[Ffmpeg-devel] [PATCH] AVISynth support

Steve Lhomme slhomme
Thu Aug 17 16:58:45 CEST 2006

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.


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