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 20-8 creates a sample description that selects Apple's SMPTE Wipe (`smpt' ) effect.

Listing 8 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);

}