[FFmpeg-devel] [PATCH] Reduce exessive seeking in mov demuxer

Michael Niedermayer michaelni
Sat Oct 6 01:40:51 CEST 2007


On Fri, Oct 05, 2007 at 10:47:55PM +0200, Baptiste Coudurier wrote:
> Hi Michael,
> Michael Niedermayer wrote:
> > Hi
> > 
> > On Fri, Oct 05, 2007 at 09:46:28PM +0200, elupus wrote:
> > 
> >>Hi,
> >>
> >>This patch reduces the exessive seeking back and forth using the mov 
> >>demuxer. Current code selects the next packet to read based on lowest dts 
> >>of all possible streams. For some reason alot of mov files are muxed in 
> >>such a way that that isn't always the order in wich they come in the 
> >>stream. This patch changes the selection to be based on the position in the 
> >>stream instead.
> >>
> >>Now if you know the filesystem has fast seeking, this might not be the best 
> >>way. But I think it is better to have as default.
> > 
> > 
> > the (obvious?) problem is that your patch will totally break files which
> > arent approximately correctly interleaved
> > (yeah 2 hours of video before the first audio packet doesnt work, or to say
> > it differently you will run out of memory to buffer a few gb of video)
> > still a mov file doing that is perfectly valid ...
> > 
> Yes, I totally agree.
> Im still thinking about a nice way to handle piped or streamed files
> where it might be better to read by position.
> Demuxing that way for url_is_streamed files might be ok.
> What do you think about that ?

i think its a good idea

Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

Good people do not need laws to tell them to act responsibly, while bad
people will find a way around the laws. -- Plato
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