QuickTime 3 Reference

Preparing the Sample Description

Next, a sample description is prepared. This is identical to the sample description that would be prepared if the same effect was added to a QuickTime movie. The code in Listing 13 creates a sample description that selects Apple's SMPTE wipe ('smpt' ) effect.

Listing 13 Preparing a Sample Description



 
{

    ImageDescriptionHandlemySampleDesc = NULL;



    // create a new, empty sample description

    mySampleDesc =

        (ImageDescriptionHandle)NewHandleClear(sizeof(ImageDescription));



    // fill in the fields of the sample description

    (**mySampleDesc).idSize             = sizeof(ImageDescription);

    (**mySampleDesc).cType              = 'smpt';

    (**mySampleDesc).vendor             = kAppleManufacturer;

    (**mySampleDesc).temporalQuality    = codecNormalQuality;

    (**mySampleDesc).spatialQuality     = codecNormalQuality;

    (**mySampleDesc).width              = theWidth;

    (**mySampleDesc).height             = theHeight;

    (**mySampleDesc).hRes               = 72L << 16;

    (**mySampleDesc).vRes               = 72L << 16;

    (**mySampleDesc).frameCount         = 1;

    (**mySampleDesc).depth              = 0;

    (**mySampleDesc).clutID             = -1;



    return(mySampleDesc);

}