> On Apr 13, 2024, at 01:57, bbb <[email protected]> wrote: > > Sorry for bothering you. It only behaves like this when I use "-codec copy". > Without that option it accepts the exact time I've specified. > > On 4/13/24 13:47, bbb wrote: >> I want to cut off the start of a video. When I tell ffmpeg to start at an >> exact time, it refuses to do so and instead starts at a time that's somehow >> "convenient" for ffmpeg. I can only assume that it's probably depending on >> something like a keyframe or an important frame for the compression >> algorithm but I don't really know. >> >> the command: >> ffmpeg -ss 0:32.08 -i video.mkv -codec copy -map 0 video.cut.mkv >> makes the output start around 0:31 (even when I change the parameter value a >> bit, the result is exactly the same). >> >> Is there a way to make ffmpeg start at the exact time that I specified? >> Does it maybe depend on the codec and would it help if I recode it before >> cutting? >> >> It would be even better if I were able to start at a specific frame number >> but I didn't find a parameter to set that. To set a frame offset seems only >> possible when you're exporting to images. >> _______________________________________________
I think this has everything you need to know. Bottom line as I understand it: it’s not possible to cut video precisely while copying streams. https://trac.ffmpeg.org/wiki/Seeking _______________________________________________ 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".
