пн, 8 янв. 2024 г., 09:13 Mark Filipak <markfilipak.i...@gmail.com>:
> On 1/8/24 00:26, Andrew Randrianasulu wrote: > > пн, 8 янв. 2024 г., 05:14 Mark Filipak <markfilipak.i...@gmail.com>: > >> What is it that you want to know? > >> > > > > I think I like to try and see bigger picture behind acronyms. > > What acronyms? > SAR, DAR, PAR ..... > > At least this page explains how some 640*480 files might be born (it > > should be 486, but some lines are cut). > I just found some intersection between topic of this thread (sntsc - square pixels NTSC) and oroblem we facing. Thanks for bring it up. > Nonsense. If you're referring to DVD, there's no such thing as 640x480. > There's 720x480. It decodes to 720x540. > > > https://lurkertech.com/lg/video-systems/#480i > > Total Lines Per Frame 525. Nobody has those TVs anymore. > > > This is all interesting and not really theoretical to me because at least > > one our user still have a lot of HDV and DV material and he hopes to get > > correct encoding results in those cases too! > > Sorry, I can't help there. I don't know what HDV & DV are. DV in this context digital video as recorded by early camcoders. HDV is from early mpeg2 tape-based cameras. Is your friend trying to make a standards > compliant DVD or BD? No? Then the correct encoding results are whatever > can do the capture or the > remux or the transcoding. > > I assume HDV & DV are analog, otherwise, why are you fussing about 704 & > 525? If HDV & DV are > digital, then 704 & 252 don't apply. > > All that analog capture stuff is moot. Get everything you can and then use > ffmpeg to crop to > whatever the image is. As long as the capture hardware is running at > 60/1.001 fields per second, the > field-to-field images should be stable and you'll be fine. If the videos > are hand held camcorder, > then the images will not be stable, but there are stabilizers you can use. > Just get the images, then > worry about presentation. > Well, here lies the problem for us! Ffmpeg (command line utility) encodes those files straight away, so for example VLC displays them correctly. But our software (cinelerra-gg) so far was not setting st->sample_aspect_ratio so say webm encodes were by default with wrong Display aspect ratio in both VLC and GNOME filemanager previews. I hope now (after my patches under testing) we set sample aspect ratio in both places (codecpar and st) so hopefully libav* based players will display them correctly out of the box. > > _______________________________________________ > 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". > _______________________________________________ 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".