Outstanding, thanks Christopher! On May 26, 2010, at 23:04:52, Christopher Wright wrote:
>> Can someone tell me, in high-level terms, how I would do this? A QCRenderer >> seems obviously necessary. I saw a sample app that exports TIFF files for >> each frame, perhaps I can start with that and create an H.264 movie (would I >> use CoreVideo for that?). I suppose the best thing is to synchronously >> process the input movie, controlling the time base, but I'm not sure how to >> do that; the end result I want is to process each frame of the input movie >> separately. > > * Open the movie using QuickTime/QTKit > * Open output movie for editing (using QuickTime/QTKit) > * foreach(frame in movie) > * extract output frame > * drive QC renderer using movie output frame as input > * get output (-snapshotImageOfType:) > * add to output movie > * Then do some tricks to get the audio tracks form the source movie to > the destination (you should ask on the QuickTime list for the details of that > sort of stuff). > * If you want to be polite, you could also add other non-video tracks > (subtitles, chapters, etc). > * If you get too far along in this, you'll soon find that a movie can > actually have several independent video tracks -- this can complicate things > (usually only 1 is enabled, which makes your life much easier, but that's not > always the case). > > You can extract arbitrary frames from a QTMovie regardless of time, and you > can drive the composition's clock off of the frame's reported display time > (so that the composition "plays" at the same rate as the movie) -- this makes > it possible to work off-line (where you don't have to decode -> render -> > encode in realtime, which is difficult for higher quality codecs) > > CoreVideo isn't likely to help you much here -- movie input/output is pretty > much exclusively done through QuickTime/QTKit. > > > _______________________________________________ Do not post admin requests to the list. They will be ignored. Quartzcomposer-dev mailing list ([email protected]) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/quartzcomposer-dev/archive%40mail-archive.com This email sent to [email protected]
