[FFmpeg-user] Mjpeg to h264 audio sync problem

[Christian Ebert]

* Petr Tresnak on Friday, December 05, 2014 at 10:34:50 +0000
> the sound start is cut and audio is ahead even more with your command line.
> 
> ffmpeg -i mjpeg.avi -qscale 2 -strict -2 -vcodec mpeg4 -acodec aac out.mp4
> 
> encoder         : Lavf56.14.100
> Duration: 00:00:14.39, start: 0.092880, bitrate: 873 kb/s
> Stream #0:0(und): Video: mpeg4 (Simple Profile) (mp4v / 0x7634706D), yuv420p, 640x480 [SAR 1:1 DAR 4:3], 818 kb/s, 30 fps, 30 tbr, 65521 tbn, 65521 tbc (default)
> Stream #0:1(und): Audio: aac (LC) (mp4a / 0x6134706D), 11025 Hz, mono, fltp, 57 kb/s (default)
> 
> Here you have full console output:
> 
> ffmpeg version git-2014-11-20-e39f8fa Copyright (c) 2000-2014 the FFmpeg developers
>  built on Nov 20 2014 12:58:03 with gcc 4.9.2 (Rev2, Built by MSYS2 project)
>  configuration: --arch=x86 --disable-debug --disable-shared --disable-doc --enable-gpl --enable-version3 --enable-runtime-cpudetect --enable-avfilter --enable-
> bzlib --enable-zlib --enable-librtmp --enable-gnutls --enable-avisynth --enable-frei0r --enable-filter=frei0r --enable-libbluray --enable-libcaca --enable-libop
> enjpeg --enable-fontconfig --enable-libfreetype --enable-libass --enable-libgsm --enable-libilbc --enable-libmodplug --enable-libmp3lame --enable-libopencore-am
> rnb --enable-libopencore-amrwb --enable-libvo-amrwbenc --enable-libschroedinger --enable-libsoxr --enable-libtwolame --enable-libspeex --enable-libtheora --enab
> le-libutvideo --enable-libvorbis --enable-libvo-aacenc --enable-openal --enable-libopus --enable-libvidstab --enable-libvpx --enable-libwavpack --enable-libxavs
> --enable-libx264 --enable-libx265 --enable-libxvid --enable-libzvbi --enable-nonfree --enable-libfaac --enable-libfdk-aac
>  libavutil      54. 14.100 / 54. 14.100
>  libavcodec     56. 12.101 / 56. 12.101
>  libavformat    56. 14.100 / 56. 14.100
>  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
> Guessed Channel Layout for  Input Stream #0.1 : mono
> Input #0, avi, from 'input.avi':
>  Metadata:
>    creation_time   : 2005-12-30 14:13:20
>    encoder         : CanonMVI02
>  Duration: 00:00:14.30, start: 0.000000, bitrate: 14883 kb/s
>    Stream #0:0: Video: mjpeg (MJPG / 0x47504A4D), yuvj422p(pc, bt470bg/unknown/unknown), 640x480, 14823 kb/s, 30 fps, 30 tbr, 30 tbn, 30 tbc
>    Stream #0:1: Audio: pcm_u8 ([1][0][0][0] / 0x0001), 11024 Hz, 1 channels, u8, 88 kb/s
> [swscaler @ 051d8080] deprecated pixel format used, make sure you did set range correctly
> Output #0, mp4, to 'output.mp4':
>  Metadata:
>    encoder         : Lavf56.14.100
>    Stream #0:0: Video: mpeg4 ( [0][0][0] / 0x0020), yuv420p, 640x480, q=2-31, 200 kb/s, 30 fps, 65521 tbn, 30 tbc
>    Metadata:
>      encoder         : Lavc56.12.101 mpeg4
>    Stream #0:1: Audio: aac ([64][0][0][0] / 0x0040), 11025 Hz, mono, fltp, 64 kb/s
>    Metadata:
>      encoder         : Lavc56.12.101 aac
> Stream mapping:
>  Stream #0:0 -> #0:0 (mjpeg (native) -> mpeg4 (native))
>  Stream #0:1 -> #0:1 (pcm_u8 (native) -> aac (native))
> Press [q] to stop, [?] for help
> frame=  429 fps=266 q=31.0 Lsize=    1535kB time=00:00:14.30 bitrate= 879.0kbits/s
> video:1428kB audio:101kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 0.374799%
> Press any key to continue . . .

Seems related to
https://trac.ffmpeg.org/ticket/3859

aac duration is rarely the same as the video, in your case it
looks like the audio is truncated.

-- 
Auftreten Tarzan und Martha -
ich hatte Sankt Pauli unterschätzt.

_MICHAEL WEBER: MARTHA_ --->> http://www.blacktrash.org/baustellen/#martha