[Ffmpeg-devel] [PATCH] AVISynth support

Michael Niedermayer michaelni
Thu Aug 17 22:18:00 CEST 2006


On Thu, Aug 17, 2006 at 04:58:45PM +0200, Steve Lhomme wrote:
> Reimar D?ffinger wrote:
> >Hello,
> >On Thu, Aug 17, 2006 at 04:31:16PM +0200, Steve Lhomme wrote:
> >>I'm actually adding a small header in the raw virtual stream so that I 
> >>can add a probe to the demuxer. It's not that hard. But adding RIFF 
> >>headers is a lot more work. Especially since the virtual file is usually 
> >>much bigger than 4GB. I know it should be OpenDML but I don't know how 
> >>it's interleaved.
> >
> >If you don't support seeking IIRC there is no point in using OpenDML, if
> >you want to support that I think that will be problematic anyway and
> >probably not possible while keeping the stream/demuxer split, since you
> >must give AVISynth the frame number you want but stream layer works with
> >byte position. Or am I missing something?
> Actually doing the header in the virtual stream is easy. But when I read 
> the packets I need to set the position at the right packet boundaries so 
> I have to access the virtual stream even more to do so... So I won't add 
> it in the end. It's an extra hack for no real life use.
> Yes, seeking is not only needed in the virtual stream (also called 
> protocol) but I don't think it would work otherwise with av_stream_info 
> and stuff like that. At first I just made a demuxer and no virtual 
> stream. It was working fine but url_ftell() was always wrong and that's 
> what we use in DrDivX to track progress in the encoding/analysis so I 
> added the virtual stream.

hmm, implementing avisynth support purely in the demxuer without any
stream/protocol also sounds acceptable, do you still have that code?
the url_ftell() issue can maybe be solved by using AVPacket.pos or
using AVPacket.dts and AVstream.duration instead

Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

In the past you could go to a library and read, borrow or copy any book
Today you'd get arrested for mere telling someone where the library is

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