Xtykutl

I have a question involving multiple audio languages on HLS with FFMPEG.

I'm currently using the following command to mux a transport stream with multiple audio languages into an HLS stream with a master playlist:

ffmpeg -re -i $INPUT_URL -map 0:v -c:v copy -map 0:a -c:a copy -f hls -hls_time 6 -hls_list_size 10 -hls_flags delete_segments+program_date_time -hls_segment_filename "$FULL_OUTPUT_FOLDER/stream_%v_%d.ts" -var_stream_map "v:0,agroup:groupname a:0,agroup:groupname a:1,agroup:groupname a:2,agroup:groupname a:3,agroup:groupname" -master_pl_name master.m3u8 $FULL_OUTPUT_FOLDER/stream-%v.m3u8 

The output of this command looks like this:

ffmpeg version 4.0.3-1~16.04.york0 Copyright (c) 2000-2018 the FFmpeg developers

  built with gcc 5.4.0 (Ubuntu 5.4.0-6ubuntu1~16.04.10) 20160609

  configuration: --prefix=/usr --extra-version='1~16.04.york0' --toolchain=hardened --libdir=/usr/lib/x86_64-linux-gnu --incdir=/usr/include/x86_64-linux-gnu --arch=amd64 --enable-gpl --disable-stripping --enable-avresample --disable-filter=resample --enable-avisynth --enable-gnutls --enable-ladspa --enable-libaom --enable-libass --enable-libbluray --enable-libbs2b --enable-libcaca --enable-libcdio --enable-libcodec2 --enable-libflite --enable-libfontconfig --enable-libfreetype --enable-libfribidi --enable-libgme --enable-libgsm --enable-libjack --enable-libmp3lame --enable-libmysofa --enable-libopenjpeg --enable-libopenmpt --enable-libopus --enable-libpulse --enable-librsvg --enable-librubberband --enable-libshine --enable-libsnappy --enable-libsoxr --enable-libspeex --enable-libssh --enable-libtheora --enable-libtwolame --enable-libvidstab --enable-libvorbis --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx265 --enable-libxml2 --enable-libxvid --enable-libzmq --enable-libzvbi --enable-lv2 --enable-omx --enable-openal --enable-opengl --enable-sdl2 --enable-libdc1394 --enable-libdrm --enable-libiec61883 --enable-chromaprint --enable-frei0r --enable-libopencv --enable-libx264 --enable-shared

  libavutil      56. 14.100 / 56. 14.100

  libavcodec     58. 18.100 / 58. 18.100

  libavformat    58. 12.100 / 58. 12.100

  libavdevice    58.  3.100 / 58.  3.100

  libavfilter     7. 16.100 /  7. 16.100

  libavresample   4.  0.  0 /  4.  0.  0

  libswscale      5.  1.100 /  5.  1.100

  libswresample   3.  1.100 /  3.  1.100

  libpostproc    55.  1.100 / 55.  1.100

[mpegts @ 0x55c8cb7fee40] start time for stream 5 is not set in estimate_timings_from_pts

[mpegts @ 0x55c8cb7fee40] start time for stream 6 is not set in estimate_timings_from_pts                                                                                          

[mpegts @ 0x55c8cb7fee40] start time for stream 7 is not set in estimate_timings_from_pts                                                                                          

Input #0, mpegts, from '/home/user/Videos/output/example.ts':

  Duration: 00:37:50.26, start: 1.498667, bitrate: 1257 kb/s

  Program 1 

    Metadata:

      service_name    : example

      service_provider: FFmpeg

    Stream #0:0[0x100]: Video: h264 (High) ([27][0][0][0] / 0x001B), yuv420p(progressive), 696x572 [SAR 64:45 DAR 3712:2145], 25 fps, 25 tbr, 90k tbn, 50 tbc

    Stream #0:1[0x101](eng): Audio: aac (LC) ([15][0][0][0] / 0x000F), 48000 Hz, stereo, fltp, 159 kb/s

    Stream #0:2[0x102](fra): Audio: aac (LC) ([15][0][0][0] / 0x000F), 48000 Hz, stereo, fltp, 126 kb/s

    Stream #0:3[0x103](ita): Audio: aac (LC) ([15][0][0][0] / 0x000F), 48000 Hz, stereo, fltp, 132 kb/s

    Stream #0:4[0x104](eng): Audio: aac (LC) ([15][0][0][0] / 0x000F), 48000 Hz, stereo, fltp, 132 kb/s

    Stream #0:5[0x105](eng): Subtitle: dvb_subtitle ([6][0][0][0] / 0x0006)

    Stream #0:6[0x106](fra): Subtitle: dvb_subtitle ([6][0][0][0] / 0x0006)

    Stream #0:7[0x107](deu): Subtitle: dvb_subtitle ([6][0][0][0] / 0x0006)

[hls @ 0x55c8cb834980] Opening '/var/www/html/live/stream_0_0.ts' for writing

[hls @ 0x55c8cb834980] Opening '/var/www/html/live/stream_1_0.ts' for writing

[hls @ 0x55c8cb834980] Opening '/var/www/html/live/stream_2_0.ts' for writing

[hls @ 0x55c8cb834980] Opening '/var/www/html/live/stream_3_0.ts' for writing

[hls @ 0x55c8cb834980] Opening '/var/www/html/live/stream_4_0.ts' for writing

[mpegts @ 0x55c8cb880380] frame size not set

[mpegts @ 0x55c8cb882040] frame size not set                                                                                                                                       

[mpegts @ 0x55c8cb8837c0] frame size not set                                                                                                                                       

[mpegts @ 0x55c8cb885280] frame size not set                                                                                                                                       

Output #0, hls, to '/var/www/html/live/stream-%v.m3u8':

  Metadata:

    encoder         : Lavf58.12.100

    Stream #0:0: Video: h264 (High) ([27][0][0][0] / 0x001B), yuv420p(progressive), 696x572 [SAR 64:45 DAR 3712:2145], q=2-31, 25 fps, 25 tbr, 90k tbn, 25 tbc

    Stream #0:1(eng): Audio: aac (LC) ([15][0][0][0] / 0x000F), 48000 Hz, stereo, fltp, 159 kb/s

    Stream #0:2(fra): Audio: aac (LC) ([15][0][0][0] / 0x000F), 48000 Hz, stereo, fltp, 126 kb/s

    Stream #0:3(ita): Audio: aac (LC) ([15][0][0][0] / 0x000F), 48000 Hz, stereo, fltp, 132 kb/s

    Stream #0:4(eng): Audio: aac (LC) ([15][0][0][0] / 0x000F), 48000 Hz, stereo, fltp, 132 kb/s

Stream mapping:

  Stream #0:0 -> #0:0 (copy)

  Stream #0:1 -> #0:1 (copy)

  Stream #0:2 -> #0:2 (copy)

  Stream #0:3 -> #0:3 (copy)

  Stream #0:4 -> #0:4 (copy)

Press [q] to stop, [?] for help

[hls @ 0x55c8cb834980] Opening '/var/www/html/live/stream_1_1.ts' for writing    

[hls @ 0x55c8cb834980] Opening '/var/www/html/live/stream-1.m3u8.tmp' for writing

[hls @ 0x55c8cb834980] Opening '/var/www/html/live/stream_2_1.ts' for writing

[hls @ 0x55c8cb834980] Opening '/var/www/html/live/stream-2.m3u8.tmp' for writing

[hls @ 0x55c8cb834980] Opening '/var/www/html/live/stream_3_1.ts' for writing

[hls @ 0x55c8cb834980] Opening '/var/www/html/live/stream-3.m3u8.tmp' for writing

[hls @ 0x55c8cb834980] Opening '/var/www/html/live/stream_4_1.ts' for writing

[hls @ 0x55c8cb834980] Opening '/var/www/html/live/stream-4.m3u8.tmp' for writing

[hls @ 0x55c8cb834980] Opening '/var/www/html/live/stream_1_2.ts' for writing   

[hls @ 0x55c8cb834980] Opening '/var/www/html/live/stream-1.m3u8.tmp' for writing

[hls @ 0x55c8cb834980] Opening '/var/www/html/live/stream_2_2.ts' for writing

[hls @ 0x55c8cb834980] Opening '/var/www/html/live/stream-2.m3u8.tmp' for writing

[hls @ 0x55c8cb834980] Opening '/var/www/html/live/stream_3_2.ts' for writing

[hls @ 0x55c8cb834980] Opening '/var/www/html/live/stream-3.m3u8.tmp' for writing

[hls @ 0x55c8cb834980] Opening '/var/www/html/live/stream_4_2.ts' for writing

[hls @ 0x55c8cb834980] Opening '/var/www/html/live/stream-4.m3u8.tmp' for writing

[hls @ 0x55c8cb834980] Opening '/var/www/html/live/stream_0_1.ts' for writing   

[hls @ 0x55c8cb834980] Opening '/var/www/html/live/stream-0.m3u8.tmp' for writing

[hls @ 0x55c8cb834980] Opening '/var/www/html/live/master.m3u8' for writing

[hls @ 0x55c8cb834980] Opening '/var/www/html/live/stream_1_3.ts' for writing   

[hls @ 0x55c8cb834980] Opening '/var/www/html/live/stream-1.m3u8.tmp' for writing

The master playlist that's being output by this command looks like this:

#EXTM3U

#EXT-X-VERSION:3

#EXT-X-MEDIA:TYPE=AUDIO,GROUP-ID="group_groupname",NAME="audio_0",DEFAULT=YES,URI="stream-1.m3u8"

#EXT-X-MEDIA:TYPE=AUDIO,GROUP-ID="group_groupname",NAME="audio_0",DEFAULT=YES,URI="stream-2.m3u8"

#EXT-X-MEDIA:TYPE=AUDIO,GROUP-ID="group_groupname",NAME="audio_0",DEFAULT=YES,URI="stream-3.m3u8"

#EXT-X-MEDIA:TYPE=AUDIO,GROUP-ID="group_groupname",NAME="audio_0",DEFAULT=YES,URI="stream-4.m3u8"

#EXT-X-STREAM-INF:BANDWIDTH=174900,RESOLUTION=696x572,AUDIO="group_groupname"

stream-0.m3u8



#EXT-X-STREAM-INF:BANDWIDTH=174900,CODECS="mp4a.40.2",AUDIO="group_groupname"

stream-1.m3u8



#EXT-X-STREAM-INF:BANDWIDTH=174900,CODECS="mp4a.40.2",AUDIO="group_groupname"

stream-2.m3u8



#EXT-X-STREAM-INF:BANDWIDTH=174900,CODECS="mp4a.40.2",AUDIO="group_groupname"

stream-3.m3u8



#EXT-X-STREAM-INF:BANDWIDTH=174900,CODECS="mp4a.40.2",AUDIO="group_groupname"

stream-4.m3u8

While this does seem to work with VLC, I need the EXT-X-MEDIA:TYPE tag to contain the LANGUAGE property. (the player I'm working with uses it to parse the audio tracks' language) I can't figure out how to do that based on the documentation I've found.

Could anyone help me with this?

Thanks!

After looking at the source code, I found out that this is simply not supported (yet?)

In the code you can find the following functions:

[libavformat/hlsenc.c] create_master_playlist

[libavformat/hlsplaylist.c] ff_hls_write_audio_rendition

When looking at these implementations, you can see that the LANGUAGE attribute is never actually being output unfortunately.

So that means I'll have to find an alternative way to accomplish this.