Reimar Döffinger <[email protected]> added the comment: On Mon, Dec 07, 2009 at 03:54:41PM +0000, Greg Maxwell wrote: > Greg Maxwell <[email protected]> added the comment: > > Just FYI— > > "MPEG input unfortunately is essentially variable frame-rate data, which > for what I can tell is not possible to encode with libtheora." > > VFR for Ogg/Theora is done by setting the frame rate to the > lowest-common-denominator of the rates, or a suitably high value (like 1000) > and > inserting zero byte frames for the non-existing frames.
I think you completely misunderstood the issue. You explain how Ogg supports variable frame-rate (and if that's called support, AVI supports it as well, but no matter). However the point is the Theora encoder, it seems to have no way of passing timestamps to the encoder. With your method, if I set the time base to 1000 for the encoder but the video actually was only 10 fps, the encoded video would have a bitrate too low by a factor 100! That's completely unusable. And even if I ignored that, the timestamps for B-frames (assuming Theora has those, I just realize it might not) still would be off, since they aren't reordered. _____________________________________________________ FFmpeg issue tracker <[email protected]> <https://roundup.ffmpeg.org/roundup/ffmpeg/issue1197> _____________________________________________________
