[FFmpeg-trac] #3182(undetermined:open): A/V desync when transcoding MPEG-TS streams if an audio track disappears

[FFmpeg]

#3182: A/V desync when transcoding MPEG-TS streams if an audio track disappears
-------------------------------------+-------------------------------------
             Reporter:  aurelien     |                    Owner:
                 Type:  defect       |                   Status:  open
             Priority:  normal       |                Component:
              Version:  git-master   |  undetermined
             Keywords:  mpegts       |               Resolution:
             Blocking:               |               Blocked By:
Analyzed by developer:  0            |  Reproduced by developer:  1
-------------------------------------+-------------------------------------
Changes (by cehoyos):

 * status:  new => open
 * component:  avformat => undetermined
 * reproduced:  0 => 1


Comment:

 Thank your for the sample!
 For future tickets: Please do not use external libraries like libx264 and
 libfdk-aac if they are not needed to reproduce the problem.

 The following produces an output file that plays severely out-of-sync,
 {{{-async 1}}} does not help, I don't think this is a regression:
 {{{
 $ ffmpeg -i ntd_gap_sound.ts -qscale 10 out.ts
 ffmpeg version N-58656-gbd9de4f Copyright (c) 2000-2013 the FFmpeg
 developers
   built on Nov 30 2013 11:55:29 with gcc 4.7 (SUSE Linux)
   configuration: --enable-gpl
   libavutil      52. 55.100 / 52. 55.100
   libavcodec     55. 44.100 / 55. 44.100
   libavformat    55. 21.102 / 55. 21.102
   libavdevice    55.  5.102 / 55.  5.102
   libavfilter     3. 91.100 /  3. 91.100
   libswscale      2.  5.101 /  2.  5.101
   libswresample   0. 17.104 /  0. 17.104
   libpostproc    52.  3.100 / 52.  3.100
 [mpeg2video @ 0x2e0b780] Invalid frame dimensions 0x0.
     Last message repeated 19 times
 Input #0, mpegts, from 'ntd_gap_sound.ts':
   Duration: 00:01:08.87, start: 50432.154678, bitrate: 3972 kb/s
   Program 1701
     Metadata:
       service_name    : MTV Portugal
       service_provider: Arqiva
   Program 1715
     Metadata:
       service_name    : D1 DAB
       service_provider: Arqiva
   Program 1720
     Metadata:
       service_name    : ANN
       service_provider: Arqiva
   Program 1740
     Metadata:
       service_name    : DCRO
       service_provider: Arqiva
   Program 1741
     Metadata:
       service_name    : DCBU
       service_provider: Arqiva
   Program 1752
     Metadata:
       service_name    : NTDTV
       service_provider: Arqiva
     Stream #0:0[0xa47]: Video: mpeg2video (Main) ([2][0][0][0] / 0x0002),
 yuv420p(tv), 544x576 [SAR 24:17 DAR 4:3], max. 15000 kb/s, 25 fps, 25 tbr,
 90k tbn, 50 tbc
     Stream #0:1[0xa48](eng): Audio: mp2 ([4][0][0][0] / 0x0004), 48000 Hz,
 stereo, s16p, 128 kb/s
   Program 1760
     Metadata:
       service_name    : Il Sole
       service_provider: Arqiva
   Program 1765
     Metadata:
       service_name    : Deepam TV
       service_provider: Arqiva
   Program 1775
     Metadata:
       service_name    : GTV
       service_provider: Arqiva
   Program 1780
     Metadata:
       service_name    : Fox Sports HD
       service_provider: Arqiva
 Please use -q:a or -q:v, -qscale is ambiguous
 Output #0, mpegts, to 'out.ts':
   Metadata:
     encoder         : Lavf55.21.102
     Stream #0:0: Video: mpeg2video, yuv420p, 544x576 [SAR 24:17 DAR 4:3],
 q=2-31, 200 kb/s, 90k tbn, 25 tbc
     Stream #0:1(eng): Audio: mp2, 48000 Hz, stereo, s16, 128 kb/s
 Stream mapping:
   Stream #0:0 -> #0:0 (mpeg2video -> mpeg2video)
   Stream #0:1 -> #0:1 (mp2 -> mp2)
 Press [q] to stop, [?] for help
 frame=  416 fps=0.0 q=10.0 size=    3267kB time=00:00:16.56
 bitrate=1616.3kbits/s dup=31 drop=0   [mpegts @ 0x2de7900] PES packet size
 mismatch
 [mp2 @ 0x2e0d100] Header missing
 Error while decoding stream #0:1: Invalid data found when processing input
 frame= 1218 fps=1217 q=10.0 size=    3498kB time=00:00:48.64 bitrate=
 589.1kbits/s dup=31 drop=0  [mpegts @ 0x2de7900] PES packet size mismatch
 [mp2 @ 0x2e0d100] Header missing
 Error while decoding stream #0:1: Invalid data found when processing input
 [mpeg2video @ 0x2e0b780] ac-tex damaged at 25 34
 [mpeg2video @ 0x2e0b780] Warning MVs not available
 [mpeg2video @ 0x2e0b780] concealing 68 DC, 68 AC, 68 MV errors in P frame
 frame= 1723 fps=1169 q=10.0 Lsize=    5619kB time=00:01:08.88 bitrate=
 668.2kbits/s dup=33 drop=0
 video:4434kB audio:592kB subtitle:0 global headers:0kB muxing overhead
 11.780382%
 }}}
 The following commands work as expected:
 {{{
 $ ffmpeg -ss 30 -i ntd_gap_sound.ts -qscale 10 out.ts
 }}}
 {{{
 $ ffmpeg -skip_initial_bytes 25000000 -i ntd_gap_sound.ts -qscale 10
 out.ts
 }}}

--
Ticket URL: <https://trac.ffmpeg.org/ticket/3182#comment:3>
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