[Ffmpeg-devel] [Bad news]: MPEG Seek has failed to work in FFmpeg SVN

[Steve Lhomme]

M?ns Rullg?rd wrote:
> Steve Lhomme said:
>> QuickTime wrote:
>>> Dear:
>> Hi Quicktime,
>>
>>> FFmpeg fails to decode video(avcodec_decode_video() never return
>>> picture) after perform SEEK on mpeg file format
>>>
>>> It seems that the seek&decode abiliity for mpeg files have been broken
>>> for 2 months(ealier than August )
>>>
>>> ffmpeg  -ss 00:00:10 -i test.mpg  -r 25 test.mp4
>>> .....
>>> Input #0, mpeg, from 'test.mpg':
>>>  Duration: 00:00:24.0, start: 0.346711, bitrate: 2314 kb/s
>>>  Stream #0.0[0x1e0]: Video: mpeg1video, yuv420p, 352x288, 2000 kb/s,
>>> 25.00 fps(r)
>>>  Stream #0.1[0x1c0]: Audio: mp2, 44100 Hz, stereo, 192 kb/s
>>> Output #0, mp4, to 'test.mp4':
>>>  Stream #0.0: Video: mpeg4, yuv420p, 352x288, q=2-31, 200 kb/s, 25.00
>>> fps(c)
>>>  Stream #0.1: Audio: aac, 44100 Hz, stereo, 64 kb/s
>>> Stream mapping:
>>>  Stream #0.0 -> #0.0
>>>  Stream #0.1 -> #0.1
>>> frame=    0 q=0.0 Lsize=     120kB time=14.8 bitrate=  66.1kbits/s
>>> video:0kB audio:114kB global headers:0kB muxing overhead 4.833664%
>>> .....
>> I've had similar problems (actually crashes) with some MPEG2 samples
>> (from DVDs) for a long time. Maybe if you can provide a sample and say
>> what platform you use, it could help.
> 
> Yeah, if Steve hadn't refused to provide samples, maybe this had been fixed
> already.

Look at the message "Re: [Ffmpeg-devel] MPEG2 decoding problems" from 
2006-03-02 there is a chems1.vob sample. The URL should still work.

It was not fixed because you need to seek at a specific place in the 
file to crash. Maybe you can manage to do that by doing a 
forward/backward seek in ffplay during a specific fraction of second 
during playback. I proposed to modify ffplay to test it but it was 
rejected...

Steve