[FFmpeg-trac] #873(FFmpeg:new): PCM signed big-endian encoding as unsigned

[FFmpeg]

#873: PCM signed big-endian encoding as unsigned
-------------------------------------+-------------------------------------
             Reporter:  Glinx        |                    Owner:
                 Type:  defect       |                   Status:  new
             Priority:  normal       |                Component:  FFmpeg
              Version:  unspecified  |               Resolution:
             Keywords:  PCM signed   |               Blocked By:
  big endian                         |  Reproduced by developer:  0
             Blocking:               |
Analyzed by developer:  0            |
-------------------------------------+-------------------------------------

Comment (by cehoyos):

 Does the problem depend on -vcodec dnxhd or is it also reproducible with
 ffmpeg -i 00000.MTS -vn -sn -acodec pcm_s16be out.mov ?

 The version you are testing is ~800 changes behind git master, please
 either test a current snapshot or 0.9.1, see
 http://ffmpeg.org/download.html

 Why do you think your output is not signed 16bit? Please add the output of
 ffmpeg -i out.mov.
 {{{
 $ ffmpeg -i first-3_MiB-panasonic-busker-video.MTS -vn -sn -acodec
 pcm_s16be out.mov
 ffmpeg version N-36492-g7f83db3, Copyright (c) 2000-2012 the FFmpeg
 developers
   built on Jan  5 2012 06:49:27 with gcc 4.5.3
   configuration: --cc=/usr/local/gcc-4.5.3/bin/gcc
   libavutil      51. 34.100 / 51. 34.100
   libavcodec     53. 53.100 / 53. 53.100
   libavformat    53. 29.100 / 53. 29.100
   libavdevice    53.  4.100 / 53.  4.100
   libavfilter     2. 57.101 /  2. 57.101
   libswscale      2.  1.100 /  2.  1.100
   libswresample   0.  5.100 /  0.  5.100
 Input #0, mpegts, from 'first-3_MiB-panasonic-busker-video.MTS':
   Duration: 00:00:01.68, start: 0.888889, bitrate: 14979 kb/s
   Program 1
     Stream #0:0[0x1011]: Video: h264 (High) (HDMV / 0x564D4448), yuv420p,
 1280x720 [SAR 1:1 DAR 16:9], 25.62 fps, 25 tbr, 90k tbn, 100 tbc
     Stream #0:1[0x1100]: Audio: ac3 (AC-3 / 0x332D4341), 48000 Hz, stereo,
 s16, 192 kb/s
     Stream #0:2[0x1200]: Subtitle: hdmv_pgs_subtitle ([144][0][0][0] /
 0x0090)
 Output #0, mov, to 'out.mov':
   Metadata:
     encoder         : Lavf53.29.100
     Stream #0:0: Audio: pcm_s16be (twos / 0x736F7774), 48000 Hz, stereo,
 s16, 1536 kb/s
 Stream mapping:
   Stream #0:1 -> #0:0 (ac3 -> pcm_s16be)
 Press [q] to stop, [?] for help
 size=     319kB time=00:00:01.69 bitrate=1539.3kbits/s
 video:0kB audio:318kB global headers:0kB muxing overhead 0.214352%

 $ ffmpeg -i out.mov
 ffmpeg version N-36492-g7f83db3, Copyright (c) 2000-2012 the FFmpeg
 developers
   built on Jan  5 2012 06:49:27 with gcc 4.5.3
   configuration: --cc=/usr/local/gcc-4.5.3/bin/gcc
   libavutil      51. 34.100 / 51. 34.100
   libavcodec     53. 53.100 / 53. 53.100
   libavformat    53. 29.100 / 53. 29.100
   libavdevice    53.  4.100 / 53.  4.100
   libavfilter     2. 57.101 /  2. 57.101
   libswscale      2.  1.100 /  2.  1.100
   libswresample   0.  5.100 /  0.  5.100
 Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'out.mov':
   Metadata:
     major_brand     : qt
     minor_version   : 512
     compatible_brands: qt
     creation_time   : 1970-01-01 00:00:00
     encoder         : Lavf53.29.100
   Duration: 00:00:01.69, start: 0.000000, bitrate: 1539 kb/s
     Stream #0:0(eng): Audio: pcm_s16be (lpcm / 0x6D63706C), 48000 Hz, 2
 channels, s16, 1536 kb/s
     Metadata:
       creation_time   : 1970-01-01 00:00:00
       handler_name    :
                         DataHandler
 At least one output file must be specified
 }}}
 Note that FFmpeg reports the audio as 16bit signed big-endian, and both
 MPlayer and ffplay (and ffmpeg -i out.mov out.wav) correctly decode the
 sample. (None of them supports u16.)

-- 
Ticket URL: <https://ffmpeg.org/trac/ffmpeg/ticket/873#comment:3>
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