On Sun, Dec 27, 2020 at 7:53 PM Mark Filipak (ffmpeg) <[email protected]> wrote:
> On 12/27/2020 01:23 PM, Paul B Mahol wrote: > > On Sun, Dec 27, 2020 at 6:45 PM Mark Filipak (ffmpeg) < > [email protected]> > > wrote: > > > >> On 12/27/2020 06:19 AM, Paul B Mahol wrote: > >>> On Sun, Dec 27, 2020 at 5:00 AM Mark Filipak (ffmpeg) < > >> [email protected]> > >>> wrote: > >>> > >>>> Decimation with ppsrc=1 malfunctions. > >> > >>>> Paul fixed this somewhat, but it's still in trouble. > >>>> Since I eliminated threading and decimation as the cause, I suspect > that > >>>> frames numbers are being > >>>> bollixed. > >>>> > >>>> The report package is here: > >>>> https://www.dropbox.com/t/zu4cezneCJIsdmUu > >> > >>> decimate filter only drops frames, it never fixes combing. > >> > >> Of course. > >> > >>> Do you know exact telecine pattern used in your samples? > >> > >> Look at 'source.mkv frames 1018-1029.png'. I have a scenario that > explains > >> why a sober engineer > >> would be forced to do what was done, but what's the point? Combing is > not > >> the issue. The issue is > >> that the duplicate (modulo 5) frames found in preprocessed.mkv are not > >> being removed from source.mkv. > >> > >> source.mkv & preprocessed.mkv are 172 frames. target.mkv should be 138 > >> frames. It is 138 frames, but > >> they are the wrong frames. Worse, the frames removed are not modulo 5 > but > >> vary instead. The only > >> cause I could imagine was a mixup due to a threading mixup but > >> single-threading didn't solve the > >> problem. > > > > I really wonder what is your real motivation to write so long text > > basically saying nothing. > > My motivation (as always) is to get the best possible transcode given the > existing source video. > > > Decimate filter removes duplicated decombed frames from field match > > processing. > > Combed or decombed, what does that matter? What matters is duplicated > frames. > > > Using it for anything other is pointless. > > > > For default cycle of 5 it removes single frame from every 5 frames than > > have the lowest threshold. > > In preprocessed.mkv every 5th frame is a repeat of frame 4. This is > confirmed because decimating > prepreocessed.mkv succeeds. However, applying decimate=ppsrc=1 does not > remove the correct frames > from source.mkv. How can that happen? > > > If you wish to drop every fixed X-th frame from every cycle frames of 5 > use > > shuffleframes or select filter. > > I can't (easily) predict in advance which frame is the repeat. Simply > removing it via decimate > solves the first step of the problem no matter which frame is the repeated > frame. > > Decimate would work with source.mkv if source.mkv didn't have frame > numbers burned in. But > source.mkv does have frame numbers burned in. My approach is to cut out > the burned-in frame numbers > from source.mkv and save the target as 'preprocessed.mkv', then use > preprocessed.mkv as the template > (via decimate=ppsrc=1) to drop the correct frames from source.mkv. Bbut > that didn't work. It appears > that between preprocessed.mkv and the decimation of source.mkv, the frame > numbers are getting mixed up. > > Now, I know that the problem isn't with preprocessed.mkv. I know that > because if I decimate > preprocessed.mkv, the correct frames are dropped. So the problem must be > the communication between > decimate=ppsrc=1 and the handler that's dropping frames from source.mkv. > I dunno what is your issue with decimate filter, but I just fixed behavior with ppsrc=1 handling when output would not match VIVTC from VDecimate filter. Previously wrong frames would be dropped, the spots for dropped frames are still at correct place and works as intended. > _______________________________________________ > ffmpeg-user mailing list > [email protected] > https://ffmpeg.org/mailman/listinfo/ffmpeg-user > > To unsubscribe, visit link above, or email > [email protected] with subject "unsubscribe". _______________________________________________ ffmpeg-user mailing list [email protected] https://ffmpeg.org/mailman/listinfo/ffmpeg-user To unsubscribe, visit link above, or email [email protected] with subject "unsubscribe".
