On date Monday 2010-03-15 08:27:01 -0500, Bobby Bingham encoded: > On Mon, 15 Mar 2010 12:44:32 +0100 > Stefano Sabatini <[email protected]> wrote: > > > On date Sunday 2010-03-14 20:24:34 -0500, Bobby Bingham encoded: > > > On Sat, 13 Mar 2010 14:55:11 +0100 (CET) > > > stefano <[email protected]> wrote: > > > > > > > Author: stefano > > > > Date: Sat Mar 13 14:55:11 2010 > > > > New Revision: 5665 > > > > > > > > Log: > > > > Prevent rotate from calling avfilter_default_draw_slice(), which > > > > was causing randomic behaviour. > > > > > > > > Only one slice has to be passed to the next filter, in the > > > > end_frame() callback. > > > > > > Perhaps a better solution is actually to change > > > av_filter_draw_slice() to not call avfilter_default_draw_slice(). > > > I see three cases: > > > > > > 1. filters like vf_rotate, vf_transpose, etc which only send one > > > slice at the very end. These should not call > > > avfilter_default_draw_slice(). > > > > > > 2. filters which do some filtering in their own draw_slice. These > > > always override avfilter_default_draw_slice(). > > > > > > 3. filters which do not touch the video data: vf_null, vf_setpts, > > > etc. These can use avfilter_default_draw_slice(), but I think they > > > are the minority of filters. They can simply specify > > > avfilter_default_draw_slice as their draw_slice callback. > > > > I think the semantics for the default callbacks is this: > > "call the default callback if the callback is not explicitely defined > > in the filter". > > > > and should be respected for all the types of default_* callbacks. > > That is the way it's has been, but I originally did that with the goal > of making things easier for filter writers, rather than for > consistency. The default callbacks should be what filters are most > likely to use, and it looks like for draw_slice, a default > implementation which does nothing is more useful than > avfilter_default_draw_slice(). > > Another idea would be do provide an avfilter_null_draw_slice() so that > each filter doesn't have to provide its own.
I have no strong opinion but I like the avfilter_null_draw_slice() idea, as for changing the way avfilter_default_draw_slice() works, I'd say to wait to have more filters included, then we'll see how that will be convenient. [...] Regards. _______________________________________________ FFmpeg-soc mailing list [email protected] https://lists.mplayerhq.hu/mailman/listinfo/ffmpeg-soc
