[FFmpeg-trac] #4823(undetermined:new): Conversion from DTS/DTS-MA to AC3 results in 2 channels instead of 6

[FFmpeg]

#4823: Conversion from DTS/DTS-MA to AC3 results in 2 channels instead of 6
-------------------------------------+-------------------------------------
             Reporter:  JohnGalt     |                    Owner:
                 Type:  defect       |                   Status:  new
             Priority:  normal       |                Component:
              Version:  git-master   |  undetermined
             Keywords:  ac3 dts      |               Resolution:
             Blocking:               |               Blocked By:
Analyzed by developer:  0            |  Reproduced by developer:  0
-------------------------------------+-------------------------------------

Comment (by JohnGalt):

 You can download the sample from here:

 http://www.demo-world.eu/download-2d-trailers/?file
 =dts_hd_master_audio_sound_check_7_1_lossless-
 DWEU.mkv&pic=dts_hd_master_audio_sound_check_7_1_lossless.jpg

 and click on the mage between the two adds.  This is simplified but the
 result is the same. You get DTSMA with channels(s): 2 channels,
 Channel(s)_Original: 8 channels/6 chnanels and then AC3 2 channel stereo
 and aac 2 channel stereo.

 Given that I'm explicit about the mappings now I would have expected the
 AC3 track to be 6 channel converted from the DTS-MA track and the aac
 track to be 2 channel converted from the DTS-MA track.

 ffmpeg -probesize 5G -analyzeduration 5G -i
 "dts_hd_master_audio_sound_check_7_1_lossless-DWEU.mkv" -map 0:0 -map 0:1
 -map 0:1 -map 0:1 -c:v copy -c:a:0 copy -c:a:1 ac3 -ac:1 6 -ab:1 448k
 -ar:1 48000 -c:a:2 aac -ac:2 2 -ab:2 192k -ar:2 48000 -scodec copy -strict
 experimental -f mp4 -movflags faststart "dts hd master audio sound check 7
 1 lossless-DWEU.m4v"
 ffmpeg version N-74737-g1acd631 Copyright (c) 2000-2015 the FFmpeg
 developers
   built with gcc 4.9.3 (GCC)
   configuration: --enable-gpl --enable-version3 --disable-w32threads
 --enable-avisynth --enable-bzlib --enable-fontconfig --enable-frei0r
 --enable-gnutls --enable-iconv --enable-libass --enable-libbluray
 --enable-libbs2b --enable-libcaca --enable-libdcadec --enable-libfreetype
 --enable-libgme --enable-libgsm --enable-libilbc --enable-libmodplug
 --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb
 --enable-libopenjpeg --enable-libopus --enable-librtmp --enable-
 libschroedinger --enable-libsoxr --enable-libspeex --enable-libtheora
 --enable-libtwolame --enable-libvidstab --enable-libvo-aacenc --enable-
 libvo-amrwbenc --enable-libvorbis --enable-libvpx --enable-libwavpack
 --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxavs
 --enable-libxvid --enable-lzma --enable-decklink --enable-zlib
   libavutil      54. 31.100 / 54. 31.100
   libavcodec     56. 59.100 / 56. 59.100
   libavformat    56. 40.101 / 56. 40.101
   libavdevice    56.  4.100 / 56.  4.100
   libavfilter     5. 40.100 /  5. 40.100
   libswscale      3.  1.101 /  3.  1.101
   libswresample   1.  2.101 /  1.  2.101
   libpostproc    53.  3.100 / 53.  3.100
 Input #0, matroska,webm, from 'd:\downloads
 \dts_hd_master_audio_sound_check_7_1_lossless-DWEU.mkv':
   Metadata:
     encoder         : libebml v1.3.0 + libmatroska v1.4.1
     creation_time   : 2015-04-06 09:50:07
   Duration: 00:04:18.13, start: 0.000000, bitrate: 7533 kb/s
     Stream #0:0(eng): Video: h264 (High), yuv420p, 1920x1080, SAR 1:1 DAR
 16:9, 23.98 fps, 23.98 tbr, 1k tbn, 47.95 tbc (default)
     Stream #0:1(eng): Audio: dts (DTS-HD MA), 48000 Hz, 5.1(side), fltp
 (default)
 [mp4 @ 0000000005890920] Codec for stream 0 does not use global headers
 but container format requires global headers
 [mp4 @ 0000000005890920] Codec for stream 1 does not use global headers
 but container format requires global headers
 [mp4 @ 0000000005890920] track 1: codec frame size is not set
 Output #0, mp4, to 'd:\downloads\dts hd master audio sound check 7 1
 lossless-DWEU.m4v':
   Metadata:
     Name            : dts hd master audio sound check 7 1 lossless-DWEU
     title           : dts hd master audio sound check 7 1 lossless-DWEU
     encoder         : Lavf56.40.101
     Stream #0:0(eng): Video: h264 ([33][0][0][0] / 0x0021), yuv420p,
 1920x1080 [SAR 1:1 DAR 16:9], q=2-31, 23.98 fps, 23.98 tbr, 16k tbn, 1k
 tbc (default)
     Stream #0:1(eng): Audio: dts ([169][0][0][0] / 0x00A9), 48000 Hz,
 5.1(side) (default)
     Stream #0:2(eng): Audio: ac3 ([165][0][0][0] / 0x00A5), 48000 Hz,
 stereo, fltp, 192 kb/s (default)
     Metadata:
       encoder         : Lavc56.59.100 ac3
     Stream #0:3(eng): Audio: aac ([64][0][0][0] / 0x0040), 48000 Hz,
 5.1(side), fltp, 128 kb/s (default)
     Metadata:
       encoder         : Lavc56.59.100 aac
 Stream mapping:
   Stream #0:0 -> #0:0 (copy)
   Stream #0:1 -> #0:1 (copy)
   Stream #0:1 -> #0:2 (dts (dca) -> ac3 (native))
   Stream #0:1 -> #0:3 (dts (dca) -> aac (native))
 Press [q] to stop, [?] for help
 [mp4 @ 0000000005890920] Starting second pass: moving the moov atom to the
 beginning of the file
 frame= 6188 fps=235 q=-1.0 Lsize=  247215kB time=00:04:18.13
 bitrate=7845.4kbits/s
 video:161764kB audio:84700kB subtitle:0kB other streams:0kB global
 headers:0kB muxing overhead: 0.304666%

--
Ticket URL: <https://trac.ffmpeg.org/ticket/4823#comment:7>
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