[FFmpeg-trac] #1918(undetermined:open): Encoding errors with mp4 file

[FFmpeg]

#1918: Encoding errors with mp4 file
-------------------------------------+-------------------------------------
             Reporter:  fltmesoftly  |                    Owner:
                 Type:  defect       |                   Status:  open
             Priority:  normal       |                Component:
              Version:  git-master   |  undetermined
             Keywords:  aac mov      |               Resolution:
             Blocking:               |               Blocked By:
Analyzed by developer:  0            |  Reproduced by developer:  1
-------------------------------------+-------------------------------------
Changes (by cehoyos):

 * keywords:   => aac mov
 * status:  new => open
 * version:  1.0 => git-master
 * reproduced:  0 => 1


Comment:

 The sample triggers different problems afaict, at least some of them
 indicate bugs in the aac decoder, possibly related to ticket #1694.

 The first decoding problem occurs after 30 seconds, output changes to
 right-channel-ony, this cannot be undone with seeking, but if seeking is
 used to skip the position at ~30:00, output stays stereo. This is
 reproducible with both ffmpeg and ffplay (and MPlayer).
 {{{
 $ ffmpeg -ss 20 -i aark15sd_9A62E2FA.mp4 -t 20 out.wav
 ffmpeg version N-46747-ga1b5c96 Copyright (c) 2000-2012 the FFmpeg
 developers
   built on Nov 14 2012 13:20:14 with gcc 4.7 (SUSE Linux)
   configuration: --enable-libx264 --enable-libvo-aacenc --enable-libfdk-
 aac --enable-libfaac --disable-indev=jack --enable-gpl --enable-version3
 --enable-nonfree
   libavutil      52.  6.100 / 52.  6.100
   libavcodec     54. 71.100 / 54. 71.100
   libavformat    54. 36.100 / 54. 36.100
   libavdevice    54.  3.100 / 54.  3.100
   libavfilter     3. 23.100 /  3. 23.100
   libswscale      2.  1.102 /  2.  1.102
   libswresample   0. 16.100 /  0. 16.100
   libpostproc    52.  1.100 / 52.  1.100
 [mov,mp4,m4a,3gp,3g2,mj2 @ 0x2d01240] wrong sample count
 Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'aark15sd_9A62E2FA.mp4':
   Metadata:
     major_brand     : isom
     minor_version   : 1
     compatible_brands: isomavc1
     creation_time   : 2010-09-11 01:41:42
   Duration: 00:23:34.85, start: 0.021333, bitrate: 948 kb/s
     Stream #0:0(und): Video: h264 (Main) (avc1 / 0x31637661), yuv420p,
 640x480 [SAR 1:1 DAR 4:3], 800 kb/s, 23.97 fps, 23.97 tbr, 23970 tbn,
 47.94 tbc
     Metadata:
       creation_time   : 2010-09-11 01:41:42
       handler_name    : Imported with GPAC 0.4.6-DEV (internal rev. 5)
     Stream #0:1(und): Audio: aac (mp4a / 0x6134706D), 48000 Hz, stereo,
 s16
     Metadata:
       creation_time   : 2010-09-11 01:41:44
       handler_name    : GPAC ISO Audio Handler
 Output #0, wav, to 'out.wav':
   Metadata:
     major_brand     : isom
     minor_version   : 1
     compatible_brands: isomavc1
     ISFT            : Lavf54.36.100
     Stream #0:0(und): Audio: pcm_s16le ([1][0][0][0] / 0x0001), 48000 Hz,
 stereo, s16, 1536 kb/s
     Metadata:
       creation_time   : 2010-09-11 01:41:44
       handler_name    : GPAC ISO Audio Handler
 Stream mapping:
   Stream #0:1 -> #0:0 (aac -> pcm_s16le)
 Press [q] to stop, [?] for help
 [aac @ 0x2d09160] Input buffer exhausted before END element found
 Error while decoding stream #0:1: Operation not permitted
 [aac @ 0x2d09160] Reserved bit set.
 Error while decoding stream #0:1: Invalid data found when processing input
 [aac @ 0x2d09160] Reserved bit set.
 Error while decoding stream #0:1: Invalid data found when processing input
 [aac @ 0x2d09160] Reserved bit set.
 Error while decoding stream #0:1: Invalid data found when processing input
 size=    3768kB time=00:00:20.00 bitrate=1543.4kbits/s
 video:0kB audio:3768kB subtitle:0 global headers:0kB muxing overhead
 0.002073%
 }}}
 out.wav starts as a stereo file, switches to right-channel-only after ten
 seconds.
 The following command line produces a stereo file:
 {{{
 $ ffmpeg -ss 35 -i aark15sd_9A62E2FA.mp4 -t 20 out.wav
 }}}

 A not necessarily related problem is that when transcoding fails while
 writing a isom/mov file, the resulting file is unplayable because no moov
 atom is written on exit. This is not a regression afaik, and I don't know
 if / how this behaviour can be changed.
 {{{
 $ ffmpeg -ss 710 -i aark15sd_9A62E2FA.mp4 -vn -acodec mp2 out.mov
 }}}
 Audio decoding is impossible from ~12:00 on, encoding fails and out.mov is
 not a valid mov file.

-- 
Ticket URL: <https://ffmpeg.org/trac/ffmpeg/ticket/1918#comment:4>
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