Inside Macintosh: QuickTime Components

Importing a Scrapbook File

Before the import operation begins, the client may set the duration of samples to be added by the movie data import component by calling the MovieImportSetDuration function (described on [link] ).

The MovieImportFile function (described on [link] ) performs the import operation. The tasks involved in importing the data include

opening the source file
retrieving the first sample in order to determine the track dimension
creating a new track and media
determining the frame duration
setting up a sample description structure
cycling through all the frames in the Scrapbook and adding them to the new media
adding the new media to the track
closing the source file

Listing 0-32 supplies an example in which a Scrapbook file is imported.

Listing 32 Importing a Scrapbook file



 
/* if this function is called, it provides a hint from the caller as to the desired sample 

(frame) duration in the new media */



 
pascal ComponentResult ImportScrapbookSetSampleDuration

                                         (ImportScrapbookGlobals storage,

                                            TimeValue duration, 

                                            TimeScale scale)

{

    TimeRecord tr;

    tr.value.lo = duration;

    tr.value.hi = 0;

    tr.scale = 0;

    tr.base = nil;

    ConvertTimeScale (&tr, kMediaTimeScale);

                    /* your new media will have a time scale of 600 */

    (**storage).frameDuration = tr.value.lo;



 
    return noErr;

}

pascal ComponentResult ImportScrapbookFile

                                    (ImportScrapbookGlobals storage,

                                     FSSpec *theFile, Movie theMovie,

                                     Track targetTrack, Track *usedTrack,

                                     TimeValue atTime, 

                                     TimeValue *addedTime, 

                                     long inFlags, long *outFlags)

{

    OSErr err;

    short resRef = 0, saveRes = CurResFile();

    PicHandle thePict;

    Rect trackRect;

    short pageIndex = 0;

    Track newTrack = 0;

    Media newMedia;

    Boolean endMediaEdits = false;

    TimeValue frameDuration;

    SampleDescriptionHandle sampleDesc = 0;



 
    *outFlags = 0;

    if (inFlags & movieImportMustUseTrack)

        return invalidTrack;



 
    /* open source file */

    resRef = FSpOpenResFile (theFile, fsRdPerm);

    if (err = ResError()) goto bail;

    UseResFile(resRef);



 
    /* get the first PICT to determine the track size */

    thePict = (PicHandle)Get1IndResource ('PICT', 1);

    if (!thePict) {

        err = ResError();

        goto bail;



 
    }

    trackRect = (**thePict).picFrame;

    OffsetRect(&trackRect, -trackRect.left, -trackRect.top);



 
    /* create a track and PICT media */

    newTrack = NewMovieTrack (theMovie, trackRect.right << 16,

                                     trackRect.bottom << 16, kNoVolume);

    if (err = GetMoviesError()) goto bail;

    newMedia = NewTrackMedia (newTrack, 'PICT', kMediaTimeScale,

                                     nil, 0);

    if (err = GetMoviesError()) goto bail;

    if (err = BeginMediaEdits (newMedia)) goto bail;

    endMediaEdits = true;



 
    /* determine the frame duration (check the hint you may 

        have been called with) */

    frameDuration = (**storage).frameDuration;

    if (!frameDuration) frameDuration = kMediaTimeScale/5;

                                        /* default is 1/5th second */



 
    /* set up a simple sample description */

    sampleDesc = (SampleDescriptionHandle) NewHandleClear 

                                            (sizeof (SampleDescription));

    (**sampleDesc).descSize = sizeof(SampleDescription);

    (**sampleDesc).dataFormat = 'PICT';



 
    /* cycle through all source frames and add them to the media */

    do {

        Handle thePict; 

        short resID = pageToMapIndex (++pageIndex, 

                                                *GetResource ('SMAP', 0));



 
        if (resID == 0) break;

        thePict = Get1Resource ('PICT', resID);

        if (thePict == nil) continue;           /* some pages may not 

                                                    contain a 'PICT' */



 
        err = AddMediaSample(newMedia, thePict, 0, 

                                    GetHandleSize (thePict),

                                     frameDuration, sampleDesc, 1, 0, nil);



 
        ReleaseResource (thePict);

        DisposeHandle (thePict);

    } while (!err);

    if (err) goto bail;



 
    /* add the new media to the track */

    err = InsertMediaIntoTrack (newTrack, 0, 0, 

                                        GetMediaDuration (newMedia), kFix1);



 
bail:

    if (resRef) CloseResFile (resRef);

    if (endMediaEdits) EndMediaEdits (newMedia);

    if (err && newTrack) {

        DisposeMovieTrack (newTrack);

        newTrack = 0;

    }

    UseResFile (saveRes);

    if (sampleDesc) DisposeHandle ((Handle)sampleDesc);

    *usedTrack = newTrack;



 
    return err;

}



 
/* map from a Scrapbook page number to a resource ID */

short pageToMapIndex (short page, Ptr map)

{

    short mapIndex;

    for (mapIndex = 0; mapIndex < 256; mapIndex++)

        if (*map++ == page)

            return mapIndex | 0x8000;

    return 0;

}