// create and add the input map - this tells the effect

    // which tracks in the movie are affected

        long                myRefIndex1, myRefIndex2;

        QTAtomContainer     myInputMap;

        QTAtom              myInputAtom;

        OSType              myInputType;

        long                myLong;

        QTNewAtomContainer(&myInputMap);

        // first input

        if (videoTracks[0]) {

            // setup a reference between our effect and the first input track

            AddTrackReference(videoTrackFX, videoTracks[0], kTrackModifierReference, &myRefIndex1);

            QTInsertChild(myInputMap, kParentAtomIsContainer, kTrackModifierInput, myRefIndex1, 0, 0, NULL, &myInputAtom);

            // add modifier track type ('vide')

            myInputType = EndianU32_NtoB(kTrackModifierTypeImage);

            QTInsertChild(myInputMap, myInputAtom, kTrackModifierType, 1, 0, sizeof(myInputType), &myInputType, NULL);

            // source name for first source - there is a corresponding

            // kEffectSourceName atom in the effect description to 

            // identify the source

            myLong = EndianU32_NtoB(kSourceOneName);

            QTInsertChild(myInputMap, myInputAtom, kEffectDataSourceType, 1, 0, sizeof(myLong), &myLong, NULL);

        }

        // second input

        if (videoTracks[1]) {

            // setup a reference between our effect and the second input track

            AddTrackReference(videoTrackFX, videoTracks[1], kTrackModifierReference, &myRefIndex2);

            QTInsertChild(myInputMap, kParentAtomIsContainer, kTrackModifierInput, myRefIndex2, 0, 0, NULL, &myInputAtom);

            //  modifier track type ('vide')

            myInputType = EndianU32_NtoB(kTrackModifierTypeImage);

            QTInsertChild(myInputMap, myInputAtom, kTrackModifierType, 1, 0, sizeof(myInputType), &myInputType, NULL);

            // source name for second source - there is a corresponding

            // kEffectSourceName atom in the effect description to

            // identify the source

            myLong = EndianU32_NtoB(kSourceTwoName);

            QTInsertChild(myInputMap, myInputAtom, kEffectDataSourceType, 1, 0, sizeof(myLong), &myLong, NULL);

        }