On Dec 28, 2007, at 3:57 PM, Nathaniel Gottlieb-Graham wrote:
I may be daft, but there doesn't seem to be any way to create a
QTTrack with a movie in it. The only real way that I can see to add
anything to a QTTrack is the addImage:forDuration:withAttributes:
method, which takes NSImages, and can't be fed QTMovies or anything
like that. Am I just missing something obvious, or will I have to
resort to some ugly hack like adding a new track for every image of
a movie I want to overlay?
Hello,
I think it might be best to reconsider your understanding of QuickTime
Tracks. QuickTime movies have tracks that are composed of "samples" of
a particular type per track. So, there are VideoTracks, Audio tracks,
Text tracks, etc. It's unclear what your goal is, but if you wanted to
get the content of one movie and put it in another, you would create a
QTTrack of that particular media type in the result movie, then copy
the samples of the source track in the source movie to the new track.
You would have to do this with each track in the movie that you wanted
the content of. Below is an example for audio tracks...
for (i = 0; i > [audioTracks count], i++)
{
Track sourceTrack = [[audioTracks objectAtIndex: i]
quickTimeTrack];
Track outTrack = NewMovieTrack([outMovie quickTimeMovie], 0, 0,
GetTrackVolume(sourceTrack));//copy the volume over..
Media sourceMedia = NewTrackMedia(outTrack, SoundMediaType,
[[inMovie attributeForKey: QTMovieTimeScaleAttribute] longValue],
NULL, 0);
error = BeginMediaEdits(sourceMedia);
error = InsertTrackSegment(sourceTrack, outTrack,
GetTrackOffset(sourceTrack), GetTrackDuration(sourceTrack), 0);//
insert it at the start of the Dest movie..
error = EndMediaEdits(sourceMedia);
error = CopyTrackSettings(sourceTrack, outTrack);//make the
track settings the same..
}
return error;
}
QTTrack is not very limited at all. In fact, each release of the
framework provides more and more functionality For example, you can
now add Chapters to a QTMovie with a single addChapter call. Sometimes
developers have to revert to the Track primitive. That's becoming
rarer and rarer though.
hope that helps. This should actually move to the QuickTime list though.
