[FFmpeg-devel] MainConcept mpeg not decoding properly.

Media Streaming Services mediastream
Sat Jan 12 19:04:30 CET 2008


> > > On Fri, Jan 11, 2008 at 12:03:05PM -0500, Media Streaming Services wrote:
> > >> Hi all.
> > >>
> > >> I'm trying to encode mpg to 3gp and have problems with the source file.
> > >> Audio track is encoded as 140 seconds and video is 206 seconds...
> > >>
> > >> http://rapidshare.com/files/82302675/DA_117588fd522.mpg.html
> > >> I've tried uploading to mplayer's ftp, but the file gets deleted soon
> > >> after I finish uploading.
> > >>
> > >> it's a MainConcept muxed mpeg2-ps. Plays fin in Windows graphedit&WMP using
> > >> Mainconcept demuxer.
> > >>
> > >> I have tried -vcodec h264, -acodec liba52, -f mpeg, -f svd, -f dvd,
> > >> -async 1, -vsync 1... all produce bad files, asynch had actually
> > >> produced file with equal video and audio length, but audio got
> > >> "chopped up". Is it a bug? Or am I doing something wrong?
> > >>
> > >> /usr/local/bin/ffmpeg -f dvd -vcodec h264 -i DA_117588fd522.mpg
> > >> -bitexact 1 -vcodec mpeg4 -deinterlace -s 176x144 -r 12 -b 92k -nr 1
> > >> -preme 1 -bt 100k  -lowres 1 -trell 1 -maxrate 110k -bufsize 256k -vol
> > >> 400  -acodec libamr_nb -ac 1 -ar 8000 -ab 12.2k -y -pass 2 9.3gp
> > >
> > > please provide a minimum command line to reproduce it and full uncut
> > > output of ffmpeg
> >
> > Here's what I used:
> >
> > $ ffmpeg -i DA_117588fd522.mpg -an -f image2 foo/%03d.png
> > FFmpeg version git-55839b7, Copyright (c) 2000-2008 Fabrice Bellard, et al.
> >   configuration: --cc=gcc-4.2.2 --cpu=nocona --enable-gpl
> >   libavutil version: 49.6.0
> >   libavcodec version: 51.49.0
> >   libavformat version: 52.3.0
> >   libavdevice version: 52.0.0
> >   built on Jan 11 2008 21:38:35, gcc: 4.2.2 (Gentoo 4.2.2 p1.0)
> > Input #0, mpeg, from 'DA_117588fd522.mpg':
> >   Duration: 00:02:20.8, start: 1.830000, bitrate: 1702 kb/s
> >     Stream #0.0[0x1e0]: Video: h264, yuv420p, 320x240 [PAR 1:1 DAR 4:3], 25.00 tb(r)
> >     Stream #0.1[0x1c0]: Audio: mp2, 44100 Hz, stereo, 192 kb/s
> > Output #0, image2, to 'foo/%03d.png':
> >     Stream #0.0: Video: png, rgb24, 320x240 [PAR 1:1 DAR 4:3], q=2-31, 200 kb/s, 25.00 tb(c)
> > Stream mapping:
> >   Stream #0.0 -> #0.0
> > Press [q] to stop encoding
> > frame=  994 fps= 74 q=0.0 Lsize=      -0kB time=39.8 bitrate=  -0.0kbits/s
> > video:18797kB audio:0kB global headers:0kB muxing overhead -100.000114%
> >
> > FWIW, the file plays fine with tcvp using its demuxer and lavc
> > decoder.
> >
>
> Oh yes, it decodes video and audio track fine, just not reading them
> at the same duration.
> The clip is 2:20 but video is generated as 3:28.666 sec track (666...
> it has to be it :)
>
>
> * Movie Info *
>         Timescale 1000 - Duration 00:03:28.667
>         Fragmented File no - 2 track(s)
>         File Brand 3gp4 - version 512
>         Created: GMT Fri Jan  2 00:00:00 1970
>
> File has no MPEG4 IOD/OD
>
> Track # 1 Info - TrackID 1 - TimeScale 12 - Duration 00:03:28.666
> Media Info: Language "Undetermined" - Type "vide:mp4v" - 2504 samples
> MPEG-4 Config: Visual Stream - ObjectTypeIndication 0x20
> MPEG-4 Visual Size 176 x 144 - Simple Profile @ Level 1
> Pixel Aspect Ratio 12:11 - Indicated track size 192 x 144
> Self-synchronized
>
> Track # 2 Info - TrackID 2 - TimeScale 8000 - Duration 00:02:20.840
> Media Info: Language "Undetermined" - Type "soun:samr" - 7042 samples
>         3GPP AMR stream - Sample Rate 8000 - 2 channel(s) 16 bits per samples


If I generate AVI, MPEG, 3GP or MP4 files from the same source they
all have video track at 3:28 instead of 2:20. I have a number of
similar MainConcept mpg files (H264 + MP2) and all produce same
results - video track is much longer than audio track.
Is it  a bug?

thanks.




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