On Thu, Oct 10, 2019 at 19:45:41 +0200, FFmpeg user discussions wrote: > But it is strange anyway: > > _ffmpeg.exe -i _audio.flac -t 10 -codec copy _audio_2.flac > —> it shows me 9.98 > _ffmpeg.exe -i audio_2.flac -f null - > —> but encode is 10.08 > > _ffmpeg.exe -i _audio.flac -t 20 -codec copy _audio_2.flac > —> it shows me 19.96 > _ffmpeg.exe -i audio_2.flac -f null - > —> but encode is 20.06 > > And so on ... > > But: > _ffmpeg.exe -i _audio.flac -t 10 -codec flac _audio_2.flac > —> 10.00 > Always accurate.
With stream copy, ffmpeg will (I guess) cut at nearest audio packet borders. When re-encoding, it can cut at the exact sample. Considering that FLAV packets usually contain a lot of samples (I believe I saw some ffmpeg default of 4096 samples per packet?), the packet's size will obviously determine the possible precision. This happens with ther codecs as well, I have experienced it quite often. (I don't know why encode and decode have a different opinion regarding the length, though.) Cheers, Moritz _______________________________________________ ffmpeg-user mailing list email@example.com https://ffmpeg.org/mailman/listinfo/ffmpeg-user To unsubscribe, visit link above, or email ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe".