Alexandros Drymonitis wrote: > If you are aiming to JUMP to specific frames in > > the video or play it backwards you would choose a different codec > > than if you just want to play it from the beginning to the end > > linearly. > > Could you give some examples? I don't know anything about this but would > really like to. Could you explain why is it like this?
This is because with some codecs, to save storage space/bandwidth, movies are made of a few full images (key frames), and partial images that hold only the difference with respect to the previous keyframe. Say there is 1 full frame for 24 partial frame. So if you jump to a partial frame, the computer has to seek to a keyframe and then to the diff frame, and rebuild the complete image from that. mjpeg is just more or less a series of JPEG images in a queue. So when you seek to frame x, there is less work to do. The downside is that files are very large. If you just read a movie linearly, you're good with keyframes and so. If you want to jump all over the file like crazy, it could be more efficient with mjpeg. _______________________________________________ Pd-list@iem.at mailing list UNSUBSCRIBE and account-management -> http://lists.puredata.info/listinfo/pd-list
