Re: [FFmpeg-user] Slide show with vfr
Am 25.01.2021 um 23:45 schrieb Mark Filipak (ffmpeg): > regarding PTS variations, I've often found that simply remuxing an > existing stream via MKVToolNix has fixed the time stamps so that all > players play videos correctly. I tried that and can confirm that MKVToolNix does solve some issues with variable frame rate. At last, I ended up with Avidemux, which preserved vfr and provides some rudimentary filters, comprising a pts burn-in filter. Wolfgang Hugemann ___ ffmpeg-user mailing list ffmpeg-user@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-user To unsubscribe, visit link above, or email ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe".
Re: [FFmpeg-user] Slide show with vfr
On 01/25/2021 06:09 AM, Wolfgang Hugemann wrote: Express duration in seconds Repeat the last image as per https://trac.ffmpeg.org/wiki/Slideshow#Concatdemuxer Thanks for this hint. This really works and -vsync vfr seems to be necessary for mp4. (For mkv it works without that.) It works as well if you provide the durations in milliseconds, but there seems to be a problem with short durations, which are not reproduced exactly. So one should rather use durations larger than one second, as in the cited example. I now successfully produced a vfr mp4 with ffmpeg. Indeed, some applications as VLC do not handle the timestamps correctly, but AVidemux and ffplay do. Plus the vfr is preserved when the slide show is processed with ffmpeg (using -vsync vfr). Possibly, the relatively short durations in my original video are the reason for the problems with the original video, as there seem to be rounding errors. Wolfgang Hugemann I have not been following this thread as it doesn't interest me or apply to my use cases, however, regarding PTS variations, I've often found that simply remuxing an existing stream via MKVToolNix has fixed the time stamps so that all players play videos correctly. Bonus: The result is usually slightly smaller and MKVToolNix is very quick. I don't know what MKVToolNix is doing, but it's brilliant. -- Someone's sneaking in and turning up the range so that my food burns. I'm sure of it. And the older I get, the more sure of it I become. ___ ffmpeg-user mailing list ffmpeg-user@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-user To unsubscribe, visit link above, or email ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe".
Re: [FFmpeg-user] Slide show with vfr
Am Mo., 25. Jan. 2021 um 12:10 Uhr schrieb Wolfgang Hugemann : > I now successfully produced a vfr mp4 with ffmpeg. The author of the relevant code - Baptiste - claims that such files are not valid / do not conform to any specification. Carl Eugen ___ ffmpeg-user mailing list ffmpeg-user@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-user To unsubscribe, visit link above, or email ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe".
Re: [FFmpeg-user] Slide show with vfr
> Express duration in seconds > Repeat the last image as per > https://trac.ffmpeg.org/wiki/Slideshow#Concatdemuxer Thanks for this hint. This really works and -vsync vfr seems to be necessary for mp4. (For mkv it works without that.) It works as well if you provide the durations in milliseconds, but there seems to be a problem with short durations, which are not reproduced exactly. So one should rather use durations larger than one second, as in the cited example. I now successfully produced a vfr mp4 with ffmpeg. Indeed, some applications as VLC do not handle the timestamps correctly, but AVidemux and ffplay do. Plus the vfr is preserved when the slide show is processed with ffmpeg (using -vsync vfr). Possibly, the relatively short durations in my original video are the reason for the problems with the original video, as there seem to be rounding errors. Wolfgang Hugemann ___ ffmpeg-user mailing list ffmpeg-user@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-user To unsubscribe, visit link above, or email ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe".
Re: [FFmpeg-user] Slide show with vfr
Wolfgang Hugemann wrote > I did one step backward and tried to construct a vfr video from the > scratch using slides a an input: > > ffmpeg -y -f concat -i input.txt colors.mkv > > with input.txt as: > > ffconcat version 1.0 > file 'red.png' > duration 250ms > file 'yellow.png' > duration 500ms > file 'green.png' > duration 500ms > file 'cyan.png' > duration 250ms > file 'blue.png' > duration 500ms > file 'black.png' > duration 500ms > > This resulted in cfr for mp4 an vfr for mkv or webm (according to > MediaInfo, a Windows application). However, there seems to be something > wrong with the result colors.mkv, as no player, including ffplay uses > the specified durations. Express duration in seconds Repeat the last image as per https://trac.ffmpeg.org/wiki/Slideshow#Concatdemuxer file 'red.png' duration 0.25 file 'yellow.png' duration 0.5 file 'green.png' duration 0.5 file 'cyan.png' duration 0.25 file 'blue.png' duration 0.5 file 'black.png' duration 0.5 file 'black.png' -- Sent from: http://ffmpeg-users.933282.n4.nabble.com/ ___ ffmpeg-user mailing list ffmpeg-user@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-user To unsubscribe, visit link above, or email ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe".
Re: [FFmpeg-user] Slide show with vfr
Am So., 24. Jan. 2021 um 18:23 Uhr schrieb Wolfgang Hugemann : > > I did one step backward and tried to construct a vfr video from the > scratch using slides a an input: > > ffmpeg -y -f concat -i input.txt colors.mkv > > with input.txt as: > > ffconcat version 1.0 > file 'red.png' > duration 250ms > file 'yellow.png' > duration 500ms > file 'green.png' > duration 500ms > file 'cyan.png' > duration 250ms > file 'blue.png' > duration 500ms > file 'black.png' > duration 500ms > > This resulted in cfr for mp4 an vfr for mkv or webm (according to > MediaInfo, a Windows application). However, there seems to be something > wrong with the result colors.mkv, as no player, including ffplay uses > the specified durations. I suspect that no player is able to deal with above frame durations. Old RealMedia files can be good sources for vfr tests. Carl Eugen ___ ffmpeg-user mailing list ffmpeg-user@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-user To unsubscribe, visit link above, or email ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe".
