[MPlayer-G2-dev] bypassing PTS in video filter layer

Michael Niedermayer michaelni at gmx.at
Sat Aug 2 22:41:22 CEST 2003


On Saturday 02 August 2003 19:28, Arpi wrote:
> - it's not completely true that I frames are keyframes in mpeg2. there are
>   streams (actually most of them i've seen) using partial update in I
> frames, ie. you need to decode 2 or more I frames to get the complete
> picture, otherwise you'll see checkboard-liek thing. just try to seek in
> some mpeg2 streams... (mostly true for DVD and DVB files). I frames don't
> use prediction (ie. reference frames), so you can seek to them, but also
> don't always cover the whole image area, so you can't simply skip them.
hmm, do u say that there are streams which have skiped MBs / skiped slices in 
I frames? the syntax would allow that but i thought thats not allowed in the 
standard or did u mean I field pictures, for these 2 are needed and the 
second could even be a P field picture ...

btw, mplayer should call AVCodec.flush() before seeking to avoid trashed B 
frames, as the "future" refrence frame is wrong immediately after seeking
I0 P2 B1 I4 B3
no seeking:	I0, I0->P2, I0->B1<-P2, I4, P2->B3<-I4
seeking:	I0, seek, I4, I0->B3<-I4


level[i]= get_vlc(); i+=get_vlc();		(violates patent EP0266049)
median(mv[y-1][x], mv[y][x-1], mv[y+1][x+1]);	(violates patent #5,905,535)
buf[i]= qp - buf[i-1];				(violates patent #?)
for more examples, see http://mplayerhq.hu/~michael/patent.html
stop it, see http://petition.eurolinux.org & http://petition.ffii.org/eubsa/en

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