[FFmpeg-trac] #4382(undetermined:new): Incorrect channel mapping when encoding dca/dts stream (Front C -> Front R)

FFmpeg trac at avcodec.org
Sat Mar 21 18:02:55 CET 2015


#4382: Incorrect channel mapping when encoding dca/dts stream (Front C -> Front R)
-------------------------------------+-------------------------------------
             Reporter:  Drag0nFly    |                     Type:  defect
               Status:  new          |                 Priority:  normal
            Component:               |                  Version:  2.6
  undetermined                       |               Blocked By:
             Keywords:  dts dca      |  Reproduced by developer:  0
  channel mapping                    |
             Blocking:               |
Analyzed by developer:  0            |
-------------------------------------+-------------------------------------
 Summary of the bug:
 =============

 When encoding to 5.1 DTS, the center channel is mapped to the right
 speaker. Issue verified with v2.6.0 & v2.6.1 on OSX, as well as a custom-
 built version from git (N-67986-g79f77ce) on Linux (in an attempt to rule
 out any recent regression.)

 The same input file has been tested on both systems encoding to
 5.1-channel AC3/Dolby Digital, and the channel placements are correct. So
 the decoding stage is working properly, the encoding stage is not.

 How to reproduce:

 Process any file with a DTS core (1.5Mbps) track from dts->dts/dca. In my
 case I used a volume adjustment (as the source was not 0dBFS). I doubt if
 this makes a difference, however.

 $ ffmpeg -i <input>.mkv -map 0 -c:v:0 copy -c:a:0 dts -strict -2 -af
 volume=+5.6dB -c:s copy <output>.mkv


 FFmpeg version info:
 =============

 OSX (version obtained from Homebrew): ffmpeg version 2.6.1 Copyright (c)
 2000-2015 the FFmpeg developers
   built with Apple LLVM version 6.0 (clang-600.0.57) (based on LLVM
 3.5svn)
   configuration: --prefix=/usr/local/Cellar/ffmpeg/2.6.1 --enable-shared
 --enable-pthreads --enable-gpl --enable-version3 --enable-hardcoded-tables
 --enable-avresample --cc=clang --host-cflags= --host-ldflags= --enable-
 libx264 --enable-libmp3lame --enable-libvo-aacenc --enable-libxvid
 --enable-vda
   libavutil      54. 20.100 / 54. 20.100
   libavcodec     56. 26.100 / 56. 26.100
   libavformat    56. 25.101 / 56. 25.101
   libavdevice    56.  4.100 / 56.  4.100
   libavfilter     5. 11.102 /  5. 11.102
   libavresample   2.  1.  0 /  2.  1.  0
   libswscale      3.  1.101 /  3.  1.101
   libswresample   1.  1.100 /  1.  1.100
   libpostproc    53.  3.100 / 53.  3.100


 Linux: ffmpeg version N-67986-g79f77ce Copyright (c) 2000-2014 the FFmpeg
 developers
   built on Nov 25 2014 12:44:58 with gcc 4.7 (Ubuntu/Linaro
 4.7.3-1ubuntu1)
   configuration: --prefix=/usr/local --enable-nonfree --enable-gpl
 --enable-libx264 --enable-libmp3lame --enable-libvorbis
   libavutil      54. 15.100 / 54. 15.100
   libavcodec     56. 13.100 / 56. 13.100
   libavformat    56. 15.100 / 56. 15.100
   libavdevice    56.  3.100 / 56.  3.100
   libavfilter     5.  2.103 /  5.  2.103
   libswscale      3.  1.101 /  3.  1.101
   libswresample   1.  1.100 /  1.  1.100
   libpostproc    53.  3.100 / 53.  3.100

 Source file excerpt (and resulting FFmpeg-processed dts excerpt) can be
 provided if needed.

--
Ticket URL: <https://trac.ffmpeg.org/ticket/4382>
FFmpeg <https://ffmpeg.org>
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