[Ffmpeg-devel] directshow grab device?
Mon Apr 23 14:04:26 CEST 2007
On 4/23/07, Steve Lhomme <slhomme at corecodec.com> wrote:
> Aaron Griffin wrote:
> > Hey all,
> > I've looked through the archives, though not exhaustively, but I can't
> > seem to find a windows based grab device for libavformat besides
> > drffmpeg.
> > I'm curious if anyone has actually done work on this, and if the
> > ffmpeg people would be interested in this. The reason being that I am
> > currently writing a (commercial) app which does just this, and I was
> > debating doing the reverse of ffdshow - that is, convert directshow
> > style to ffmpeg, and not ffmpeg style to directshow.
> > Has anyone done any work in this regard and/or would be interested in
> > it if I were to throw something together?
> There is a version in the DrFFMPEG that compiled in both MSVC and MinGW.
> It was done a long time ago and not tested recently. So it may not work
> out of the box. The big issue is to pass the right parameters though
> (like capture devices and stuff like that). That was a GUI to help do
> that in Qt, but that GUI doesn't compile anymore...
> So with a little bit more work it could work.
True. The DrFFMPEG is the only implementation I've found of this, but
it does a couple of things I'm unsure of - one case of this is the
ISampleGrabber implementation vs the custom filter implementation. I
seriously have no idea which is better, but in all cases I've seen
(vlc, mplayer, drffmpeg, the mplayer tv patch) they are both used
identically. The only difference is that the ISampleGrabber
implementation requires somewhere in the realm of 75% less code, which
is usually a good thing as far as DirectShow is concerned.
In addition, and this is where I get fuzzy in the ffmpeg
implementation, it seems to me that audio and video capture should be
seperate. I do not know, however, how far along audio capture is in
ffmpeg, and haven't ever tried it actually. DrFFMPEG appears to do
both at the same time, which doesn't seem right to me.
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