Quoting Devin Heitmueller (2023-06-09 17:13:17) > Hi Artem, > > On Fri, Jun 9, 2023 at 9:19 AM Artem Smorodin > <artem.smoro...@telestream.net> wrote: > > > > When up-converting frame rate, ffmpeg duplicates frames including side > > data. This causes duplicated characters in the output. This patch removes > > A53 side data from duplicated frames. > > > > Signed-off-by: Artem Smorodin <artem.smoro...@telestream.net> > > --- > > fftools/ffmpeg_enc.c | 3 +++ > > 1 file changed, 3 insertions(+) > > > > diff --git a/fftools/ffmpeg_enc.c b/fftools/ffmpeg_enc.c > > index 2bf4782a9f..93d18034ca 100644 > > --- a/fftools/ffmpeg_enc.c > > +++ b/fftools/ffmpeg_enc.c > > @@ -1104,6 +1104,9 @@ static void do_video_out(OutputFile *of, OutputStream > > *ost, AVFrame *frame) > > else if (ret < 0) > > exit_program(1); > > > > + //Prevent duplicate Closed Captions at frame rate up-conversion > > + av_frame_remove_side_data(in_picture, AV_FRAME_DATA_A53_CC); > > + > > e->next_pts++; > > e->vsync_frame_number++; > > } > > -- > > 2.25.1 > > > > Disclaimer > > Unfortunately, the patch needed is more complicated than what you're > proposed. You can't simply drop the caption from the duplicated > frame, but rather the CC data needs to be rewritten in existing frames > with the appropriate cc_count and distribution of 608 pairs. > > I've reworked the logic to behave correctly if you use the "fps" video > filter, but had forgotten that using "-r" doesn't use that filter. > > Anton, is there any good reason we couldn't rework the "-r" command > line argument to invoke the fps filter (like we do with scaling) > rather than re-implementing the same functionality inside of the > ffmpeg program itself? It always seemed strange to me that it didn't > work that way from the beginning...
I don't think there's a fundamental reason -r handling could not be moved to lavfi, but it's a nontrivial task. E.g. the dup/drop counts are integrated with the CLI and would have to be exported from lavfi somehow if you wanted to keep that functionality. -- Anton Khirnov _______________________________________________ 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".
