System Requirements
Contents
1. LUFS Integrated Loudness LUFS Loudness Range LU Variance LU True Peak L dBTP 99 99 99 99 1 2 00 00 00 10 0 0 3 00 00 00 20 99 99 99 0 0 99 4 00 00 00 30 99 99 99 0 0 99 F 00 00 00 40 99 99 99 0 0 99 6 00 00 00 50 99 99 99 0 1 2 69 3 E 00 00 00 60 86 6 95 4 99 0 1 8 70 1 8 00 00 00 70 34 6 43 3 34 6 0 21 65 8 9 00 00 00 80 32 2 41 33 2 0 25 66 6 10 00 00 00 90 32 40 7 32 8 0 2 8 67 5 11 00 00 01 00 31 9 40 6 32 5 0 3 68 4 12 00 00 01 10 34 9 40 5 32 9 0 3 1 69 2 13 00 00 01 20 32 3 38 32 8 0 3 2 70 1 14 00 00 01 30 30 2 36 7 32 3 0 3 4 70 9 15 00 00 01 40 30 36 6 32 0 3 5 71 8 16 00 00 01 50 30 36 6 31 7 0 3 6 72 7 17 00 00 01 60 33 36 5 31 8 0 3 6 73 5 18 00 00 01 70 29 34 2 31 5 0 37 9 9 19 00 00 01 80 23 4 30 8 29 9 0 3 9 10 8 20 00 00 01 90 23 1 30 6 28 8 0 4 11 6 21 00 00 02 00 23 30 5 28 0 4 1 12 6 22 00 00 02 10 24 1 30 4 27 6 0 4 2 13 4 23 00 00 02 20 28 4 29 9 27 6 0 4 2 11 5 24 00 00 02 30 23 2 28 2 27 2 0 43 10 7 25 00 00 02 40 22 9 28 26 8 0 44 11 5 26 00 00 02 50 22 7 27 9 26 5 0 44 12 4 27 00 00 02 60 23 4 27 9 26 3 0 45 13 2 28 00 00 02 70 28 27 6 26 3 0 45 11 7 29 00 00 02 80 23 1 26 5 26 1 0 45 11 3 30 00 00 02 90 23 26 4 25 9 0 4 5 12 1 31 00 00 03 00 22 9 26 4 25 7 0 4 5 13 32 00 00 03 10 23 5 26 3 25 6 0 46 13 9 33 00 00 03 20 29 6 26 3 25 7 0 46 12 4 34 00 00 02. 3 30 23 3 25 4 25 6 0 46 1 77 35 00 00 03 40 23 1 25 3 25 5 0 46 12 5 ISOOO sneat 7 CZ nas f a 11 Sheet 1 1 Default STD Sum 0 SD 100 Figure 4 Exported Loudness Data LCAST Surround exports the following columns e Time HH MM SS 000 e Momentary loudness LUFS e Short term loudness LUFS e Integrated loudness LUFS e Loudness range LU e Variance LU e True peak levels for all channels dBTP Channel Layouts In DAWs that support channel layout information LCAST Stereo reports to the DAW that it supports the following channel layouts e Mono e Stereo LR LCAST Surround also supports the following channel layouts e MPEG 3 0 LR e Quadraphonic L R Ls Rs e MPEG 5 0 LR CLs Rs e MPEG 5 1 LR C LFE Ls Rs In DAWs that do not support channel layout information LCAST will map the input channels as follows e Channel 1 L e Channel 2 R e Channel 3 C e Channel 4 LFE e Channel 5 Ls e Channel 6 Rs When you insert LCAST into a new project verify that the channels are mapped correctly or you may obtain incorrect loudness readings 15 Resources MeterPlugs http www meterplugs com ATSC A 85 http www atsc org cms standards a_85 201 la pdf EBU R128 http tech ebu ch webdav site tech shared r r128 pdf EBU TECHNICAL Loudness http tech ebu ch loudness ITU BS 1770 2 http www itu int dms_pubrec itu r rec bs R REC BS 1770 2 201 103 I PDF E pdf 16 Gloss
3. LCAST User Manual AN MeterPlugs Contents Welcome to LCAST Loudness Meter System Requirements Compatibility Installation and Authorization Loudness Metering True Peak Metering LCAST User Interface Your First Loudness Measurement Presets and Loudness Standards Exporting Loudness Data Channel Layouts Resources Glossary Welcome to LCAST Loudness Meter MeterPlugs LCAST Loudness Meter is an advanced metering system designed for the content creator the broadcaster and ultimately the audience Digital transmission of content allows for multi channel audio and increased dynamic range but must be managed properly to ensure a consistent enjoyable listening experience LCAST provides you with a comprehensive set of tools for measuring analyzing and understanding the loudness characteristics of programmes Its minimalist elegant interface is approachable and helps to simplify the process of measuring loudness This guide will introduce you to the concepts behind loudness and true peak metering and then take you on a tour of LCAST Loudness Meter We at MeterPlugs would like to thank you for choosing LCAST and welcome you to the future of metering System Requirements e Mac OS X v10 5 7 or greater e Windows XP Vista 7 or 8 e AAX Audio Unit or VST 2 4 compatible DAW Compatibility Mac LCAST comes in three versions on the Mac an AAX plug in for Pro Tools 10 3 7 an Audio Unit and a VST 2 4 plug in All plug ins a
4. any loudness requirements specify a target value for integrated loudness The unit of loudness is LUFS when the alignment level is 0 see the Options panel below and LU otherwise 2 Loudness Range Loudness range gives an indication of the variation present in the integrated loudness measurement and is useful for determining whether dynamic compression is needed The 7 unit of loudness range is LU 3 Maximum Momentary Loudness Maximum momentary loudness measures the greatest level that the momentary loudness measurement reaches This value is useful for limiting loudness peaks in short programmes less than 30 s 4 Maximum True Peak The maximum true peak display shows the highest peak level reached on all channels The display turns red when the clip threshold is exceeded see the Options panel below The unit for true peak levels is dB TP which stands for decibels true peak 5 History Plot The history plot depicts the integrated short term and momentary loudness levels over time Each series can be shown or hidden see the Options panel below Click and drag the plot to pan up or down Shift click and drag the plot to zoom in or out Press the home button to restore the default plot bounds which can be adjusted in the Options panel 6 True Peak Meters Each meter displays a channel s true peak and maximum true peak level When the true peak level exceeds the true peak clip level as set in the Options panel the c
5. ary ATSC Abbreviation for Advanced Television Systems Committee DA Abbreviation for digital to analog Digital to analog conversion is the process of constructing a continuous analog signal from a discrete digital signal DAW Abbreviation for digital audio workstation A digital audio workstation is a piece of software that acts as a virtual studio often allowing you to record edit and mix audio tracks dBTP Abbreviation for decibels true peak EBU Abbreviation for European Broadcast Union www ebu ch LKFS Abbreviation for loudness k weighted referenced to full scale LU Abbreviation for loudness unit LUFS Abbreviation for loudness unit referenced to full scale ITU Abbreviation for International Telecommunication Union www itu int RMS Abbreviation for root mean square Calculating the root mean square of a signal s samples can give an indication of the power in the signal 17
6. ause button is toggled off To determine the integrated loudness of an entire programme perform the following steps Insert LCAST on your DAW s output bus and open the LCAST UI e Toggle LCAST s play button to start the integrated loudness measurement e Press your DAW s play button to start the programme e When the programme is finished toggle LCAST s play button to stop the measurement e Take note of the integrated loudness loudness range maximum momentary loudness and maximum true peak levels If they do not meet your requirements make the necessary gain compression and limiting adjustments and repeat the previous steps until you obtain the desired levels Pre and Post Silence Ideally LCAST s loudness measurement would start immediately when your DAW starts playing the programme and stop when your DAW stops Be aware that some DAWs send a silent signal through plug ins even when no audio is playing For gated measurements this is usually not a problem since any pre and post silence is ignored however short un gated measurements may be biased slightly by this silence For example if 2 s of silence are fed into LCAST before a short 5 s clip the loudness reading may be compromised It is important to be aware of this when taking un gated measurements 11 Presets and Loudness Standards LCAST includes presets for the major loudness standards and can be configured to support others A loudness standard sp
7. between 40 LUFS and 10 LUFS for example Loudness range quantifies the loudness variation in a programme and is expressed in LUs Gating Long quiet passages in a programme will lower loudness readings For example in a movie dialogue between two characters may contain pauses If these pauses last a prolonged period of time they will lower the loudness measurement To account for this gating is used to ignore passages that have loudnesses under a given threshold LCAST supports both gated and un gated measurements True Peak Metering Many peak meters fail to accurately detect peaks in audio signals because they don t detect inter sample peaks peaks occurring between samples Inter sample peaks may be created when a DA converter interpolates between digital samples in order to create a continuous analog signal Inter sample peaks are quite common so it is important to detect them LCAST uses true peak metering to improve the accuracy of peak detection by quadrupling the number of samples in an input signal before detecting peaks LCAST User Interface This section describes the LCAST user interface UI components which are identified by numbered circles 1 through 7 in Figures 2 and 3 LOUDNESS TRUE PEAK o 2 _ LRA MAX 5 5 MAX L R C LFE Ls Rs EN MeterPlugs Figure 2 LCAST User Interface 1 Integrated Loudness Integrated programme loudness quantifies the overall loudness of the entire programme M
8. ecifies a set of loudness and true peak requirements target levels for integrated loudness and maximum levels for momentary short term and true peak measurements This helps to create consistency between programmes which should lead to a more enjoyable listening experience What follows is a brief overview of the most popular loudness recommendations ITU BS 1770 3 This document created by the International Telecommunications Union ITU contains algorithms for measuring perceived loudness and true peak levels of multi channel signals The loudness algorithm computes a single loudness value for an entire programme which is expressed in LKFS Two loudness gates are used to filter out quiet passages so that they do not bias the measurement The first gate is an absolute gate with a threshold of 70 LKFS while the second gate is a relative gate with a threshold of 10 LKFS EBU R128 This document created by the European Broadcast Union EBU covers loudness metering specifications and recommended loudness practices for broadcasters EBU R128 defines three loudness measurements integrated short term and momentary Integrated loudness is computed using the loudness algorithm listed in ITU BS 1770 2 while short term and momentary loudness are computed using 3 s and 400 ms windows respectively The unit of loudness is LUFS which is equivalent to LKFS When loudness values are given relative to a non zero target loudness the relative unit of l
9. f a burst of loudness the overall loudness of a passage and the mixture of frequencies We desire a meter that mimics the way a human perceives loudness a so called perceived or subjective loudness meter Such a meter improves upon peak root mean square RMS and voltage unit VU meters by more accurately modeling human hearing This allows broadcasters to provide more uniform loudness levels across programmes leading to a more enjoyable listening experience For this reason loudness metering is quickly becoming standard practice in broadcast Loudness Units The basic unit of loudness is LUFS which stands for Loudness Unit referenced to full scale An equivalent unit LKFS stands for Loudness K weighted referenced to full scale When loudness values are referenced to a target level rather than full scale the relative unit of loudness is LU which stands for Loudness Unit For example if the target level is 23 LUFS then 1 LU is the same as 22 LUFS Loudness levels can apply to an entire multi channel programme or to a small portion of that programme In other words we can say things like this song s loudness is 23 LUFS or the momentary loudness over the past 400 ms is 24 LUFS Loudness Range In addition to knowing how loud a programme is we also wish to know how much its loudness varies A programme with a constant loudness of 23 LUFS may need to be treated differently than one that fluctuates
10. lip indicator light turns on Click the clip indicator light to reset the meter s maximum true peak level 7 Control Strip e Play Button Start stop all loudness and peak measurements e Pause Button Pause resume all loudness and peak measurements This is useful when you want to disregard portions of a programme e Reset Button Reset all loudness and peak measurements Home Button Restore the default history plot bounds as set in the Options panel e Options Button Open the Options panel e Save Button Save loudness and peak data to a file This is useful when you want to analyze loudness and peak data in an external application This feature is only available in LCAST Surround e00 Options True peak clip l Target level 23 _ Enable relative scale V Enable loudness gate V Use host transport Minimum level 59 Maximum level 5 Vi Show momentary loudness V Show short term loudness _ Show short term variance V Show integrated loudness Top segment am Middle segment 18 B Bottom segment 28 wi Figure 3 Options Window Options Panel True peak clip The threshold over which a peak level is considered to be clipped When this value is exceeded the maximum true peak display 4 turns red and displays the offending peak level e Target level The desired integrated loudness level LUFS This option is used in conjunction with the relative scale toggle e E
11. ming the following steps e Create a text file named Icast license txt lcast stereo license txt for LCAST Stereo containing the e mail address that you used when purchasing LCAST your serial number and the license signature each on a separate line A sample license file is shown below e Place Icast license txt lcast stereo license txt in the same directory that LCAST is installed in For example Library Audio Plug Ins Components on Mac OS X or C Program Files Steinberg VSTPlugins on Windows Once LCAST has been successfully authorized the authorization dialog will no longer be displayed when LCAST is run If you have difficulty authorizing LCAST try the following If you are authorizing LCAST using the authorization dialog Figure 1 ensure that you are connected to the Internet e If you create the license file manually make sure it is a plain text file e Contact us We re happy to assist you Sample License File your email yourdomain com LCT10 C8H2Z Y24QB Q8XNT 2H4EN MC4CFQCXPK4UfE3vWzW071UxB6F800yhpgIVAMPXs 1 Isfl3ZguJvm 3LhVWtjBSv Loudness Metering When talking about loudness an important question arises how is loudness measured The human ear is generally most sensitive to signals in the 1 kHz 5 kHz range Frequencies lower and higher than this when played at the same volume level are perceived as being quieter Many factors can affect the perception of loudness the age of the listener the duration o
12. nable relative scale When enabled loudness levels are displayed on a relative scale The target level is subtracted from the full scale loudness value and the unit of loudness is LU a relative level For example if the target level is set to 23 LUFS then 22 LUFS is equivalent to 1 LU e Enable loudness gate The loudness gate is designed to disregard quiet portions 9 of the programme so that the integrated loudness and loudness range are not greatly affected by them An absolute gate of 70 LUFS and a relative gate of 10 LU are used This parameter takes effect when a new integrated measurement is started Use host transport Bypass LCAST when the host transport is not playing This feature is not supported by all hosts Minimum Maximum level The default minimum maximum value shown in the history plot If the plot is panned press the home button to restore these values Show momentary short term integrated loudness and loudness variance Show or hide the history plot series for each of these measurements Top middle bottom segment Set the colors and levels of the history plot s background segments Click the color buttons to open a color chooser 10 Your First Loudness Measurement Momentary short term and integrated loudness levels are shown in LCAST s history plot Momentary and short term measurements are updated continuously while the integrated measurement is updated when the play button is toggled on and the p
13. oudness is LU EBU R128 recommends that programmes be normalized to 23 LUFS using the gating scheme described in ITU BS 1770 2 ATSC A 85 This document created by the Advanced Television Systems Committee ATSC covers recommended practices for loudness metering and content delivery A 85 recommends a target loudness of 24 LUFS un gated measured over the entire duration of the programme for content delivery and exchange For live events it recommends a sliding 12 window measurement that is 3 s 10 s in duration iTunes This iTunes feature allows you to hear all of our songs at a similar volume Although Sound Check Apple has not publicly stated how they perform volume normalization independent tests suggest that songs are normalized to 16 5 LUFS Presets LCAST has the following presets ATSC A 85 EBU R128 LUFS EBU R128 LU 9 EBU R128 LU 18 ITU BS 1770 3 iTunes Sound Check OP 59 13 Exporting Loudness Data In LCAST Surround you can export the data displayed in the history plot saving it to a comma separated values CSV file which can be opened in a spreadsheet application such as Microsoft Excel or OpenOffice Press the save button to export a log file eoa _ blah csv OpenOffice org Calc a Bla 8 B88 Vs KER g 682 bye HAAS O Fr met E arial Bh B B UE HA AGH EE DDA Al E Time HH MM S5 000 KE A B c D E F G ime HH MM S5 000 _ Momentary Loudness LUFS Short Term Loudness
14. re 32 64 bit universal binaries Windows LCAST is available as a 32 64 bit AAX plug in for Pro Tools 10 3 7 and a VST 2 4 plug in on Windows Installation and Authorization Mac To install LCAST on Mac OS X run the installer and follow the on screen instructions LCAST will be installed into the following folders e AAX Library Application Support Avid Audio Plug Ins e AU Library Audio Plug Ins Components e VST Library Audio Plug Ins VST Most DAWs will scan these folders to discover plug ins See your DAW s manual for more information Windows To install LCAST on Windows run the installer and follow the on screen instructions LCAST will be installed into the following folders by default e AAX C Program Files Common Files Avid Audio Plug Ins e VST C Program Files Steinberg VSTPlugins You may need to configure your DAW to scan this directory See your DAW s manual for more information Authorization When you first install and run LCAST an authorization dialog will prompt you for your e mail address and serial number The e mail address must be the one that you used when purchasing LCAST LCAST Loudness Meter TAN MeterPlugs Email _ Serial Number Cancel Authorize Figure 1 LCAST Authorization Authorizing LCAST using the authorization dialog Figure 1 requires an Internet connection If you prefer it is possible to authorize LCAST without an Internet connection by perfor
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