QuickTimeUtils.c

/*
	File:		QuickTimeUtils.c
	
	Description: Misc. QuickTime Utilities

	Author:		Apple DTS

	Copyright: 	© Copyright 2005 Apple Computer, Inc. All rights reserved.
	
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	Change History (most recent first):

*/

#include "QuickTimeUtils.h"

//////////
//
// MovieHasSoundTrack
// Determine whether a movie contains a sound track.
// 
//////////

Boolean MovieHasSoundTrack (Movie theMovie)
{
	return(GetMovieIndTrackType(theMovie, 1, AudioMediaCharacteristic, movieTrackCharacteristic | movieTrackEnabledOnly) != NULL);
}


//////////
//
// GetMovieExtractionDuration
//
// Determine the movie audio extraction duration which is
// the duration of the longest sound track in the movie.
//
// Note this is different than the movie duration, which is
// the duration of the entire movie irrespective of how long 
// any sound tracks in the movie may be. For example, a given
// sound track in the movie may only have a duration equal to 
// half the length of the actual movie. In this case, we would
// want to stop audio extraction at the end of the sound track
// duration, not at the end of the movie duration
// 
//////////

Float64 GetMovieExtractionDuration (Movie theMovie)
{
    TimeValue maxDuration = 0;
    UInt8 i;

    SInt32 trackCount = GetMovieTrackCount(theMovie);

    if (trackCount) 
    {
        for (i = 1; i < trackCount + 1; i++) 
        {
            Track aTrack = GetMovieIndTrackType(theMovie,
                                                i,
                                                SoundMediaType,
                                                movieTrackMediaType);
            if (aTrack) 
            {
                TimeValue aDuration = GetTrackDuration(aTrack);

                if (aDuration > maxDuration) maxDuration = aDuration;
            }
        }

        return ((Float64)maxDuration / (Float64)GetMovieTimeScale(theMovie));
    }
    return 0.;
}