BS1770GAIN

Copyright © 2014-2018 by Peter Belkner (http://home.snafu.de/pbelkner/)

This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 2 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with this program. If not, see <http://www.gnu.org/licenses/>.

BS1770GAIN is a loudness scanner compliant with ITU-R BS.1770 and its flavors EBU R128, ATSC A/85, and ReplayGain 2.0. It helps normalizing the loudness of audio and video files to the same level.

Nanos gigantum humeris insidentes: This project is dedicated to my European heritage. It is strictly to be understood as a statement against the "sweet" liberal lie of "multiculturalism" which is going to destroy Europe as we know it, in particular against the Merkel regime selling out Europe for nothing as we watch.

Home:   http://bs1770gain.sourceforge.net/
Project:   http://sourceforge.net/projects/bs1770gain/
Download:   http://sourceforge.net/projects/bs1770gain/files/bs1770gain/

Content

  1. History
  2. Introduction
  3. Usage
  4. Command Line Syntax
  5. Test Cases

1. History

'
2018-??-?? 0.5.0-β4
  • With v0.5.0-β1 we introduced guarding bs1770gain against being run with incompatible FFmpeg and SoX libraries. At least this was the goal. In case of the FFmpeg libraries the test was done against the full version consiting of major, minor, and micro version numbers. This was by far to much. As far as we know just a bump of the major version number indicates some change in binary compatibility. This release relexas the test to FFmpeg major version number.
  • BTW:
    • Around the time we where releasing v0.5.0-β1 we've received the following mail from some Debian official:
      From: daniel <daniel@xxxxxxxx.xxx>
      Date: 29.07.2018 19:36
      To: Peter Belkner <pbelkner@snafu.de>
      Subject: Re: Bug#883198: Fixed

      Hi Peter,

      Thanks for the link. I was sorry to see the statement about European heritage on this page. Im not sure how a Debian or Free Software user who isn't European is meant to react to that.

      Daniel

      -------- Original message --------
      From: Peter Belkner <pbelkner@snafu.de>
      Date: 29/07/2018 5:36 pm (GMT+00:00)
      To: 883198@bugs.debian.org
      Subject: Bug#883198: Fixed

      For details refer to http://bs1770gain.sourceforge.net/index.html#0.5.0-beta-1

      Peter
    • To be honest: we're simply not interested in "how a Debian or Free Software user who isn't European is meant to react." We develop open source software, and we're from Europe. We're interested in how we feel as European when overrun by the third world. To us the idea of developing open source software was always (and possibly will ever) be educational similar to academia and sience. Add the internet and you can bring it to the smallest village all over the world. In the ages of the internet there's really not the slidest need for someone interested in open source software leaving his home somewhere else and coming to Europe for some silly promises nobody ever can keep (for a free lunch) and that way destroying all the infrastucture we've created here in Europe in the course of thousands of years. Stay at home and learn!
    • We're convinced that the so called refugee crisis is an event staged by those literally nobody is even allowed to call by their name (except themselfs and at least here in Europe, cf. the German fairytale Rumpelstiltskin: we have to break the spell and again have to learn to call the chosen people by their name as it was usual for centuries and just nowadys is "forbidden" by some strange "laws" like § 130 volksverhetzung dictated by themselfs) in order to make their wet dream of a new world order become true, and finally make them the masters of the world: liberté, égalité, fraternité for everybody except them who are chosen to be the masters.
2018-08-05 0.5.0-β3
  • User Martin reported that the Windows build of prior versions is broken in that when called from a Windows cmd box rather than from MSYS2 it might come up with a message box like
  • Hence this release is of interest just for Windows users in that it fixes the issue.
  • Many thanks, Martin!
2018-08-02 0.5.0-β2
  • User Michal reported that bs1770gain v0.5.0-β1 is crashing when run with Opus samples.
  • As root cause we could identify that (deprecated) avcodec_decode_audio4() crashes when flushed with AV_CODEC_ID_OPUS.
  • As a workaround flushing the decoder is avoided now for AV_CODEC_ID_OPUS.
  • There's nothing preventing us from replacing deprectated API avcodec_decode_audio4() by the contemporary replacement API avcodec_send_packet()/avcodec_receive_frame (as already announced for several times. Of course, it's easier said then done ...)
  • Thanks again Michal!
2018-07-29 0.5.0-β1
  • Essentially this is a re-compilation against current FFmpeg. As it turned out bs100gain was showing unexpected behaviour when run with current (incompatible) FFmpeg libraries.
  • While at it we guarded bs1770gain against being run with incompatible FFmpeg and SoX libraries.
  • Fixed some bugs:
    • #881131: The bug was forced due to artifical test data faking zero channels: 
      peter@debian-9-32:~/msys64/bs1770gain$ ~/bs1770gain/bin/bs1770gain ./bug-881131-channel-underflow/poc -o output
analyzing ...
  [1/1] "poc": Error channel underflow (0 - should be 1 at min): ffsox_frame_reader_create() - "ffsox_frame_reader.c" (55).
Error creating frame reader: ffsox_frame_reader_new() - "ffsox_frame_reader.c" (132).
Error creating frame reader: ffsox_analyze() - "ffsox_analyze.c" (68).
Error gathering track statistics - "bs1770gain_tree.c" (152).
peter@debian-9-32:~/msys64/bs1770gain$ _
    • #881132: The bug was forced due to artifical test data faking a number of channels by far greater then the numer supported by FFmpeg: 
      peter@debian-9-32:~/msys64/bs1770gain$ ~/bs1770gain/bin/bs1770gain ./bug-881132-channel-overflow/poc -o output
analyzing ...
  [1/1] "poc": Error channel overflow (31 - should be 8 at max): ffsox_frame_reader_create() - "ffsox_frame_reader.c" (63).
Error creating frame reader: ffsox_frame_reader_new() - "ffsox_frame_reader.c" (132).
Error creating frame reader: ffsox_analyze() - "ffsox_analyze.c" (68).
Error gathering track statistics - "bs1770gain_tree.c" (152).
peter@debian-9-32:~/msys64/bs1770gain$ _
    • #883198: The bug was forced due to artifical test data fooling FFmpeg to come up with a zero codec id: 
      peter@debian-9-32:~/msys64/bs1770gain$ ~/bs1770gain/bin/bs1770gain ./bug-883198-missing-codec-id/poc -o output
analyzing ...
  [1/1] "poc": Error finding decoder: ffsox_frame_reader_create() - "ffsox_frame_reader.c" (48).
Error creating frame reader: ffsox_frame_reader_new() - "ffsox_frame_reader.c" (132).
Error creating frame reader: ffsox_analyze() - "ffsox_analyze.c" (68).
Error gathering track statistics - "bs1770gain_tree.c" (152).
peter@debian-9-32:~/msys64/bs1770gain$ _
  • Re-designed the dynamic loader module ("ffsox_dynload.c" vs. "ffsox_dynload2.c").
2017-01-10   Added a political statement to the top of this page.
2016-12-08 0.4.12 Added UTF-16 support to the Windows Console. Linux should not be affected and should have been worked all the time because being based on UTF-8. This development was triggered by Seongkyun (Andrei) Kim who is located in Korea and provided some testing.
2016-12-06   Thanks to Seongkyun (Andrei) Kim there is an introduction to bs1770gain in Korean language available at http://blog.naver.com/eqmaker/220879120285 and a manual at http://www.eqmaker.kr/public/BS1770GAIN_Manual_KOR-20161206.pdf.
2016-11-10   To all you great people out there in the US: Thank you for electing Donald Trump!
2016-08-13 0.4.11 Just recently a very talented guy who calls himself kevinlekiller (https://github.com/kevinlekiller/) approached me with a bunch of bugs he obviously had learned the hard way by using the tool (i.e. by not artificially testing it). But not just that, he also proposed a solution for each of the bugs: https://gist.github.com/kevinlekiller/62730fa5ddcf791107a723b1f235773e. This release mainly consists of his contributions.
  • Fixed ignoring the --audio=<n> option.
  • Fixed crashing with files containing more than 5 audio streams.
2016-07-18 0.4.10 Fixed writing xml escaped strings with the --xml option. Please note that bs1770gain is not officially supported on OSX even if it seems to build on OSX platforms and that it hence don't take into account unicode mapping anomalies between OSX and Linux/Windows (NFD/NFC). It will always output the unicode dialect common on the platform and hence the generated XML is not portable between OSX and Linux/Windows.
2016-03-16 0.4.9
  • In "ffsox_frame_convert.c", replaced constant ~0ll by ~0ull (sould fix #811955).
  • Replaced av_free_packet() by av_packet_unref() (should fix #810563).
2015-12-19 0.4.8
  • There's a new option --norm=<float> allowing to set the reference loudness to some value apart from -23.0 (EBU R128), -24.0 (ATSC A/85), or -18.0 (ReplayGain 2.0).
  • Loudness values are written to the output console with two places after the decimal point.
  • Regarding the Windows version, added some support for unicode paths (i.e. non-OEM).
2015-09-15 0.4.7 Fixed a serious bug regarding the -r option.
2015-09-12 0.4.6
  • There's a new option --xml for producing XML-output.
  • There's a new option --stereo. The effect is that down-mix to stereo only happens if requested. The old version always silently down-mixes to stereo which is fixed now.
  • FFmpeg has bumped their version numbers, i.e is not binary compatible to the old version. The new binary release now requires avutil-55, swresample-2, avcodec-57, and avformat-57.
2015-06-25 0.4.5 Various fixes mainly to make BS1770GAIN compile on various architectures.
2015-06-22 0.4.4
  • Fixed "stuttering" videos.
  • Thanks to Petter Reinholdtsen there is now an official BS1770GAIN package available on Debian. Read about Petter's plans regarding BS1770GAIN.
2015-06-15 0.4.3
  • Automake/Autoconf compatible source code distribution.
  • Several fixes.
2015-06-08 0.4.2 Fixed memory leaks.
2015-01-29 0.4.1 Several fixes.
2015-01-14 0.4.0
  • Integrated BS.1770 analysis into the finite state machine.
  • Added automatic TRACK and DISC tags extension.
  • Added --extension <extension> option.
  • Several fixes.
2015-01-08 0.3.2
  • Added another extension.
  • Several fixes.
2014-12-30 0.3.1 Minor fixes.
2014-12-23 0.3.0 Finite state machine for remuxing/transcoding.
2014-12-11 0.2.1
  • Fixed a critical bug breaking the whole program (thanks to Michal Šmucr).
  • Improved diagnostic of erroneous command line.
2014-12-07 0.2.0 Added experimental options.
2014-12-04 0.1.1
  • Compiled with -O2.
  • Slightly different error handling with getopt_long().
  • Added the FFmpeg and SoX shared objects / dynamic link libraries to the release.
2014-12-01 0.1.0 Initial release.

2. Introduction

Audio from different sources can be expected to be different loud and it would be nice to automatically adapt all these audio sources to the same loudness. Fortunately the ITU-R in their BS.1770 standard defines an algorithm which makes it possible to measure the loudness of a certain audio source. Based on the ITU-R BS.1770 measure several standards bodys defined what they think is the preferred loudness audio should normalize to, notably

BS1770GAIN implements the ITU-R BS.1770 loudness measurement algorithm and makes it accessable to a user in several ways as known from the EBU R128 standard, i.e.

The integrated loudness is the two phase gated measurement of the mean loudness as described by ITU-R BS.1770. All measures are described in detail by EBU R128.

On top of that BS1770GAIN provides to additional measures not related to loudness:

Besides measuring the loudness BS1770GAIN is also able to adapt it conformant with the above mentioned statndards. There are two ways to achieve this:

Following we describe in more detail how BS1770GAIN has to be customized.

3. Usage

3.1. Loudness Measurement

In the simplest case we want to analyze the (integrated) loudness of a track or, a bit more general, an album. Assuming the album is stored in some folder (in the following examples the folder is "~/2012_live_at_the_georgia_theatre") we may issue the following command: 

$ bs1770gain ~/2012_live_at_the_georgia_theatre
/home/home/2012_live_at_the_georgia_theatre
analyzing "2012_live_at_the_georgia_theatre" ...
  [1/3] "01_intro_like_i_am.mkv":
      integrated:  -16.2 LUFS / -6.8 LU
  [2/3] "02_good_one_coming_on.mkv":
      integrated:  -15.9 LUFS / -7.1 LU
  [3/3] "03_up_in_smoke.mkv":
      integrated:  -15.6 LUFS / -7.4 LU
  [ALBUM]:
      integrated:  -15.9 LUFS / -7.1 LU
done.
Immediatly BS1770GAIN gives us the (integrated) loudness of each track as well as of the whole album.

The figure behind the slash is the gain one has to apply in order to achieve a certain loudness. Which loudness to choose depends on the users preferences and there are several standards to choose from, noatbly EBU R128, ATSC A/85, and ReplayGain 2.0 (cf. above). BS1770GAIN silently assumes EBU R128. If we want to alter this we have to utilize the --atsc or --replaygain options, respectively. For example, if we want to normalize to ATSC A/85 we have to issue the command 

$ bs1770gain ~/2012_live_at_the_georgia_theatre --atsc
/home/home/2012_live_at_the_georgia_theatre
analyzing "2012_live_at_the_georgia_theatre" ...
  [1/3] "01_intro_like_i_am.mkv":
      integrated:  -16.2 LUFS / -7.8 LU
  [2/3] "02_good_one_coming_on.mkv":
      integrated:  -15.9 LUFS / -8.1 LU
  [3/3] "03_up_in_smoke.mkv":
      integrated:  -15.6 LUFS / -8.4 LU
  [ALBUM]:
      integrated:  -15.9 LUFS / -8.1 LU
done.

You may request XML output by means of the --xml option: 

$ bs1770gain ~/2012_live_at_the_georgia_theatre --xml
<bs1770gain>
  <album folder="2012_live_at_the_georgia_theatre">
    <track total="3" number="1" file="01_intro_like_i_am.mkv">
      <integrated lufs="-16.2" lu="-6.8" />
    </track>
    <track total="3" number="2" file="02_good_one_coming_on.mkv">
      <integrated lufs="-15.9" lu="-7.1" />
    </track>
    <track total="3" number="3" file="03_up_in_smoke.mkv">
      <integrated lufs="-15.6" lu="-7.4" />
    </track>
    <summary total="3">
      <integrated lufs="-15.9" lu="-7.1" />
    </summary>
  </album>
</bs1770gain>

In general, if we want to analyze properties out of intergrated loudness, maximum shortterm loudness, maximum momentary loudness, loudness range, maximum sample peak, or maximum true peak we have to choose the appropriate command line switches out of -i/--integrated, -s/--shortterm, -m/--momentary, -r/--range, -p/--samplepeak, and -t/--truepeak, respectivley. Assuming we're interested in all of these properties at once we have to issue following command: 

$ bs1770gain ~/2012_live_at_the_georgia_theatre -ismrpt
/home/home/2012_live_at_the_georgia_theatre
analyzing "2012_live_at_the_georgia_theatre" ...
  [1/3] "01_intro_like_i_am.mkv":
       integrated:  -16.2 LUFS / -6.8 LU
        shortterm:  -12.3 LUFS / -10.7 LU
        momentary:  -12.3 LUFS / -10.7 LU
            range:  4.9 LUFS
      sample peak:  -2.2 SPFS / 0.772912
        true peak:  -2.2 TPFS / 0.774780
  [2/3] "02_good_one_coming_on.mkv":
       integrated:  -15.9 LUFS / -7.1 LU
        shortterm:  -12.0 LUFS / -11.0 LU
        momentary:  -12.0 LUFS / -11.0 LU
            range:  5.9 LUFS
      sample peak:  -2.9 SPFS / 0.714886
        true peak:  -2.9 TPFS / 0.714886
  [3/3] "03_up_in_smoke.mkv":
       integrated:  -15.6 LUFS / -7.4 LU
        shortterm:  -12.3 LUFS / -10.7 LU
        momentary:  -12.3 LUFS / -10.7 LU
            range:  5.4 LUFS
      sample peak:  -2.8 SPFS / 0.726805
        true peak:  -2.8 TPFS / 0.726805
  [ALBUM]:
       integrated:  -15.9 LUFS / -7.1 LU
        shortterm:  -12.0 LUFS / -11.0 LU
        momentary:  -12.0 LUFS / -11.0 LU
            range:  5.3 LUFS
      sample peak:  -2.2 SPFS / 0.772912
        true peak:  -2.2 TPFS / 0.774780
done.

If we want to analyze just a short part of the files (say starting at 1 minute and lasting 30 seconds) we may issue the following command utilizing the -b/--begin and -d/--duration options: 

$ bs1770gain ~/2012_live_at_the_georgia_theatre -b 1:00 -d 30
/home/home/2012_live_at_the_georgia_theatre
analyzing "2012_live_at_the_georgia_theatre" ...
  [1/3] "01_intro_like_i_am.mkv":
      integrated:  -17.0 LUFS / -6.0 LU
  [2/3] "02_good_one_coming_on.mkv":
      integrated:  -15.4 LUFS / -7.6 LU
  [3/3] "03_up_in_smoke.mkv":
      integrated:  -16.0 LUFS / -7.0 LU
  [ALBUM]:
      integrated:  -16.1 LUFS / -6.9 LU
done.

3.2. Applying the Gain

With the help of BS1770GAIN we can adjust the loudness on the fly. There are two ways to achieve this:

In each case we have to instruct BS1770GAIN where to write the output files by means of the -o/--output switch which has to point to the output folder. If we want BS1770GAIN to really apply the gain and not just to write tags to the files we also have to supply the -a/--apply switch. Two examples follow in order to illustrate this.

The first example shows how to just write REPLAYGAIN tags to the output files. In this case we only have to supply the -o/--output switch: 

$ bs1770gain ~/2012_live_at_the_georgia_theatre -o ./test
/home/home/number-3/2012_live_at_the_georgia_theatre
analyzing "2012_live_at_the_georgia_theatre" ...
  [1/3] "01_intro_like_i_am.mkv":
      integrated:  -16.2 LUFS / -6.8 LU
  [2/3] "02_good_one_coming_on.mkv":
      integrated:  -15.9 LUFS / -7.1 LU
  [3/3] "03_up_in_smoke.mkv":
      integrated:  -15.6 LUFS / -7.4 LU
  [ALBUM]:
      integrated:  -15.9 LUFS / -7.1 LU
remuxing "2012_live_at_the_georgia_theatre" ...
  [1/3] "01_intro_like_i_am.mkv" ... done.
  [2/3] "02_good_one_coming_on.mkv" ... done.
  [3/3] "03_up_in_smoke.mkv" ... done.
done.

We can convince ourselves that there are indeed REPLAYGAIN tags written to the files and that the video and the audio streams are not altered. To that means we make use of the -l/--list switch: 

$ bs1770gain ./test/2012_live_at_the_georgia_theatre -l
./test/2012_live_at_the_georgia_theatre
Input #0, matroska,webm, from './test/2012_live_at_the_georgia_theatre/01_intro_like_i_am.mkv':
  Metadata:
    title           : Intro / Like I Am
    REPLAYGAIN_TRACK_GAIN: -6.81 LU
    CREATION_TIME   : 2013-02-09 13:41:04
    ARTIST          : Blackberry Smoke
    ALBUM           : Live At The Georgia Theatre
    YEAR            : 2012
    DISC            : 1/1
    track           : 1
    GENRE           : Rock
    REPLAYGAIN_ALBUM_GAIN: -7.05 LU
    REPLAYGAIN_ALGORITHM: ITU-R BS.1770
    REPLAYGAIN_REFERENCE_LOUDNESS: -23.00
    ENCODER         : Lavf56.15.101
  Duration: 00:05:15.36, start: 0.033000, bitrate: 7516 kb/s
    Stream #0:0: Video: mpeg2video (Main), yuv420p(tv, smpte170m), 720x480 [SAR 32:27 DAR 16:9], max. 8700 kb/s, SAR 186:157 DAR 279:157, 59.94 fps, 59.94 tbr, 1k tbn, 59.94 tbc (default)
    Stream #0:1: Audio: ac3, 48000 Hz, stereo, fltp, 448 kb/s (default)
Input #0, matroska,webm, from './test/2012_live_at_the_georgia_theatre/02_good_one_coming_on.mkv':
  Metadata:
    title           : Good One Coming On
    REPLAYGAIN_TRACK_GAIN: -7.05 LU
    CREATION_TIME   : 2013-02-09 13:46:45
    ARTIST          : Blackberry Smoke
    ALBUM           : Live At The Georgia Theatre
    YEAR            : 2012
    DISC            : 1/1
    track           : 2
    GENRE           : Rock
    REPLAYGAIN_ALBUM_GAIN: -7.05 LU
    REPLAYGAIN_ALGORITHM: ITU-R BS.1770
    REPLAYGAIN_REFERENCE_LOUDNESS: -23.00
    ENCODER         : Lavf56.15.101
  Duration: 00:03:37.27, start: 0.033000, bitrate: 7741 kb/s
    Stream #0:0: Video: mpeg2video (Main), yuv420p(tv, smpte170m), 720x480 [SAR 32:27 DAR 16:9], max. 8700 kb/s, SAR 186:157 DAR 279:157, 59.94 fps, 59.94 tbr, 1k tbn, 59.94 tbc (default)
    Stream #0:1: Audio: ac3, 48000 Hz, stereo, fltp, 448 kb/s (default)
Input #0, matroska,webm, from './test/2012_live_at_the_georgia_theatre/03_up_in_smoke.mkv':
  Metadata:
    title           : Up In Smoke
    REPLAYGAIN_TRACK_GAIN: -7.37 LU
    CREATION_TIME   : 2013-02-09 10:09:16
    ARTIST          : Blackberry Smoke
    ALBUM           : Live At The Georgia Theatre
    YEAR            : 2012
    DISC            : 1/1
    track           : 3
    GENRE           : Rock
    REPLAYGAIN_ALBUM_GAIN: -7.05 LU
    REPLAYGAIN_ALGORITHM: ITU-R BS.1770
    REPLAYGAIN_REFERENCE_LOUDNESS: -23.00
    ENCODER         : Lavf56.15.101
  Duration: 00:03:33.77, start: 0.033000, bitrate: 8151 kb/s
    Stream #0:0: Video: mpeg2video (Main), yuv420p(tv, smpte170m), 720x480 [SAR 32:27 DAR 16:9], max. 8700 kb/s, SAR 186:157 DAR 279:157, 59.94 fps, 59.94 tbr, 1k tbn, 59.94 tbc (default)
    Stream #0:1: Audio: ac3, 48000 Hz, stereo, fltp, 448 kb/s (default)
The second example deals with really applying the gain. For that order we not only have to supply the -o/--output switch but also the -a/--apply switch: 
$ bs1770gain ~/2012_live_at_the_georgia_theatre -ao ./test
/home/home/number-3/2012_live_at_the_georgia_theatre
analyzing "2012_live_at_the_georgia_theatre" ...
  [1/3] "01_intro_like_i_am.mkv":
      integrated:  -16.2 LUFS / -6.8 LU
  [2/3] "02_good_one_coming_on.mkv":
      integrated:  -15.9 LUFS / -7.1 LU
  [3/3] "03_up_in_smoke.mkv":
      integrated:  -15.6 LUFS / -7.4 LU
  [ALBUM]:
      integrated:  -15.9 LUFS / -7.1 LU
transcoding "2012_live_at_the_georgia_theatre" ...
  [1/3] "01_intro_like_i_am.mkv" ... done.
  [2/3] "02_good_one_coming_on.mkv" ... done.
  [3/3] "03_up_in_smoke.mkv" ... done.
done.

An obvious difference to the previous example is that BS1770GAIN now uses the term transcoding instead of remuxing. The reason for that is that the streams are now altered and no REPLAYGAIN-tags appear if we make the contents of the transcoded files visible by means of the -l/--list switch: 

$ bs1770gain ./test/2012_live_at_the_georgia_theatre -l
./test/2012_live_at_the_georgia_theatre
Input #0, matroska,webm, from './test/2012_live_at_the_georgia_theatre/01_intro_like_i_am.mkv':
  Metadata:
    title           : Intro / Like I Am
    GENRE           : Rock
    CREATION_TIME   : 2013-02-09 13:41:04
    ARTIST          : Blackberry Smoke
    ALBUM           : Live At The Georgia Theatre
    YEAR            : 2012
    DISC            : 1/1
    track           : 1
    ENCODER         : Lavf56.15.101
  Duration: 00:05:16.87, start: 0.033000, bitrate: 8626 kb/s
    Stream #0:0: Video: mpeg2video (Main), yuv420p(tv, smpte170m), 720x480 [SAR 32:27 DAR 16:9], max. 8700 kb/s, SAR 186:157 DAR 279:157, 59.94 fps, 59.94 tbr, 1k tbn, 59.94 tbc (default)
    Stream #0:1: Audio: flac, 48000 Hz, stereo, s32 (24 bit) (default)
Input #0, matroska,webm, from './test/2012_live_at_the_georgia_theatre/02_good_one_coming_on.mkv':
  Metadata:
    title           : Good One Coming On
    GENRE           : Rock
    CREATION_TIME   : 2013-02-09 13:46:45
    ARTIST          : Blackberry Smoke
    ALBUM           : Live At The Georgia Theatre
    YEAR            : 2012
    DISC            : 1/1
    track           : 2
    ENCODER         : Lavf56.15.101
  Duration: 00:03:38.77, start: 0.033000, bitrate: 8827 kb/s
    Stream #0:0: Video: mpeg2video (Main), yuv420p(tv, smpte170m), 720x480 [SAR 32:27 DAR 16:9], max. 8700 kb/s, SAR 186:157 DAR 279:157, 59.94 fps, 59.94 tbr, 1k tbn, 59.94 tbc (default)
    Stream #0:1: Audio: flac, 48000 Hz, stereo, s32 (24 bit) (default)
Input #0, matroska,webm, from './test/2012_live_at_the_georgia_theatre/03_up_in_smoke.mkv':
  Metadata:
    title           : Up In Smoke
    GENRE           : Rock
    CREATION_TIME   : 2013-02-09 10:09:16
    ARTIST          : Blackberry Smoke
    ALBUM           : Live At The Georgia Theatre
    YEAR            : 2012
    DISC            : 1/1
    track           : 3
    ENCODER         : Lavf56.15.101
  Duration: 00:03:35.27, start: 0.033000, bitrate: 9266 kb/s
    Stream #0:0: Video: mpeg2video (Main), yuv420p(tv, smpte170m), 720x480 [SAR 32:27 DAR 16:9], max. 8700 kb/s, SAR 186:157 DAR 279:157, 59.94 fps, 59.94 tbr, 1k tbn, 59.94 tbc (default)
    Stream #0:1: Audio: flac, 48000 Hz, stereo, s32 (24 bit) (default)

The most important observation is that the audio stream now is a 24 bit FLAC and no longer an AC3.

It may happen that it is not appropriate to base the gain on the measurement of the integrated loudness but insteed on the maximum shorterm loudness or on the maximum momentary loudness. For that means there is the -u/--use switch which has to be supplied with the method to use, i.e. integrated, shorterm, or momentary. The following illustrates this: 

$ bs1770gain ~/2012_live_at_the_georgia_theatre -o ./test -u shortterm
/home/home/number-3/2012_live_at_the_georgia_theatre
analyzing "2012_live_at_the_georgia_theatre" ...
  [1/3] "01_intro_like_i_am.mkv":
      shortterm:  -12.3 LUFS / -10.7 LU
  [2/3] "02_good_one_coming_on.mkv":
      shortterm:  -12.0 LUFS / -11.0 LU
  [3/3] "03_up_in_smoke.mkv":
      shortterm:  -12.3 LUFS / -10.7 LU
  [ALBUM]:
      shortterm:  -12.0 LUFS / -11.0 LU
remuxing "2012_live_at_the_georgia_theatre" ...
  [1/3] "01_intro_like_i_am.mkv" ... done.
  [2/3] "02_good_one_coming_on.mkv" ... done.
  [3/3] "03_up_in_smoke.mkv" ... done.
done.

3.3. Experimental Options

We can imagine the ITU-R BS.1770 measurement device as a blackbox where time after time portions of the audio with the same length

Such portions of audio are called a block. We assume that at a given time at least one audio block is inside the measurement device, but in general there are more than one are there.

The measurement device does some sophisticated calculation on the audio blocks currently inside with the loudness as the result. We don't want to go into all the details here but it should be clear that the result depends at least on the following:

EBU R128 defines two such measurement devices,

The momentary device has the following properties:

wheras the shorttime device has the following: After all we can calculate 6 measures from the two blocks, two of them are non-standard:

This gives rise to a variety of possible parameters if one takes into account that it is possible to customize measurement devices themselfs (cf. "experimental options" under "command line syntax" below).

Finally we give an example on how to RG tag with the non-standard measure shortterm mean loudness: 

$ ./bs1770gain ~/2012_live_at_the_georgia_theatre -o ./test -u shortterm-mean
/home/home/2012_live_at_the_georgia_theatre
analyzing "2012_live_at_the_georgia_theatre" ...
  [1/3] "01_intro_like_i_am.mkv":         
      shortterm mean:  -16.2 LUFS / -6.8 LU
  [2/3] "02_good_one_coming_on.mkv":         
      shortterm mean:  -16.0 LUFS / -7.0 LU
  [3/3] "03_up_in_smoke.mkv":         
      shortterm mean:  -15.6 LUFS / -7.4 LU
  [ALBUM]:
      shortterm mean:  -16.0 LUFS / -7.0 LU
remuxing "2012_live_at_the_georgia_theatre" ...
  [1/3] "01_intro_like_i_am.mkv" ... done.
  [2/3] "02_good_one_coming_on.mkv" ... done.
  [3/3] "03_up_in_smoke.mkv" ... done.
done.

4. Command Line Syntax

$ bs1770gain -h
BS1770GAIN 0.4.8, Copyright (C) Peter Belkner 2014-2015.
http://bs1770gain.sourceforge.net/

Usage:  bs1770gain [options] <file/dir> [<file/dir> ...]

Options:
 -h,--help:  print this message and exit
 -i,--integrated:  calculate integrated loudness
 -s,--shorterm:  calculate maximum shortterm loudness
 -m,--momentary:  claculate maximum momentary loudness
 -r,--range:  calculate loudness range
 -p,--samplepeak:  calculate maximum sample peak
 -t,--truepeak:  calculate maximum true peak
 -b <timestamp>,--begin <timestamp>:  begin decoding at
   timestamp (in microseconds, format: hh:mm:ss.mus)
 -d <duration>,--duration <duration>:  let decoding
   last duration (in microseconds, format: hh:mm:ss.mus)
 -u <method>,--use <method>:  base replay gain calculation
   on method (with respect to the -a/--apply and -o/--output
   options),
   methods:  "integrated" (default), "shortterm", or
   "momentary"
   experimental methods:  "momentary-mean" (same as
   "integrated"), "momentary-maximum" (same as "momentary"),
   "shortterm-mean", or "shortterm-maximum" (same as
   "shortterm")
 -a:  apply the EBU/ATSC/RG album gain to the output
   (in conjunction with the -o/--output option)
 -o <folder>,--output <folder>:  write RG tags
   or apply the EBU/ATSC/RG gain, respectively,
   and output to folder
 -f <file>,--file <file>:  write analysis to file
 -x,--extensions:  enable following extensions/defaults:
   1) rename files according to TITLE tag
   2) read metadata from per-folder CSV file "folder.csv"
   3) copy file "folder.jpg" from source to destination
      folder
   4) automatically add the TRACK and DISC tags
   5) calculate maximum true peak
   6) convert to stereo
 -l,--list:  print FFmpeg format/stream information
 --ebu:  calculate replay gain according to EBU R128
   (-23.0 LUFS, default)
 --atsc:  calculate replay gain according to ATSC A/85
   (-24.0 LUFS)
 --replaygain:  calculate replay gain according to
   ReplayGain 2.0 (-18.0 LUFS)
 --track-tags:  write track tags
 --album-tags:  write album tags
 --unit <unit>:  write tags with <unit>
 --apply <q>:  apply the EBU/ATSC/RG gain to the output
   (in conjunction with the -o/--output option),
   q=0.0 (album gain) ... 1.0 (track gain),
   default:  0.0 (album gain)
 --audio <index>:  select audio index (corresponds to
   [0:<index>] in FFmpeg listing, cf. -l/--list option)
 --video <index>:  select video index (corresponds to
   [0:<index>] in FFmpeg listing, cf. -l/--list option)
 --stereo:  convert to stereo
 --drc <float>:  set AC3 dynamic range compression (DRC)
 --extension <extension>:  enable extension out of
   "rename":  rename files according to TITLE tag
   "csv":  read metadata from per-folder CSV file "folder.csv"
   "jpg":  copy file "folder.jpg" from source to destination
      folder
   "tags":  automatically add the TRACK and DISC tags
 --format <format>:  convert to format
 --loglevel <level>:  set loglevel,
   level:  "quiet", "panic", "fatal", "error", "warning",
   "info", "verbose", "debug"
 --xml:  print results in xml format
 --time:  print out duration of program invocation
 --norm <float>:  norm loudness to float.

Experimental options:
1) momentary block
 --momentary-mean:  calculate mean loudness based on
   momentary block (same as --integrated)
 --momentary-maximum:  calculate maximum loudness based
   on momentary block (same as --momentary)
 --momentary-range:  calculate loudness range based on
   momentary block
 --momentary-length <ms>:  length of momentary block
   in milliseconds (default: 400)
 --momentary-overlap <percent>:  overlap of momentary
   block in percent (default: 75)
 --momentary-mean-gate <gate>:  silence gate for mean
   measurement of momentary block (default: -10.0)
 --momentary-range-gate <gate>:  silence gate for range
   measurement of momentary block (default: -20.0)
 --momentary-range-lower-bound <float>:  lower bound for
   range measurement of momentary block (default: 0.1)
 --momentary-range-upper-bound <float>:  upper bound for
   range measurement of momentary block (default: 0.95)
2) shortterm block
 --shortterm-mean:  calculate mean loudness based on
   shortterm block
 --shortterm-maximum:  calculate maximum loudness based
   on shortterm block (same as --shortterm)
 --shortterm-range:  calculate loudness range based on
   shortterm block (same as --range)
 --shortterm-length <ms>:  length of shortterm block
   in milliseconds (default: 3000)
 --shortterm-overlap <percent>:  overlap of shortterm
   block in percent (default: 67)
 --shortterm-mean-gate <gate>:  silence gate for mean
   measurement of shortterm block (default: -10.0)
 --shortterm-range-gate <gate>:  silence gate for range
   measurement of shortterm block (default: -20.0)
 --shortterm-range-lower-bound <float>:  lower bound for
   range measurement of shortterm block (default: 0.1)
 --shortterm-range-upper-bound <float>:  upper bound for
   range measurement of shortterm block (default: 0.95)

Command line arguments may appear in any order.

5. Test Cases

Results for the EBU R128 test vector: