks indicate where a natural pause is to be placed DoubleTalk takes advantage of this fact by translating text in its buffer in punctuation delimited segments as defined by the punctuation boundaries which may or may not occur at synthesizer phrase boundaries For this reason it is important that
29. T DoubleTalk LT operates from a serial port at 9600 baud 8 data bits 1 stop bit and no parity 9600 N 8 1 All DoubleTalk functions must be carried out through this port there are no LPC or TTS ports to perform low level I O through DoubleTalk LT indicates when it is ready for data using the DTR hardware handshake protocol Text commands and PCM TGN data are sent to DoubleTalk by simply writing them to the serial port s transmit register The source code in the DT_TTS ASM file provide examples of how to communicate with DoubleTalk LT at the register level Using DoubleTalk LT s LPC synthesizer is quite different than DoubleTalk PC s This is because the LT emulates several of the external Echo synthesizers for compatibility with the Apple II and Macintosh platforms for which the LT was originally designed LPC driver source code compatible with both the PC and LT can be found in the file DT_LPC ASM PCM mode with the LT is a bit convoluted because at a sampling rate of 8 kHz 64 kbps it would require more than eight seconds at 9600 baud to transmit each second s worth of speech The data transfer rate problem is overcome by automatically kicking the baud rate up to 115 200 baud while in the PCM ADPCM modes If you need to support the LPC and or PCM modes of both DoubleTalks you may save yourself a lot of time by using the INT4DAPI driver described elsewhere This driver takes care of all the det
30. ails of finding DoubleTalk getting data to it ADPCM decoding etc The Basic and C libraries DTQB LIB DTQBX LIB and DTC LIB take care of the housekeeping for you as well in the Basic and C environments If you really must see PCM source code s the file DT_PCM ASM on this disk Reading the LT s SYNC flag DoubleTalk PC has a convenient means of detecting when it is talking see I O Ports TTS Port above for a description of its two SYNC flags DoubleTalk LT conveys this information in two ways one using a COM port status bit the hardware method the other utilizing a sort of software handshake protocol The Protocol Options command described below determines which method will be used The hardware sync method is usually the easiest to implement and is therefore the recommended method to use The LT s syne information is carried on the serial port s RI Ring Indicator line and will RC SYST 16 DOUBLETALK TOOLS E ES uN r f Pro T D b i e ead zero 0 when SYNC is ragment illustrates this mov dx TTS_Port add dx 6 in al dx test al 40h JZ Talking jnz Silent tocol Options command oubleTalk The command is etween 0 and 63 ndividual control bits nables sof true active The following code LT s COM port base address Modem Status Register read status test RI SYNC zf 1 if SYNC 1 zf 0 if SYNC 0 his command controls several
31. al playback rate in the libraries it is for informational use only the library PCM functions explicitly set the playback rate The high order bit FMT should be 0 if the file contains linear PCM data otherwise it should be set to 1 for ADPCM compressed data This flag is very important as it is responsible for invoking the correct decoding algorithm in the libraries The PCM file format is summarized below bytes 0 1 file header bytes 2 4 length of first entry first entry s da length of entry entry n s data The PCM files supplied on the U disks use this format Sound conversion utility ta tilities and Developer s Tools and can be examined using DEBUG CONVERT COM is a DOS based utility program used for converting eight bit VOC ou Soundblaster PCM format used in the DoubleTalk program are ADPCM compression algorithms storage requirements of sound files by a factor of two or more tput of the utility is a file containing the converted PCM ADPCM and WAV Windows libraries data used by t The utili CONVERT lt filename gt RC SYST Gl accompanied by a three byte data length header he Basic and C libraries C Sn sound file s to the Integrated into the the DOUBLI used for reducing the The format ty is run by typing the following on the DOS command line ETALK TOOLS where lt filename gt is the name of the file
32. and consequently the exception never gets a s If you suspect that this may be happening with one exceptions include more of the left hand side of t text fragment in th xample abov E EXC ng example illustrates how this can nes the o in the word process to have sound the way it is pronounced in many parts of therwise pronounced correctly the o take on the new h looks something nstead of only fragment PRO is h the initial hot at the o of your he word in the PRO P R OW would work EPTION COMPILER The COMPILE COM program is used to compile exceptio n dictionaries for DoubleTalk s TTS synthesizer Since the input compiler is and must be a plain ASCII text file dictionaries can be written and edited with any wor text editor such as DOS 5 0 s EDIT program E You can compile exception dictionaries in either of ways RC SYSTEMS 34 source to the exception d processor or the following DOUBLETALK TOOLS 1 Type all syntax COMPILE 2 Or type COMP ILI Gl and respond Source Object The source f dictionary file that wi object file extension E Options for or dash specified on the information on the command line using the following sourcefile objectfile options to the following prompts file EXC file source EXS ile is the ASCII text file containing your exception
33. ception Comment lines begin with a semicolon character so that the compiler will know to skip over it An example of an exception is C O N AA which states that o after c and before n gets the pronunciation AA the o sound in cot For example the o in conference economy and icon would be pronounced according to this exception Another example is R H This exception states that h after initial r is silent as in the word rhyme the context token represents any non alphabetic character such as a space between words see Table 3 Punctuation numbers and most other characters can be redefined with exceptions as well RC SYST Gl MS AS DOUBLETALK TOOLS 5 S I NGKO Spanish five CHR K EH R IX K T ER Basic function Note that although these examples do not contain any context definitions parentheses are still used around the text fragments The Translation Algorithm DoubleTalk s text to speech algorithm works much like the human brain does when reading printed text The algorithm scans input text from left to right and for each character scanned sequentially searches a list of pronunciation rules until it finds one that matches the character in the correct position and context When a matching rule is found the algorithm passes over the input h characters bracketed in the rule the text fragment and assigns the pronunciation given by the right side of the rul
34. command frames known as Initialize Voice Play and Quit With these the programmer can control the volume duration and frequency of each of the thr voices Initialize Command The Initialize command sets up the tone generator s amplitude and tempo speed The host must issue this command to initialize the tone generator before sending any Voice frames The Initialize command may however be issued anytime afterward to change the volume or tempo on the fly Byte 0 1 2 3 A A A A A A 3 3 0 3 Ka 2 Kelas Kth A Kd 3 Kl 3 K2 3 K3 A A A A U A A A A U Initialize command Voice frame U A A A E A A A 3 0 3 0 3 1 3 1 3 3 0 3 0 3 0 3 0 3 A A A A U A A A A U Play command Quit command Figure 6 Tone Generator Command Formats RC SYST Gl MS AS DOUBLETALK TOOLS Initialize command format The Initialize command consists of a byte of zero and three parameters Figure 6 The parameters are defined as follows Ka Voice amplitude 1 255 Ktl Tempo low byte 0 255 Kth Tempo high byte 0 255 The overall range of the tempo Kt Ktl and Kth is 1 65 535 1 FFFFh the larger the value the slower the overall speed of play The amplitude and tempo affect all three voices and stay in effect until another Initialize command is issued If the command is issued between Voice frames to change the volume or tempo on the fly only Voice frames following the command will be affected
35. d as LPT2 by typing RC SYST Gl DOUBLI For ETALK TOOLS Removing DTPRN LPT2 If no port specification is given LPT3 Duri i ng or LPT2 DTPRN wil l install itself as nstallation DTPRN will DoubleTalk serial por the user supplied o DoubleTalk DoubleTalk with the i simply tur If an error occurs during t nvalid port name or is returned in the AL regis batch program using the IF ef ani can be tak returned b OB WNR OO During operation interrupt vector if t D Note r LT BO nter ning en y DT DTPRN was successfully installed n the DoubleTal TPRN will abort the ins that DIPRN as well as Utilities a first before This sche nal DoubleTalk PC w the LT s power off scanning he ins ter This code ca ERRORLEV The following is a su PRN mmary of DTPRN is already resident An i Too Inco Doub many or invalid parameter s mpatible version of DOS leTalk could not be located tallation of DTPRN DTPRN is already resident EL command nvalid port name was specified DTPRN still loads must be 2 0 or later such no errors locate and initialize k cannot be located in the computer or ona tallation process and notify all other software drivers nd Developer s Tools disks the internal slots for me enables an application program to work hen an LT is also pr
36. dt Heel ee ets id tejas Be 27 Exception YALE AA gaa eee Se eae Be 27 The Translation ATGOPTEAM ice sete aeei Hard Mate Dyke ed Oe EE ee Bs 29 Raile precedente Y Dato at ao Mieke BRS eee ai Braud allots eau wee ars 29 Text not matched by the dictionary o oooooooooooooooooooooo 30 Effect On PUNCEUACTONE is aini adic a add A es Siete O edits Siena 31 Character mode exceptions wise A Se PS A GEES SL Applications eri e A A A A AA A a 31 Correcting mispronounced Words wea Mie elie aay oo Se be Bee ee 31 N cussing PLEASEN si A A Saye eS 32 When 05 LES NOE ZOHO Aes ecg eel we alee See are ee Sere SAE Se Grier 32 Arithmetic Gperat rS ac das Gt wie Were Oe ee AS amp ce A 32 Acronyms and abbreviations i e086 rsss eat ui riae urea a Be 32 Het e CONYIAS aeae whe we hia Wie ee Die AY Nee Bs Rapti ale Sue Seeds AS AA aon ee aa 33 Foreign languages lene sa Erag a ie oe eles ed LOS ois aD rg aloe SUE ee ays how BOE eRe 33 Language trans Tall ir Wee te eae Se heehee A Se Steere Sah tae 33 LS A A A A E A wha E ae Lag E N ah age S 34 ExCeption anomalies asein CES e EE eter a ie 34 EXCEPTION COMP TELER om ts he e ana is a ti 6 te 0 Si da dt id 34 HILLS Types in a AS AS A AS td eB 35 Compiting Erom the Command Line chew naaa dla See alee BS 37 Downloading Compiled Dictionaries m rito 37 PCM MODE Has A E A eid A ES ANS ee Syd Sow Boo anes 37 But tSredBEMMOdS Hi A AA O a a 3 N n BuBferedaBEMMOde see A A A Ea a Sieh teeta 38 TT
37. e Basi be as granular as possible This for example only the DTINIT and modules associated with initializ i the SmartTalk demo program supplied on the Utilities nd linked with this library monstrating each library DTOB_EX BAS 5 a nd C libraries were written to s that a Basic program using SAY functions will pull in only the ing DoubleTalk and using the TTS c a mean synthesizer from the library duri as those associated with LPC and in the final executable file versio Two functionally identical included DTOB LIB for use with QB 4 5 the only difference in the two libraries deals with far string 7 X RC SYST Gl saving bo ng linking Unneeded modules such PCM support will not be included th disk space and memory ns of the Basic library are and DTQBX LIB for Basic PDS DOUBLETALK TOOLS support The following is a list of the functions provided in these libraries DTINIT Locates and initializes DoubleTalk ROMVERS Returns DoubleTalk s ROM version number SERNUM Returns DoubleTalk s serial number DTSTS Returns the status of the TTS and LPC synthesizers INTGT Returns the current settings of the TTS synthesizer SAY Speaks a text string through the TTS synthesizer XLTS Converts a text string to a phoneme string TTSBUFON Enables the TTS synthesizer s input buffer TTSBUFOFF Disables the TTS synthesizer
38. e to it Scanning then resumes with the next character of text As an illustration of how the translation algorithm works let s see how it would translate the word receive using the ROM based Text mode pronunciation rules The algorithm begins scanning at the letter r and searches the R pronunciation rules for a match The first rule that matches is S RE R IH because the r in receive is an initial r and is followed by an e a consonant c and a vowel e Consequently the text fragment re receives the pronunciation R IH and the scan moves past re to the next character reCeive E is not the next scan character because it occurred inside the parentheses with the r the fragment re as a whole gets the pronunciation R IH The first match among the C rules is C S because c is followed by an e i or y C thus receives the pronunciation S and processing continues with the second e recEiv EI IY is the first rule to match the second e so ei receives th sound IY Scanning resumes at the character receiVe which matches only the default V rule V V The final e matches the rule E which applies when e is final and proceeds zero or more consonants and a vowel Consequently e receives no sound and scanning continues with the following word or punctuation if any Thus th ntire phoneme string for the word receive is R IHS IY V which is the correc
39. eTalks enables a program to leTalk anytim The values returned in order as follows Fh string terminated by CR Character 1 Phoneme 2 Text ption dictionary loaded 0 ption dictionary enabled 0 s truncated remaining for text on of dictionary size and RAM chip 2K 0 DOUBLETALK TOOLS Reverb byte nR 0 9 nd of block byte 7Fh value indicating end of parameter block E The number of parameters could change in the future so it is recommended that the End of Block byte 7Fh be used for determining when all of the data has been read from DoubleTalk The file DT_INTGT ASM shows how to interrogate DoubleTalk from assembly language programs The supplied Basic and C libraries also have their own equivalent interrogation functions built in MUSICAL TONE GENERATOR DoubleTalk contains a three voice musical tone generator which can be used for creating music and sound effects This section explains how to program the generator DoubleTalk also contains a sinusoidal generator which is covered in the next section The musical tone generator is activated with the AJ command Once activated all data output to DoubleTalk is directed to the tone generator Note DoubleTalk assumes that tone generator data will immediately follow the AJ command therefore do not terminate the command with a carriage return or null The tone generator is controlled by four four byte data and
40. ered by each rule DoubleTalk analyzes text in its input buffer by applying these rules to each word or character depending on the translation mode in use Exception dictionaries augment this process by defining exceptions or even replacing the ROM based rules T R P Exception dictionaries can be created and edited with word processors or editors that store documents as standard text ASCII files However the text file must be compiled into the internal format used by DoubleTalk before it can be loaded using the COMPILE COM program included on the Developer s Tools disk Exception Syntax Exceptions have the general form L F R P which mea right con exception ns the text fragment F occurring with left context L and text R gets the pronunciation P All three parts of the to the left of the equality sign must be satisfied before the text fragment will receive the pronunciation given by the right side of the exception Exceptions are always terminated by a carriage return character The text fragment defines the characters that are to be translated by the exception and may consist of any combination of letters numbers and symbols The text fragment must always be contained within parentheses Characters to t what must characters optional contexts he left of the text fragment specify the left context come before the text fragment in the input string and
41. esent looks for by as the use an error code n be processed ina so appropriate action the return codes DTPRN intercepts the appropriate BIOS software 14h for COM ports or 17h for LPT ports Programs that bypass the BIOS hooks by accessing the port s hardware directly as some terminal programs do never rec iv th The optional com text buffe importa while t Es Y nt that E from the screen dictionary to DoubleTalk via DTPRN he dictionary is being output to DoubleTalk output characters Disabling DoubleTalk s Buffer his can be beneficial will not speak Note DTPRN From Memory since DoubleTalk will mand line switch N is used to disable DoubleTalk s in applications where it is he voice stay synchronized with th DTPRN can be removed from memory and the interrupt vector below DTPRN restored R Checking For DIPRN s Presence to its previous state by typing text being read If your application sends an exception the buffer must be enabled discussed An application program can check for the presence of DTPRN by exa 0 5Eh int 17h RC SYSTEMS mining the interrupt vectors The word at segment wher specifies th 0 52h DOUBLI int 14h DTPRN is located or ETALK TOOLS Address seg 103h contains the string DTPRN Copyright C 1990 RC Systems Inc if DTPRN was installed successfully The installed port na
42. esizers enabling them to support virtually all of the common voice technologies in use today The text to speech TTS synthesizer is capable of producing unlimited medium quality speech from plain English or Spanish ASCII text The linear predictive coding LPC synthesizer is compatible with Texas Instruments TSP5220 voice chip and most LPC data recorded for other LPC synthesizers It features extremely low data rates for digitized speech only 200 bytes per second 40 1 compression The PCM ADPCM and CVSD synthesizers enable DoubleTalk to play back digitized speech and sounds with very high sound quality DoubleTalk also includes programmable tone generators TGN which can be used to produce audible prompts music signaling tones or even dial a telephone from your programs DoubleTalk is software compatible with RC Systems V8600 and V8601 OEM voice boards which share DoubleTalk s software command set Programs written for one synthesizer will work with the other except for LPC and CVSD based speech which the V860X synthesizers do not support Unlike most synthesizers on the market DoubleTalk does not require any of the host computer s resources to operate e g memory IRQ s or CPU time A built in 10 MHz 16 bit processor 512K ROM and 8K RAM comprise a complete self contained text to speech conversion system An application program need only write the ASCII text to be spoken to
43. exception and the first Character exception No exceptions prior to this marker will be used when DoubleTalk is in Character mode For example Text mode exceptions optional if Character mode exceptions are not to be used in Text mode Character mode exceptions marker Character mode exceptions optional used if ROM rules are not to be used in no match situations Applications The following examples were chosen to give you some ideas of how the exception dictionary can be used Correcting mispronounced words The most obvious of all applications mispronounced words can be corrected by writing exceptions for them gt wy Q T ll n Gl ER CH EY RC SYST Gl MS 13d DOUBLETALK TOOLS The first exception corrects the pronunciation of all words containing search search searched research etc As this exception exemplifies it is only necessary to define the problem word in its root form and only the part of the word that is mispronounced ear in this case The second exception corrects the word ok but because of the left and right contexts will not cause other words joke look etc to be incorrectly translated No cussing please The speaking of specific characters or words can be suppressed by writing null exceptions for them that is exceptions in which no pronunciation is given 222 YOU fill in the blanks When 0 i
44. ext spelled out instead of spoken as words By following each letter with a phrase delimiter carriage return or null character the text will be spelled letter by letter A potential problem with this method however is with the letter A unless it is followed by another vowel it will be pronounced Gl MS 40 DOUBLETALK TOOLS as ah instead of ay This is due to the internal Text mode pronunciation rules To avoid this problem use the spelling AY Of course Character mode will avoid this problem altogether and is more responsive than Text mode Supporting User Dictionaries If you want to support user defined exception dictionaries in your program consider using the following strategy During your program s initialization phase look in the current disk directory for a specific documented dictionary file name such as USER EXH If it exists load it into the synthesizer but only after DoubleTalk has been initialized All RC Systems drivers initialize DoubleTalk when they start up including wiping out any exception dictionary this includes DTPRN INT4DAPI DTC s Dt_Init and DTOB s DTINIT functions This enables your customers to use their dictionaries conveniently in the context of your program If you are going to use your own dictionary as well load it first before loading the user dictionary Be sure to use the chained file type so the use
45. frames x 4 bytes frame of data The GROOVY TGN file supplied on this disk uses this format and can be examined using DEBUG ASSEMBLY LANGUAGE API The INT4DAPI COM program provides a set of DoubleTalk function calls similar to DOS int 21h service Calls It also emulates the BIOS int 4Dh driver built into the IBM Speech Adapter This implementation is actually a subset superset of the Speech Adapter s since DoubleTalk does not support CVSD recording only playback It does however support the foreground and background LPC playback and CVSD playback 32 kbps functions as well as some new functions including PCM ADPCM playback The driver was originally written so that programs utilizing these voice technologies could work with DoubleTalk but you may also find it useful for your own programming INT4DAPI can be run in high memory using the DOS LOADHIGH command The methods for detecting the presence of INT4DAPI detecting installation errors and removing the driver from memory are similar to that of the DTPRN driver described elsewhere The following is a summary of the return codes returned by INT4DAPI 0 INT4DAPI was successfully installed no errors 1 INT4DAPI is already resident 2 Reserved 3 Too many or invalid parameter s INT4DAPI still loads 4 Incompatible version of DOS must be 2 0 or later 5 DoubleTalk could not be located Function Calls This section describes the functio
46. interrogation routine MASM DT_LPC ASM Example assembly language LPC driver MASM DT_PCM ASM Example assembly language PCM driver MASM DT_TTS ASM Example assembly language TTS driver MASM DT_XLT ASM Assembly language phoneme translator MASM WORDS2 LPC LPC data file used in DTQB_EX BAS and DTC_EX C PORTAL PCM ADPCM data file used in DTQB_EX BAS and DTC_EX C GROOVY TGN TGN data file used in DTQB_EX BAS and DTC_EX C SPANISH EXC Source for SPANISH EXS included on Utilities disk PRINTER EMULATOR If you will only be using DoubleTalk s text to speech capabilities and possibly the DTMF generator in your applicatio emulator driver DTPRN COM is the easiest way to go small TSR program that enables emulate any one of the computer communication ports COM1 4 T applications and programming la DoubleTalk by simply printing port DTPRN requires less than 1K of memory upper memory on machines suppor LOADHIGH command s printer ports LPT Installing DTPRN n the printer DTPRN is a DoubleTalk s TTS synthesizer to or his enables most DOS and Windows 3 1 nguages to communicate with the text to be spoken to a printer and can be loaded into ting this feature using the DOS DTPRN is invoked from the DOS command line by typing the command DTPRN lt port gt N Cx R where lt port gt is one of the seven system ports listed above example DTPRN can be installe
47. king example of how to send LPC data to the LPC synthesizer TTS port The TTS port handles all 1 0 between an application program and the TTS PCM and CVSD synthesizers and tone generators Regardless of the operating mode being used data is written to the TTS port in RC SYST E ES uN 14 DOUBLETALK TOOLS RC SYST exactly the same manner be it text PCM audio samples tone generator values etc DoubleTalk knows how to interpret the data based on a mode command you give it before sending the data the default mode is always TTS TTS commands that control TTS voice attributes such as speed and pitch are also written in the same way allowing them to be embedded in text for dynamic control of the voice output Reading the TTS port returns several status flags which indicate when DoubleTalk is able to accept another data byte indicate when it is talking as well as the status of the TTS input buffer The bit definitions are described below Bit 7 6 3 4 3 2 1 0 A A A A A A A 2 0 3 SYNC SYNC2 RDY 9 AF AE 0 3 0 3 A A A A A A A A U Figure 4 TTS Port Status Flags Bit 7 Reserved Bit 6 SYNC Sync When set to 1 this bit indicates that DoubleTalk is producing output other than in LPC mode which has its own talk status bit SYNC drops to 0 immediately after output has ceased Bit 5 SYNC2 Early Sync Same function as SYNC except drops to 0 up to 0 4 sec
48. llowing the exception block halt the downloading process and nable th xceptions that were just loaded This format makes it possible for a program to load exception files by simply sending the file to the synthesizer all the details of invoking the Load mode and enabling the exceptions are taken care of automatically For example the DOS command TYPE SPANISH EXA gt LPT3 will download and activate the Spanish exceptions note that the DTPRN driver must have been installed as LPT3 for this example to work he optional characters in the brackets enable he HiAscEn bit and are included only if the ompiler detected extended ASCII characters in the ource file See Protocol Options Command for more nformation HMA tH Chained object file Same as the Standard file type but without the EOF character at the end This format is used only when the file is to be followed by another block of exceptions such as a user defined dictionary It is the responsibility of the application program to ensure that the EOF character is sent to the synthesizer after the last block of exceptions has been loaded iles normally carry the EXC extension If you omit r the source or object file name the compiler will extension s EXC and or EXS for you T MPILE commands are equivalent names exc oddnames EXS names oddnames names ODDNAMES EXS lt Enter gt
49. me LPT1 COM3 etc can be determined by examining the first four bytes at address seg 12Ch During initialization DTPRN stores the I O address of DoubleTalk s TTS synthesizer normally 29Fh for DoubleTalk PC or the base address of the COM port DoubleTalk LT is connected to in the BIOS data area This can be useful if your program needs to read or write to DoubleTalk directly such as to determine if DoubleTalk is currently speaking see the SYNC and SYNC2 flag descriptions in the Hardware 1 0 section below Exactly where the I O address is stored in the BIOS data area depends on which port DTPRN is emulating as the following table illustrates Port DTPRN Mem address installed as abs hex COM1 400 COM2 402 COM3 404 COM4 406 LPT1 408 LPT2 40A LPT3 40C For example if DTPRN was installed as LPT1 location 40 8h will contain DoubleTalk s TTS I O address 29Fh for DoubleTalk PC if the jumper block hasn t been moved from the factory setting or 3F8h for an LT connected to COM1 In the case of the internal PC card an IN instruction or its high level language equivalent to this address will return the TTS synthesizer s status flags Likewise text and commands can be output to either synthesizer with an OUT instruction or its equivalent Sending Text and Commands Any combination of text and commands can be sent to DoubleTalk via DTPRN Remember that DoubleTalk will not actually begin speaking
50. nformation 3 Function 05h TTS 3 A U AL 00h TTS status AH TTS status flags AL 01h Speak DS SI segment offset of TTS data buffer CX length in bytes AH TTS status flags AL 02h Silence output AH TTS status flags All TTS functions return the TTS synthesizer s status flags in register AH see I O Ports TTS Port below for a complete description of these flags Any combination of text and commands may be included in the TTS data buffer for subfunction 1 The tone generators can also be used with this function by simply embedding the appropriate command in the buffer RC SYST E ES uN i DOUBLETALK TOOLS HARDWARE I O There may be instances when you prefer to communicate directly with DoubleTalk or there s just no other way to get the job done such as using DoubleTalk s indexing feature This section gives you the necessary information to enable you to write your own DoubleTalk compatible drivers DoubleTalk PC All DoubleTalk PC functions are carried out by merely reading and writing to two I O ports located on the DoubleTalk card In fact DoubleTalk PC is virtually transparent to the host system in that it requires no memory based text to speech software unlike most other internal synthesizers requires no CPU overhead IROs nor DMA I O ports From a programmer s point of view DoubleTalk PC is simply two adjacent eight bit 1 0 ports residi
51. ng in the system memory map One port called the LPC port is used for operating the LPC synthesizer and reading index markers The second port called the TTS port is used for all other functions text to speech tone generation PCM output etas The six position jumper block on the DoubleTalk card determines where the two I O ports are mapped into the system The jumper sets the base address which is always the LPC port address The TTS port address is always one higher base 1 than the LPC port The section Detecting DoubleTalk shows how to determine what these addresses are CAUTION Whenever DoubleTalk PC updates the data at either port there is an inherent settling time for the bits to stabilize Although this is on the order of only a few nanoseconds it becomes significant with today s faster machines If you are monitoring a port for a change in value and also need the value such as a new index marker coming in on the LPC port you should read the port a second time after the change was detected in order to ensure reading a valid value LPC port The LPC port is normally used only with the LPC synthesizer except when reading index markers from the TTS synthesizer s Indexing below It accepts standard LPC 10 speech data in both 5220 and D6 data formats Before sending any LPC data a Speak command byte must be issued to the LPC synthesizer The Speak command determines which LPC format
52. nic energy which tends to sound more interesting than pure sinusoids in music applications DoubleTalk s sinusoidal tone generator enables the simultaneous generation of two sinusoidal waveforms Applications for this generator range from generating simple tones to telephone call progress tones such as a dial tone or busy signal The frequency range is 0 to 2746 Hz with a resolution of 4 to 11 Hz The sinusoidal tone generator is activated with the command AnJ where n is an ASCII number between 0 and 99 Note the similarity to the musical tone generator command AJ which uses no parameter The parameter n programs the internal sampling rate much like the buffered PCM mode command does in fact the sampling rate fs has the same relationship to n as the PCM mode command fs 617 155 n Immediately following the command are three binary not ASCII parameter bytes AnJ Kd K1 K2 where Kd determines the tone duration and K1 and K2 set the output frequencies of generators 1 and 2 respectively The tone duration and frequencies are not only functions of these parameters but of n as well The output amplitude is a function of the TTS synthesizer s Volume command AnV The command and parameter values are buffered within DoubleTalk and can be intermixed with text for the TTS synthesizer without restriction RC SYST ASS DOUBLETALK TOOLS E ES uN The tone duration Td
53. ns supported by INT4DAPI Those functions which are extensions or additions to the original IBM Speech Adapter BIOS functions are denoted by an asterisk All INT4DAPI functions are invoked by loading the AH register with the desired function number AL with the subfunction number if applicable and calling software interrupt 4Dh int 4Dh On return the AL register will contain one of the following codes 0 No errors encountered ik Undefined command 2 Speech in progress U 3 Function 00h Reset gt A U The Reset function initializes the LPC functions for 5220 data and normal playback speed no other function is performed RC SYST E ES uN 10 DOUBLETALK TOOLS a 3 Function Olh CVSD 3 AL Olh Playback using speed table DS SI segment offset of CVSD data buffer CX length in bytes BL speed table ignored AL 03h Playback using user defined speed DS SI segment offset of CVSD data buffer CX length in bytes BX user speed divisor ignored U 3 Function 02h LPC Background 3 U AL 00h LPC status AL 02h LPC playback DS SI segment offset of LPC data buffer CX length in bytes AL 03h LPC format speed BL format code 5220 data normal default 5220 data fast D6 data normal D6 data fast WNnN RO ll The LPC Background mode is simulated by utilizing the LPC data buffer within DoubleTalk no interrupt processing takes
54. ond earlier when using the TTS synthesizer only This enables a program to send another phrase to the TTS synthesizer just before the current one has completed improving the response tim Bit 4 RDY Ready When set to 1 indicates the TTS port is ready to accept a byte of data Bit 3 AF Almost Full When set to 1 indicates that less than 300 bytes are available in the TTS input buffer AF is always 0 in the PCM TGN and CVSD modes Bit 2 AE Almost Empty When set to 1 indicates that less than 300 bytes are remaining in DoubleTalk s input TTS or PCM buffer AE is always 1 in the TGN and CVSD modes Bits Reserved 1 0 Note that the SYNC flag can be used to effectively disable the internal text tone PCM data buffers by waiting for it to drop to 0 before sending any more data to the synthesizer S the DT_TTS ASM file for a working example of how to send data through the TTS port To avoid losing data your program should test the RDY flag before each byte is output The DT_Tts routine included in the DT_TTS ASM E ES uN Ls DOUBLETALK TOOLS file shows the recommended method of doing this The only exception to this rule is when stopping the TTS synthesizer with the X character in this case the RDY flag should be ignored in order to yield the fastest response time possible as well as avoid potentially long delays should the input buffer become full DoubleTalk L
55. oubleTalk drivers and libraries supplied on this disk all incorpora present LT was detected te a common routine for determining if DoubleTalk is and where it is located The source code for this routine can be found in the determines what the PC was detected or DT_TTS ASM file DT_Init This routine LPC and TTS I O port addresses are if DoubleTalk the base address of the COM port if DoubleTalk The routine also initializes DoubleTalk to the factory default settings CAUTION RC SYST Gl The method used to detect DoubleTalk PC assumes that the TTS and LPC ports will have certain specific values when they are read forming a Signature that is unique to DoubleTalk PC If DoubleTalk happens to be talking at the time DT_Init looks for it it will not be able to locate DoubleTalk since one or both of the ports will have status bits that are in the wrong state For similar reasons DoubleTalk LT must also be idle in order for it to be detected 18 DOUBLETALK TOOLS Indexing I t D he pro E w m i E ndex markers ar gress of speech This way n issuing the command A 1I for each 99 W m hen Do arker n the ubleTalk has spo number back to t binary number between command to place it will automatically wrap arou ken the text he program O and 99 the marker ach word relative parameter capability he
56. p to 64K bytes in length bytes 0 1 file header bytes 2 3 length of first entry first entry s data length of entry n entry n s data The LPC files supplied on the Utilities and Developer s Tools disks use this format and can be examined using DEBUG PCM File Format The PCM data file format is similar to the LPC file format The number of entries variable is eight bits in length instead of 14 This limits the number of sounds that can be contained within a PCM data file to 255 but considering the inherent size of PCM sounds this is actually quite a large number The length variable for each e e ntry is three bytes instead of two allowing individual sound ntries to be up to 16MB in length RC SYST Gl MS msgid ic DOUBLETALK TOOLS Bit 7 6 5 4 3 2 1 0 A A A A A A A 3 NUMBER O E ENTRIES 3 byte 0 A A A A A A A A U 15 14 13 12 11 10 9 8 U A A A A A A A E 3 FMT SAMPLING RATE 3 byte 1 A A A A A A A A U Figure 2 PCM Data File Header The second byte of a PCM data file contains two types of information about the fil the rate at which the data was originally sampled and the PCM data typ The low order seven bits contain a number between 0 and 99 decimal corresponding to the sampling rate variable in the PCM Mode command see PCM Mode section below Note that the value stored here does not affect the actu
57. place however as with the Speech Adapter The 4096 byte limit of the data buffer in the Speech Adapter does not apply to INT4DAPI Subfunction 3 sets the data format and playback speed for all subsequent subfunction 2 calls U 3 Function 03h LPC Foreground 3 AL 00h LPC status AL 02h LPC playback DSSI segment offset of LPC data buffer CX length in bytes AL 03h LPC format speed BL format code 5220 data normal default 5220 data fast D6 data normal D6 data fast WNRo ll sk DOUBLETALK TOOLS RC SYST E ES uN The LPC Foreground mode is simulated by disabling the LPC data buffer within DoubleTalk The 4096 byte limit of the data buffer in the Speech Adapter does not apply to INT4DAPI Subfunction 3 sets the data format and playback speed for all subsequent subfunction 2 Calls 3 Function 04h PCM 3 A U AL A 00h PCM playbac DS ST segment offset of PCM data buffer CX length in bytes BL sampling rate AL 01h ADPCM playback DS SI segment offset of ADPCM data buffer CX length in bytes BL sampling rate This function provides support for both PCM and ADPCM speech Note that the sampling rate parameter passed in register BL may take on any value between 0 and 99d corresponding to the 100 sampling rates supported by DoubleTalk e g BL 78d programs a playback rate of 8 kHz See the section PCM Mode below for more i
58. r dictionary will load properly Refer to the section Exception Compiler above for more information about the dictionary file formats To summarize these are the steps your program should follow 1 Load and initialize any drivers your program may use for interfacing with DoubleTalk 2 Load and output the application program s exception dictionary if used It should be of the EXH chained file format 3 Load and output the user dictionary if it exists It should also be of the EXH file format 4 Output the EOF character 1Ch to the synthesizer to signal the last of the exceptions have been loaded Of course if only one dictionary is to be used either th application s or user defined but not both the EXA or EXS file formats may be used to simplify the loading process RC SYST Gl MS S DOUBLETALK TOOLS APPENDIX A LPC Speech Encoding Services The following companies are known to offer LPC speech development services Their appearance here is not an endorsement by RC Systems Creative Education Institute David Rousch P O Box 7306 Waco TX 76714 817 751 1188 Laureate Learning Systems Burnie Fox 110 E Spring St Winooski VT 05404 802 655 4755 Texas Instruments Regional Technology Center 17891 Cartwright Dr Irvine CA 92714 714 660 8292 42 DOUBLETALK TOOLS RC SYST E ES uN APPENDIX B Additional
59. r short passages is to simply string together commas and or periods where each pause is to take place Commas create a medium pause periods create a long pause Commas and periods may be combined to create even longer pauses If you don t want the downward inflection associated with a period to occur insert at least one space between it and the word preceding it Now le Now le me think inflects downward me think no inflection CF LA The second method of creating pauses in the speech makes use of the synthesizer s exception dictionary Say for example that you wanted a long pause to be generated between indented paragraphs of text in a text reader program It is not practical to insert additional punctuation marks in the text the program will be reading since the text content is generally not known beforehand But let s say we loaded the following exception into the dictionary J 3 spaces This exception causes the speech to pause actually two long pauses comprised of the two phonemes whenever thr or more consecutive spaces appear in the text namely the indent of each paragraph Note also that this method will not affect the inflection in any way as did the first method An additional benefit is that this method will work for virtually any text input Forcing Character Pronunciation RC SYST It is not necessary to change from Text mode to Character mode to have t
60. s in a second group an overall cleaner appearanc o on he always ng would be character n one This gives and can prove to be helpful if the need arises to troubleshoot any problems in your dictionary Text not matched by the xceptions xample f the dictionary defi nput In any case if haracter the according to the built I e e E o i W i Generally ould probably be comprehensive e English pronunciat dictionary t is possible that some input text will depending on the nature of the exceptio if a dictionary was writ hose words would be defined by t ther words would be handled by t te he he nu nough to an exception is no excep excep ned the pro n to handle unus nciation fora not match I O tions tions n n no handle found be give a n u S E n t tion will in ROM English p the automatic switchover to the the dictionary is used to correc mispronou ronunciatio ROM rules ny of dict al wo all a pa is desirable his case he other hand her language the ionary For rds only no it types of rticular to that character n rules if nced word essence it is defining exceptions to the ROM rules switchover is not desi letter a will always group with the excepti ther red however be matched for ar ntext nd S since i n If the automatic
61. s not zero When we read addresses or lists of numbers we often substitute the word oh for the digit 0 For example we might say 1020 North Eastlake as one oh two oh North Eastlake The digit 0 can be redefined in this manner with the following exception 0 OW Arithmetic operators Some characters may have more than one name for example may be read as slash or divided by depending on the context Such characters can be redefined if their default names don t fit the application For example the arithmetic operators etc can be defined for mathematical applications with the following exceptions D IH V AY D IH D B AY M AH L T IHP L AY D B AY R EY Z D T UW etc Acronyms and abbreviations Acronyms and abbreviations can be defined so the words they represent will be spoken KW K IH L OW W AA T DR D AA K T ER TV T EH L AX V IH ZH IX N RC SYSTEMS 32 DOUBLETALK TOOLS Heteronyms Heteronyms are words that have similar spellings but are pronounced differently depending on red and wind can be used to fix up thes Control Suppose a lin the wind blew the context such as read and e ambiguities word close to of text required th wind the clock by including no characters in the text fragment of the exception reed and Exceptions n printing be pronounced as it is in a close call instead of as
62. sary learing the TTS synthesizer with any of the following TTS commands through the TTS port will also clear the marker from the LPC port I s T W s Cc xX Clear Reinitialize he marker in this manner also resets the relative index ensuring that relative indexing always begins at 0 Clearing t value It is also good practice before quitting your application that you issue one of these commands preferably A to force the LPC status back to its normal idle stat Otherwis the next application may not be able to find DoubleTalk since most find routines expect the LPC port status value to be 7Fh r DoubleTalk LT RC SYST DoubleTalk LT transmits index markers via its serial port Normally an interrupt handler in your program that processes incoming 19 Gl DOUBLETALK TOOLS characters from the COM port will interrupt handler is invoked only it is not necessary to clear th CAUTION The Echo emulation feat recognizes 40h as synthesizer s status T to be emitted from the transmitted to DoubleTa ensure that your progra s a spurious marker iltering any chara hecking that each rece imits 0 to 99 The L much larger number u he range of valid mark a f G d a E Not all DoubleTalks support indexin Early DoubleTalks PCs did not s To prevent your application from markers that may never come it s DoubleTalk card it is using s
63. st seem all uage textbook the language libraries have tion guides ules into i scribe the pronunciation r h exception file SPANISH The following exceptions d e Spanish English words an also be reversed 33 EXC was written Exception dictionaries even allow DoubleTalk to read foreign emonstrate how DOUBLI ETALK TOOLS Tips Ma do more harm than good Exceptions intended to fix words such as word endings otherwise correctly pronounced words Ta exception s position relative to others is just as content of the exception itself Exception anomalies On rare occasions an excep ke care in how your exceptions are organized Remember tion may not work as expected ke sure that your exceptions aren t so broad in nature that they broad classes of are particularly notorious for ruining an important as the This occurs when the ROM based pronunciation rules get control before the exception does The followi happen Suppose an exception redefi the long oh Canada Since the word is o exception redefines only the o PR O CESS 0 But much to our horror DoubleTalk simply refuses t Canadian accent It so happens DoubleTalk has a rule in its ROM whic like this S PRO P R AA This rule translates a group of three characters i one as most of the ROM rules do Because the text translated as a group the o is processed along wit pr
64. straightforward 1 Program the desired volume level with the Volume AnV command A volume setting of 5 will cause the PCM data to be played back at its original volume level This step is optional 2 Issue the Buffered PCM Mode command An The value of n will set the sampling rate within DoubleTalk 3 Immediately begin transferring the PCM data to DoubleTalk The same methods employed for sending ASCII data to the text to speech synthesizer should be used see Hardware I O section above PCM data must be sent to DoubleTalk as linear eight bit signed data 127 to 127 0 midscale Note that if the AE status flag is 1 a block of 4096 300 3796 bytes may be transferred to DoubleTalk without concern of overflowing the DAC buffer This can be beneficial in applications that need to do background tasks concurrently with PCM based sounds 4 After the last byte of PCM data has been sent to DoubleTalk send the value 80h 128d This signals DoubleTalk to terminate PCM mode and return to the text to speech mode of operation Note that up to 4096 bytes of PCM data may still remain in the DAC buffer so DoubleTalk may continue producing sound for as long as 1 second 4 kHz sampling rate after the last byte of data has been sent DoubleTalk s SYNC flag will not be cleared until all of the speech data has been output to the DAC at which time DoubleTalk will again accept data for the text to speech synthesizer
65. t is masked Default Disabled 0 Sync2En Early Sync Enable Enables Sync2 timing when set to 1 If enabled software and hardware sync endings occur approximately 0 4 second early If disabled sync endings coincide with actual ending of speech production This control bit SYNC2 flags definitions DsrEn DSR If enabled corresponds to choosing between the SYNC and found in DoubleTalk PC see TTS port flag above Default Disabled 0 Enable Enables DSR handshaking when set to 1 DoubleTalk will not transmit data to the host if the DSR serial status line is false except for index markers where DSR is ignored Default Disabled 0 HSyncEn Hardware Sync Enable Enables hardware synchronization If enabled DoubleTalk carries sync status on the RI Ring Indicator serial status line End timing is affected by Sync2En Default Enabled 1 SSyncEn Software Sync Enable Enables software synchronization If enabled DoubleTalk transmits ASCII B when speech affected by Detecting DoubleTalk Because i system has if any the first DoubleTal begins and E when speech ends End timing is Sync2En Default Disabled 0 t is generally unknown which DoubleTalk any particular and which port addresses or COM port are used thing a DoubleTalk driver must do is determine if k is present and where The D
66. t transcription Rule precedence Since DoubleTalk uses its translation rules in a sequential manner the position of each exception relative to any others must be carefully considered For example consider the following pair of exceptions 0 OW O UW RC SYST Gl MS ZO DOUBLETALK TOOLS he first excep ronounced OW ny contex tion states that o followed by e the o sound in boat Th i cond S f the exceptio eached sinc ns wer h 0 reversed the 0 n general tightly d fined exceptions ontext restric those with li tions tle or T P P a i r I c RAT R A RATING R R J m ea H This is an example of exception RATING wil match first According to these exceptions pronounced rat ing or y lace any restriction on what must come before or after o t will match and receive the UW pronunciation is to be xception does not so o in Note that xception would never be xception will always match o in any context should preced no context definiti H NG l never be used bec ons how not to organize exceptions aus RAT those containing many loosely defined xceptions de will the word rati It can be beneficial to also group exceptions by the firs of the text fragments group that is r and s all of the A exceptions i all the B exception
67. to be converted If the extension is omitted from the file name wav is assumed by default The optional C switch is used to invoke the ADPCM compression algorithms otherwise the output file will be linear PCM Sn is an optional silence encoding threshold parameter used in conjunction with the C switch where n can be any value between 0 and 9 default 2 By default the output from the utility is a file which has the same name as the input file but with the extension pcm Silence threshold The silence threshold parameter Sn sets the maximum level that is to be considered silence by the ADPCM encoding algorithms The larger n is made the higher the compression ratio will be However excessively high values of n can cause the decoded ADPCM output to become somewhat grainy sounding The point at which this becomes objectionable depends on many factors such as desired output quality vs storage requirements recording level background noise sound source etc Experimentation with this parameter is the best way to find the optimum setting Note that you may use a different Silence threshold value for different sound files the decoding algorithm can dynamically adapt to changing thresholds A silence threshold of 2 will be used if the threshold is not specified Creating library files Multiple PCM sound files can be concatenated together for use with the Basic and C libraries with the DOS
68. uppo determine this is to send it an i null character If nothing comes change in value from 7Fh the ca Earlier version DoubleTalk PCs ca with a simple user installable RO Interrogating DoubleTalk The A command built into both D read the current settings of Doub from the Interrogate command are Serial number word 0 7Fh 0 7 ROM version variable length Mode byte C D T 0 Punc level byte nB 0 7 Formant freq byte nF 0 9 Pitch byte nP 0 99 Speed byte nS 0 9 Volume byte nv 0 9 Tone byte nX 0 2 Expression byte nE 0 9 Exc dict loaded byte L l exce otherwise Exc dict status byte U l exce otherwise Free RAM byte L page buffer functi installed 8K 3 Articulation byte nA 0 9 RC SYSTEMS 2 handle the markers Since the when a new index marker comes in e marker as with DoubleTalk PC ure of DoubleTalk LT a request for the LPC his causes a one byte value serial port whenever is lk LT Take precautions to m does not interpret this this can be done either by cters from the text or by ived marker is within PC status byte is generally sually 251 far outside ers g upport indexing all LT models do hanging up by waiting for index hould first determine if the rts indexing The easiest way to ndex marker followed by a return or back i e the LPC port doesn t rd doesn t support indexing n be updated to support indexing M upgrade oubl

DOUBLETALK DEVELOPER`S TOOLS

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