QuickTime 4 Reference
Setting up an Effect Description

The first step is to provide an effect description. The code shown in Listing 7 is very similar to the code described in "Creating an Effect Description" .
Listing 7 Providing an effect description


 
{

    QTAtomContainer     myEffectDesc = nil;

    OSType              myType;

    OSErr               myErr = noErr;

    long                myLong;



    // Create a new, empty effect description

    myErr = QTNewAtomContainer(&myEffectDesc);



    // This example is an effect description for an SMPTE effect

    myType = OSTypeConst('smpt');

    myErr = QTInsertChild(myEffectDesc,

                    kParentAtomIsContainer,

                    kParameterWhatName,

                    kParameterWhatID,

                    0,

                    sizeof(myType),

                    &myType,

                    nil);



    // Now reference the two sources to be used. These will not be items 

    // in an input map. Instead the source names used will be resolved in

    // the decompression sequence.

    myType = OSTypeConst('srcA');

    myErr = QTInsertChild(myEffectDesc,

                    kParentAtomIsContainer,

                    kEffectSourceName,

                    1,

                    0,

                    sizeof(myType),

                    &myType,

                    nil);



    // Add the second source

    myType = OSTypeConst('srcB');

    myErr = QTInsertChild(myEffectDesc,

                    kParentAtomIsContainer,

                    kEffectSourceName,

                    2,

                    0,

                    sizeof(myType),

                    &myType,

                    nil);



    // This example uses SMTPE effect number 74, so add a WipeID

    // parameter with the value 74

    myLong = 74;

    myErr = QTInsertChild(myEffectDesc,

                    kParentAtomIsContainer,

                    OSTypeConst('wpID'),

                    1,

                    0,

                    sizeof(myLong),

                    &myLong,

                    nil);

}