[FFmpeg-trac] #3332(undetermined:new): amovie+afade on MPEG-PS fades at wrong timestamp

FFmpeg trac at avcodec.org
Mon Jan 20 08:46:02 CET 2014


#3332: amovie+afade on MPEG-PS fades at wrong timestamp
-------------------------------------+-------------------------------------
             Reporter:  MarkZV       |                     Type:  defect
               Status:  new          |                 Priority:  normal
            Component:               |                  Version:  git-
  undetermined                       |  master
             Keywords:               |               Blocked By:
             Blocking:               |  Reproduced by developer:  0
Analyzed by developer:  0            |
-------------------------------------+-------------------------------------
 MPEG-PS audio that is read with `amovie` and faded out with `afade` fades
 out at the wrong timestamp.

 {{{
 # Create MPEG-PS containing 45 s of audio
 ffmpeg -f lavfi -i sine=b=4 -t 45 sine.mpg
 # fade out after 10 seconds
 ffplay -f lavfi amovie=sine.mpg,afade=t=out:st=10:d=1
 }}}

 This should fade out the audio after 10 seconds, but it actually fades out
 after about 2 seconds.  Similarly, with `st=30` it should fade out after
 30 seconds but it actually fades out after about 6 or 7 seconds.

 {{{
 $ ffmpeg -f lavfi -i sine=b=4 -t 45 sine.mpg
 ffmpeg version N-59995-g4014b40 Copyright (c) 2000-2014 the FFmpeg
 developers
   built on Jan 19 2014 22:18:54 with gcc 4.2.1 (GCC) (Apple Inc. build
 5666) (dot 3)
   configuration: --prefix=/opt/local --enable-swscale --enable-avfilter
 --enable-avresample --enable-libmp3lame --enable-libvorbis --enable-
 libopus --enable-libtheora --enable-libschroedinger --enable-libopenjpeg
 --enable-libmodplug --enable-libvpx --enable-libspeex --enable-libass
 --enable-libbluray --enable-gnutls --enable-fontconfig --enable-
 libfreetype --mandir=/opt/local/share/man --enable-pthreads
 --cc=/usr/bin/gcc-4.2 --arch=x86_64 --enable-yasm --enable-gpl --enable-
 postproc --enable-libx264 --enable-libxvid --enable-version3 --enable-
 libopencore-amrnb --enable-libopencore-amrwb --enable-nonfree --enable-
 libfdk-aac --enable-libfaac
   libavutil      52. 63.100 / 52. 63.100
   libavcodec     55. 48.101 / 55. 48.101
   libavformat    55. 25.100 / 55. 25.100
   libavdevice    55.  5.102 / 55.  5.102
   libavfilter     4.  1.100 /  4.  1.100
   libavresample   1.  1.  0 /  1.  1.  0
   libswscale      2.  5.101 /  2.  5.101
   libswresample   0. 17.104 /  0. 17.104
   libpostproc    52.  3.100 / 52.  3.100
 Input #0, lavfi, from 'sine=b=4':
   Duration: N/A, start: 0.000000, bitrate: 705 kb/s
     Stream #0:0: Audio: pcm_s16le, 44100 Hz, mono, s16, 705 kb/s
 Output #0, mpeg, to 'sine.mpg':
   Metadata:
     encoder         : Lavf55.25.100
     Stream #0:0: Audio: mp2, 44100 Hz, mono, s16, 128 kb/s
 Stream mapping:
   Stream #0:0 -> #0:0 (pcm_s16le -> mp2)
 Press [q] to stop, [?] for help
 size=     712kB time=00:00:44.99 bitrate= 129.6kbits/s
 video:0kB audio:703kB subtitle:0 global headers:0kB muxing overhead
 1.242114%
 $ ffplay -f lavfi amovie=sine.mpg,afade=t=out:st=10:d=1
 ffplay version N-59995-g4014b40 Copyright (c) 2003-2014 the FFmpeg
 developers
   built on Jan 19 2014 22:18:54 with gcc 4.2.1 (GCC) (Apple Inc. build
 5666) (dot 3)
   configuration: --prefix=/opt/local --enable-swscale --enable-avfilter
 --enable-avresample --enable-libmp3lame --enable-libvorbis --enable-
 libopus --enable-libtheora --enable-libschroedinger --enable-libopenjpeg
 --enable-libmodplug --enable-libvpx --enable-libspeex --enable-libass
 --enable-libbluray --enable-gnutls --enable-fontconfig --enable-
 libfreetype --mandir=/opt/local/share/man --enable-pthreads
 --cc=/usr/bin/gcc-4.2 --arch=x86_64 --enable-yasm --enable-gpl --enable-
 postproc --enable-libx264 --enable-libxvid --enable-version3 --enable-
 libopencore-amrnb --enable-libopencore-amrwb --enable-nonfree --enable-
 libfdk-aac --enable-libfaac
   libavutil      52. 63.100 / 52. 63.100
   libavcodec     55. 48.101 / 55. 48.101
   libavformat    55. 25.100 / 55. 25.100
   libavdevice    55.  5.102 / 55.  5.102
   libavfilter     4.  1.100 /  4.  1.100
   libavresample   1.  1.  0 /  1.  1.  0
   libswscale      2.  5.101 /  2.  5.101
   libswresample   0. 17.104 /  0. 17.104
   libpostproc    52.  3.100 / 52.  3.100
 Input #0, lavfi, from 'amovie=sine.mpg,afade=t=out:st=10:d=1':0/0
   Duration: N/A, start: 0.500000, bitrate: 705 kb/s
     Stream #0:0: Audio: pcm_s16le, 44100 Hz, mono, s16, 705 kb/s
    5.77 M-A:  0.000 fd=   0 aq=   11KB vq=    0KB sq=    0B f=0/0
 $
 }}}

--
Ticket URL: <https://trac.ffmpeg.org/ticket/3332>
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