> -----Original Message----- > From: ffmpeg-devel <ffmpeg-devel-boun...@ffmpeg.org> On Behalf Of Tobias > Rapp > Sent: joi, 13 iunie 2024 16:18 > To: ffmpeg-devel@ffmpeg.org > Subject: Re: [FFmpeg-devel] [PATCH v3] area changed: scdet filter > > On 13/06/2024 13:21, radu.taraib...@gmail.com wrote: > > >> -----Original Message----- > >> From: ffmpeg-devel<ffmpeg-devel-boun...@ffmpeg.org> On Behalf Of > >> Tobias Rapp > >> Sent: joi, 13 iunie 2024 12:52 > >> To:ffmpeg-devel@ffmpeg.org > >> Subject: Re: [FFmpeg-devel] [PATCH v3] area changed: scdet filter > >> > >> On 12/06/2024 21:51,radu.taraib...@gmail.com wrote: > >> > >> [...] > >> > >>> diff --git a/doc/filters.texi b/doc/filters.texi index > >>> bfa8ccec8b..53814e003b 100644 > >>> --- a/doc/filters.texi > >>> +++ b/doc/filters.texi > >>> @@ -21797,6 +21797,22 @@ Default value is @code{10.}. > >>> @item sc_pass, s > >>> Set the flag to pass scene change frames to the next filter. > >>> Default value is @code{0} > >>> You can enable it if you want to get snapshot of scene change > >>> frames only. > >>> + > >>> +@item mode > >>> +Set the scene change detection method. Default value is @code{-1} > >>> +Available values are: > >>> + > >>> +@table @samp > >>> +@item -1 > >>> +Legacy mode for sum of absolute linear differences. Compare frame > >>> with previous only and no delay. > >>> + > >>> +@item 0 > >>> +Sum of absolute linear differences. Compare frame with both > >>> +previous > >>> and next which introduces a 1 frame delay. > >>> + > >>> +@item 1 > >>> +Sum of mean of cubic root differences. Compare frame with both > >>> previous and next which introduces a 1 frame delay. > >>> + > >>> +@end table > >>> @end table > >>> > >>> @anchor{selectivecolor} > >> Out of curiosity: How do these three modes roughly compare (CPU) > >> performance wise? > > Mode -1 is virtually equal with mode 0 (no frame clone speedup of mode 0 is > mostly theoretical). Mode 1 is roughly 40% slower, depending on input, it > could benefit from ASM. > > > >> I'd prefer if mode "-1" could be used for the default case, and the > >> three modes get explicit values 0/1/2. > > So you want four possible values for mode where the default -1 is the same as > one of the others? > > Yes. This pattern is also used for the "shaping" option of the ass filter, for > example.It allows users to make it explicit that the filter should choose a > default (which may vary between versions).
Scdet filter doesn't choose a mode. The default has to be current "Legacy" for backward compatibility. I will renumber modes to 0/1/2 to avoid confusion with an "auto" (-1) option. > >> Regarding naming I think that the "Legacy" mode still has its > >> usecases in the future. Naming it something like "simple" would not > >> imply that it is deprecated in general, but rather that it has lower > >> precision (and is possibly faster). > >> > > OK, I will rename "Legacy" mode so it doesn't look deprecated to somebody > that can't allow 1 frame delay. Otherwise it shouldn't be used. > > Thanks. > > Regards, Tobias > _______________________________________________ > ffmpeg-devel mailing list > ffmpeg-devel@ffmpeg.org > https://ffmpeg.org/mailman/listinfo/ffmpeg-devel > > To unsubscribe, visit link above, or email ffmpeg-devel-requ...@ffmpeg.org > with subject "unsubscribe". _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-devel To unsubscribe, visit link above, or email ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe".