On date Tuesday 2010-03-30 17:15:04 -0400, Brandon Mintern encoded: > On Sat, Mar 27, 2010 at 9:27 AM, Stefano Sabatini > <[email protected]> wrote: > > On date Saturday 2010-03-27 07:46:26 -0400, Brandon Mintern encoded: > >> I'm trying to build a filter called "clone" (as discussed with Vitor > >> on #ffmpeg-devel). I was modeling my filter after fifo, but apparently > >> I'm wrong about the callback process (sidenote: a more detailed > >> explanation in the wiki documentation would be very helpful!). I think > >> I'm reasonably close with the code I have, but I can't finish it until > >> I better understand the callback order in the filter chain. I would > >> appreciate it if someone could point me in the write direction. > > > > Quick reply as I don't have much time at this moment: enable the DEBUG > > symbol in avfilter.c and use -logleve debug, that should show you when > > every callback is called and understand how the filterchain processing > > stuff works. > > Thank you for this tip. I made a lot of changes after checking out > vf_fps.c, tried your DEBUG tip, and the first function I see being > called is request_frame. This seemed incorrect (shouldn't at least > init() be called first?), so I added av_log(..., AV_LOG_DEBUG, ...) > messages to the beginning and end of all my functions. It turns out > that for some reason, init really isn't being called, which helps > explain the current Segmentation fault that I'm running into. > > I think that for now I'll move onto something easier (vf_fade.c), but > if someone wouldn't mind taking a look at what I've done I would > really appreciate it. I really can't figure out what's wrong now. The > following patch: > > http://bmintern.homeunix.com/~brandon/vf_clone.patch
I can assure you that init is called. At this point I recommend you to use gdb, that will make things *lots* easier. (I'll have a deeper look at the patch tomorrow evening or later.) > is the result of running "svn diff" against the latest libavfilter > (revision 5726). I guess if I don't hear anything soon, I'll write a > simpler "vf_frame.c" which will simply output a single given frame a > specified number of times (rather than a sequence of frames) and see > if maybe I can get that working. > > > And thanks for the contribution. BTW if you're a student and > > interested we have a libavfilter GSoC task just waiting for you, or > > for any interested student. > > Unfortunately I'm no longer a student. Otherwise I would be *very* interested. Too bad. Regards. _______________________________________________ FFmpeg-soc mailing list [email protected] https://lists.mplayerhq.hu/mailman/listinfo/ffmpeg-soc
