Developer CD Series 1998 August: Tool Chest/Dev.CD Aug 98 TC.toast/Sample Code/QuickTime/Show Movie/Sources/MovieStuff.c

Text File | 1995-11-20 | 30.6 KB | 984 lines | [TEXT/MMCC]

/*
  File:            MovieStuff.c
  Contains:         movie handling routines
  Written by:    Jason Hodges-Harris & Don Swatman
  Copyright:    © 1995 by Apple Computer, Inc., all rights reserved.
*/

//==============================================
// MovieStuff.c
//
// This handles all the clever movie stuff.
// - Sets up movie windows
// - Tears down movie windows
// - handles updates and events
// - handles slaving, altering playback speed, looping etc
//==============================================

#include <Memory.h>
#include <TextUtils.h>
#include <Movies.h>

#include "MovieStuff.h"
#include "WindStuff.h"

//==============================================
//  CallBackInfoType
//
// This structure is used to store QuickTime
// call backs and any data they require.
// - It has a several parameters at the front,
//   then a variable size record at the end. It also
//   needs the parameters used in CallMeWhen
// - It's size is:
//      "sizeof(CallBackInfoType) + callBackDataSize - sizeof(long)"
// - Data should not contain the only reference
//   to other handles, as it can't dispose of them
// - It forms a linked list. Any new items are
//   added to the front.
// - It should be passed in the call backs
//   reference field.
//==============================================

struct CallBackInfoType
{
    struct CallBackInfoType **hNextCallBackInfo; // Next in the list

    QTCallBack actualCallBack;    // the call back
    WindowPtr  pParentWindow;     // parent window of the movie
    long       param1;            // Used in "CallMeWhen"
    long       param2;            // Used in "CallMeWhen"
    long       param3;            // Used in "CallMeWhen"
    long       callBackDataSize;  // Size of the data attached on the end
    long       callBackDataStart; // where the data starts
};

typedef struct CallBackInfoType CallBackInfoType,
    *CallBackInfoPtr, **CallBackInfoHdl;

//==============================================
//  DocMovieInfoType
//
// Used to hold information about a movie within
// a window
// - It should be attached to the windows RefCon
//==============================================

struct DocMovieInfoType
{
        FSSpec          movieFileSpec;  // movies File Spec
        MovieController movieControls;    // standard movie controller
        Movie           actualMovie;        // the Movie itself!
        Boolean         movieAutoClose; // True if the window closes after movie finishes
        TimeBase              moviesTimeBase;
        TimeScale              moviesTimeScale;
        CallBackInfoHdl hFirstCallBackData; // Handle to first item of the call back info list
        WindowPtr       pSlaveWind;     // WindowPtr of this movies slave
};

typedef struct DocMovieInfoType DocMovieInfoType,
    *DocMovieInfoPtr, **DocMovieInfoHndl;

//==============================================
// Global Stuff, init and tear down
//==============================================

// Prototypes of functions  used in UPPs
pascal void StartMovieCB(QTCallBack myCallBack,long ref);
pascal void AlterRate( QTCallBack myCallBack,long ref);
pascal void AlterMasterOffset( QTCallBack myCallBack,long ref);

// Global UPPs
QTCallBackUPP        gStartMovieCBUpp;
QTCallBackUPP        gAlterRateUpp;
QTCallBackUPP        gAlterMasterOffsetUpp;

//----------------------------------------------
// InitMovieGlobals
//
// Init's any globals used in MovieStuff
// i.e. the UPPs
//----------------------------------------------
void InitMovieGlobals(void)
{
    gStartMovieCBUpp = nil;
    gAlterRateUpp    = nil;
    gAlterMasterOffsetUpp = nil;

//    Create routine descriptor for "StartMovieCB" QT callback routine
    gStartMovieCBUpp = NewQTCallBackProc(StartMovieCB);

//    Create routine descriptor for "AlterRate" QT callback routine
    gAlterRateUpp = NewQTCallBackProc(AlterRate);

//    Create routine descriptor for "AlterMasterOffset" QT callback routine
    gAlterMasterOffsetUpp = NewQTCallBackProc(AlterMasterOffset);

}

//----------------------------------------------
// KillMovieGlobals
//
// Removes the UPPs
//----------------------------------------------
void KillMovieGlobals(void)
{
// Clear the Universal Proc Pointers
//    You don't need to do this as quiting the app will do it for you,
//    however, I have this thing about neatness.
    if (gStartMovieCBUpp)
        DisposeRoutineDescriptor(gStartMovieCBUpp);
    if (gAlterRateUpp)
        DisposeRoutineDescriptor(gAlterRateUpp);
    if (gAlterMasterOffsetUpp)
        DisposeRoutineDescriptor(gAlterMasterOffsetUpp);

}


//==============================================
//
// Error Reporting
//
//==============================================

//----------------------------------------------
// Report Error
//
// If an error occurs, Uses DebugStr to send out
// some text passed to it, then the error number
//----------------------------------------------

void ReportError( Str255 errText, OSErr theErr );
void ReportError( Str255 errText, OSErr theErr )
{
    Str255 errorStr;

// Check there is an error
    if (theErr)
    {
// convert theErr number to text
        NumToString(theErr,errorStr);

// if there is error text then displat it
        if (errText != "\p")
            DebugStr(errText);
// Display error number
        DebugStr(errorStr);
    }
}

//----------------------------------------------
// GetAndReportError
//
//   Checks GetMoviesError and reports error if
// needed
//----------------------------------------------
OSErr GetAndReportError( Str255 errText );
OSErr GetAndReportError( Str255 errText )
{
    OSErr  theErr;

    theErr = GetMoviesError();       // Get Movies error number
    ReportError( errText, theErr );  // And report it
    return(theErr);                  // Oh yeh, return it to the caller
}

//==============================================
//
// Call Back info stuff
//
// Following routines handle the CallBackInfoHdl
// structure.
//==============================================

//----------------------------------------------
// AddNewCallBackInfo
//
//  Creates a new "CallBackInfoHdl", intialises and
//    returns it
// - It puts "pWindow" and "theCallBack" into the structure
// - It appends "dataSize" bytes of data from "pDataStart"
//   on to the end of the structure
//----------------------------------------------

CallBackInfoHdl AddNewCallBackInfo( WindowPtr  pWindow,
                                                                        QTCallBack theCallBack,
                                                                        Ptr        pDataStart,
                                                                        long       dataSize,
                                                                        long       param1,
                                                                        long       param2,
                                                                        long       param3
                                                                    );
CallBackInfoHdl AddNewCallBackInfo( WindowPtr  pWindow,
                                                                        QTCallBack theCallBack,
                                                                        Ptr        pDataStart,
                                                                        long       dataSize,
                                                                        long       param1,
                                                                        long       param2,
                                                                        long       param3
                                                                    )
{
    CallBackInfoHdl  hNewCBInfo = nil;  // the new call back info record
    DocMovieInfoHndl hDocMovieInfo;
    long newSize;   // Size of hNewCBInfo and the data added to it

// Calculate how big the block needs to be
    newSize = sizeof(CallBackInfoType) + dataSize - sizeof(long);

// Create the call back data item
    hNewCBInfo = (CallBackInfoHdl) NewHandle (newSize);

// Check that we actualy did create it!
    if (hNewCBInfo)
    {

// Setup the structure

        (**hNewCBInfo).hNextCallBackInfo = nil;
        (**hNewCBInfo).actualCallBack    = theCallBack;
        (**hNewCBInfo).pParentWindow     = pWindow;
        (**hNewCBInfo).param1 = param1;
        (**hNewCBInfo).param2 = param2;
        (**hNewCBInfo).param3 = param3;
        (**hNewCBInfo).callBackDataSize  = 0;

// Add in the data (if there is any)

        if (dataSize && pDataStart)
        {
            (**hNewCBInfo).callBackDataSize  = dataSize;
            BlockMove( pDataStart, &((**hNewCBInfo).callBackDataStart), dataSize);
        }

// Now, link it into the window data structure (attach it to the front of the chain)

        hDocMovieInfo = (DocMovieInfoHndl)GetWRefCon ( pWindow );
        (**hNewCBInfo).hNextCallBackInfo     = (**hDocMovieInfo).hFirstCallBackData;
        (**hDocMovieInfo).hFirstCallBackData = hNewCBInfo;
    }

    return( hNewCBInfo );
}

//----------------------------------------------
//  RemoveCallBackInfo
//
//  Scans down the CallBackInfoHdl chain and disposes
// of each one
//----------------------------------------------

void RemoveCallBackInfo ( CallBackInfoHdl hFirstItem );
void RemoveCallBackInfo ( CallBackInfoHdl hFirstItem )
{
    CallBackInfoHdl  hNextCBInfo;
    CallBackInfoHdl  hDisposeData;

    if (hFirstItem)
    {
// Scan down the chain of items, disposing as we go
        hNextCBInfo = hFirstItem;
        while (hNextCBInfo)
        {
            hDisposeData = hNextCBInfo;
            hNextCBInfo  = (**hNextCBInfo).hNextCallBackInfo;

        // Dispose of the call back
            DisposeCallBack( (**hDisposeData).actualCallBack );

        // Dispose of the call back info block
            DisposeHandle( (Handle) hDisposeData);
        }
    }

}

//----------------------------------------------
//  GetDataFromCBInfo
//
// Extracts the data from a CallBackInfoHdl and
// moves the data into it. Checks the stored structure
// is smaller than requested size. Ideally they should
// be the same size.
//----------------------------------------------

Boolean GetDataFromCBInfo ( CallBackInfoHdl  hCallBackInfo,
                                                        Ptr    pData,
                                                        long   maxDataSize   );
Boolean GetDataFromCBInfo ( CallBackInfoHdl  hCallBackInfo,
                                                        Ptr    pData,
                                                        long   maxDataSize   )
{
    Boolean isOk = false;

// Check that we have a call back,
//                     and we have some where to put the data,
//                         and it's bigger than 0
    if (hCallBackInfo && pData && maxDataSize)

// Check the call back data is smaller than the new structure
        if ( (**hCallBackInfo).callBackDataSize  <= maxDataSize)
        {

// Move the data to pData
            BlockMove ( &((**hCallBackInfo).callBackDataStart),
                                    pData,
                                    (**hCallBackInfo).callBackDataSize );
            isOk = true;
        }
    return ( isOk );
}

//----------------------------------------------
//  IsMoviePlaying
//
// Find out if any movie is playing
//----------------------------------------------

Boolean IsMoviePlaying (void)
{
    DocMovieInfoHndl hDocMovieInfo; // The movie we're checkings info
    Boolean movieLive = false; // set to true if there is a live window
    short   windCount;

// Scan the window list until we've found a live window
    for (windCount = 0;(windCount < kMaxWindows) && !movieLive; windCount++ )
// If this window is open
        if (gTheWinds[windCount])
            {
// Get information about the movie
                hDocMovieInfo = (DocMovieInfoHndl)GetWRefCon (gTheWinds[windCount]);

// Use IsMovieDone to see if it's still running
                if (!IsMovieDone((**hDocMovieInfo).actualMovie) )
                    movieLive = true;
            }
    return (movieLive);
}

//----------------------------------------------
// UpdateMovieWindow
//----------------------------------------------
void UpdateMovieWindow (  WindowPtr pWindow   )
{
// Get the movie from the ref con and update it. Easy.
    UpdateMovie( (**(DocMovieInfoHndl)GetWRefCon( pWindow )).actualMovie);
}

//----------------------------------------------
// Load a movie into memory
//
//  Use standard file to get and load a movie
//----------------------------------------------
void    LoadOneMovie( DocMovieInfoHndl hDocMovieInfo );
void    LoadOneMovie( DocMovieInfoHndl hDocMovieInfo )
{
    Movie         myNewMovie = nil;   // The new movie
    StandardFileReply    newMovieFile;   // Standard File Reply about the  movies file
    Str255        myMovieName;        // The Movies name
    OSErr         error;
    SFTypeList    myTypes = {MovieFileType}; // File types we want Standard File to get
    short         myMovieResFile;     // Movie files ref number
    short         myMovieResID = 0;   // Load the first movie res
    Boolean       movieChanged;       // Set to true if movie was changed durring
                                                                        // loading to resolve references

// Use standard file to get the fsSpec etc.
    StandardGetFilePreview(nil,1,myTypes,&newMovieFile);
    if (newMovieFile.sfGood)
    {
// Open the movie file
        error = OpenMovieFile( &newMovieFile.sfFile, &myMovieResFile, fsRdPerm);
        if (error==noErr)
        {
// Store the file spec
            (**hDocMovieInfo).movieFileSpec = newMovieFile.sfFile;

// Move Movie data in to memory
            error = NewMovieFromFile( &myNewMovie, myMovieResFile, &myMovieResID,
                                      myMovieName, newMovieActive, &movieChanged);

// Close the file as we succeded in opening it
            CloseMovieFile (myMovieResFile);
        }
    }
    (**hDocMovieInfo).actualMovie =    myNewMovie; // Return myNewMovie
}

//----------------------------------------------
// ServiceMovieTasks
//
// Used to Handle the null event. You need to handle
// this to make the movie play!
// - First it sees if the movie controller has an event
// - Scans the window list looking for movies
// - If the movie has finished then close it if the
//   flags are set that way
// - If any movies are active, then call MoviesTask
//   to make them play
// - Finally return true if the event was handled by the
//   movie controller
//----------------------------------------------
Boolean ServiceMovieTasks ( WindowPtr pWindow, const EventRecord *theEvent )
{
#pragma unused ( pWindow )

    Boolean doneProccessing = false;  // goes to true if MCIsPlayerEvent handles event
    DocMovieInfoHndl hDocMovieInfo;   // Current windows movie info
    short   windCount;
    Boolean needMovieTasks = false;   // Goes true if there is a movie running
    Boolean moviePlaying;

// Scan window list
    for (windCount = 0;windCount < kMaxWindows; windCount++ )
        if (gTheWinds[windCount])
            {
// Get movie information for this window
                hDocMovieInfo = (DocMovieInfoHndl)GetWRefCon (gTheWinds[windCount]);

// Handle any events to this windows movie controller if it's got one
                if (!doneProccessing)
                    if ((**hDocMovieInfo).movieControls)
                        if (MCIsPlayerEvent((**hDocMovieInfo).movieControls, theEvent))
                            doneProccessing = true;

// Next bit checks to see if a window has finished playing (by using
// IsMovieDone) and closes it if auto close has been set for it
                moviePlaying = !IsMovieDone((**hDocMovieInfo).actualMovie);
                if (   (**hDocMovieInfo).movieAutoClose && (!moviePlaying) )
                    CloseOurWindow( windCount );
                else
                    if (moviePlaying)
                        needMovieTasks = true; // Hey there's a movie running
            }

// If we have an active movie, then service all movies
    if (needMovieTasks)
        MoviesTask(nil,0);

    return ( doneProccessing );
}

//----------------------------------------------
//  CloseMovieWindow
//
// Close a movie window and destroys associated
// structures. If this is a Master window,
// sets "*pSlaveWindow" to the slave WindowPtr
//----------------------------------------------
OSErr CloseMovieWindow( WindowPtr pWindow,
                                                WindowPtr *pSlaveWindow )
{
    DocMovieInfoHndl hDocMovieInfo;

    *pSlaveWindow = nil;

// Get movie structure
    hDocMovieInfo = (DocMovieInfoHndl)GetWRefCon(pWindow);

    if (hDocMovieInfo)
    {
// Set the slave WindowPtr
        *pSlaveWindow = (**hDocMovieInfo).pSlaveWind;

// dispose movie
        DisposeMovie((**hDocMovieInfo).actualMovie);

// dispose of the controller if it exists
        if ((**hDocMovieInfo).movieControls)
            DisposeMovieController ( (**hDocMovieInfo).movieControls );

// dispose of call back structures
        RemoveCallBackInfo ( (**hDocMovieInfo).hFirstCallBackData );

// dispose movie structure
        DisposeHandle( (Handle)hDocMovieInfo );
    }
    return ( noErr );
}

//----------------------------------------------
//   OpenMovieWindow
//
// - Opens a movie
// - Creates and initialises the windows movie
//   structure "DocMovieInfoHndl"
// - Creates (if wanted) a movie controller
// - Sizes the window to fit the movie and controller
// - Shows the window
//----------------------------------------------
OSErr OpenMovieWindow ( WindowPtr pWindow,
                                                Boolean   doesAutoClose,
                                                Boolean   hasControler  )
{
    OSErr theErr = noErr;
    DocMovieInfoHndl hDocMovieInfo = nil; // new window movie information
    Rect moviesRect;   // Size of the movie
    Rect newWindRect;  // New Windows rect (movie + Controllers rect)

    if (!pWindow)
    {  // Error !!!!
        DebugStr("\pHey, this window doesn't exists!!");
        theErr = userCanceledErr;  // Should be something more appropriate
    }
    else
    {

// allocate new movie doc structure
        hDocMovieInfo = (DocMovieInfoType**) NewHandle (sizeof(DocMovieInfoType));
        if (hDocMovieInfo == nil)
        { // Error !!!!
            DebugStr("\pError allocating doc handle");
            theErr = userCanceledErr;  // Should be something more appropriate
        }
        else
        {
// Set up the hDocMovieInfo record
            (**hDocMovieInfo).movieAutoClose = doesAutoClose;
            (**hDocMovieInfo).hFirstCallBackData  = nil;
            (**hDocMovieInfo).movieControls = nil;
            (**hDocMovieInfo).actualMovie   = nil;
            (**hDocMovieInfo).pSlaveWind    = nil;

// set window refcon to movie doc handle
            SetWRefCon( pWindow, (long)hDocMovieInfo );
            SetPort(pWindow);

// load movie refs into doc structure
            LoadOneMovie ( hDocMovieInfo );
            if ((**hDocMovieInfo).actualMovie == nil)
            { // Cancel button pressed or Error !!!!
                theErr = userCanceledErr;  // Should be something more appropriate
                return(theErr);
            }
            else
            {
// get timebase from movie
                (**hDocMovieInfo).moviesTimeBase = GetMovieTimeBase((**hDocMovieInfo).actualMovie);
                theErr = GetAndReportError( "\pError!! GetMovieTimeBase");

// get timescale from movie
                if (!theErr)
                {
                    (**hDocMovieInfo).moviesTimeScale = GetMovieTimeScale((**hDocMovieInfo).actualMovie);
                    theErr = GetAndReportError( "\pError!! Getting movie time scale");
                }

                if (!theErr)
                    if (!hasControler)
                    {
    // Don't want a controller, so just
        // Get movies rect as this is the size of the window
                        GetMovieBox((**hDocMovieInfo).actualMovie, &newWindRect);
                    }
                    else
                    {
    // We want a movie controller so create it beneath the movie
        // Get the movies rect as this is the size we want to put it in
                        GetMovieBox((**hDocMovieInfo).actualMovie, &moviesRect);

        //Create a controller and put below the movie. as moviesRect is the size of the movie,
        // the controller will fall outside the rect
                        (**hDocMovieInfo).movieControls = NewMovieController ( (**hDocMovieInfo).actualMovie,
                                                                                                                                     &moviesRect,
                                                                                                                                     mcTopLeftMovie);
                        if ((**hDocMovieInfo).movieControls == nil)
                        { // Failed to create controller Error !!!!
                            theErr = userCanceledErr;  // Should be something more appropriate
                            return(theErr);
                        }
                        else
                        {
    // Get movieControllers rect. Because it is attached the movie, it will return
    // the controller and movies size
                            theErr = MCGetControllerBoundsRect((**hDocMovieInfo).movieControls, &newWindRect);
                        }
                    }

                if (!theErr)
                {
    // Size the window to fit the movie and controller
                    SizeWindow( pWindow,newWindRect.right, newWindRect.bottom,true);
                }
            }
        }
    }

    return ( theErr );
}

//==============================================
// The time base call back procs
//==============================================

//----------------------------------------------
//   AlterMasterOffset
//
// QuickTime callback used to set the SetTimeBaseValue.
// - Can be used to make the movie loop.
// - Takes a value in seconds in the data of
//   the CallBackInfoHdl passed in "ref"
//----------------------------------------------

pascal void AlterMasterOffset(QTCallBack myCallBack,long ref)
{
    DocMovieInfoHndl hDocMovieInfo;
    WindowPtr pWindow;
    TimeValue newTimeValue; // Where we want to move to
    OSErr     theErr;

// Extract where we want to move to from (CallBackInfoHdl)ref
    if (GetDataFromCBInfo( ( CallBackInfoHdl)ref,
                                                 (Ptr) &newTimeValue, sizeof ( TimeValue ) ))
    {
        pWindow = (**(CallBackInfoHdl)ref).pParentWindow;  // Get the parent window
        hDocMovieInfo = (DocMovieInfoHndl)GetWRefCon ( pWindow ); // Get the movie info
// Move our position in the movie
        SetTimeBaseValue ( (**hDocMovieInfo).moviesTimeBase,
                                             newTimeValue,
                                             (**hDocMovieInfo).moviesTimeScale);
// Finally must reschedule the call back so that it happens again
        theErr = CallMeWhen ( myCallBack,
                                                    gAlterMasterOffsetUpp, ref,
                                                    (**(CallBackInfoHdl)ref).param1,
                                                    (**(CallBackInfoHdl)ref).param2,
                                                    (**(CallBackInfoHdl)ref).param3);
    }
}

//----------------------------------------------
//   AlterRate
//
// QuickTime callback used to set the movies rate.
// - Alters the speed of playback.
// - Takes a value in the data of the CallBackInfoHdl
//   passed in "ref"
//----------------------------------------------

pascal void AlterRate( QTCallBack myCallBack,long ref)
{
#pragma unused ( myCallBack )

    DocMovieInfoHndl hDocMovieInfo;
    WindowPtr pWindow;
    long      newMovieRate;

// Extract the new speed we want the movie to run at
    if (GetDataFromCBInfo ( ( CallBackInfoHdl)ref, (Ptr) &newMovieRate, sizeof ( long ) ))
    {
        pWindow = (**(CallBackInfoHdl)ref).pParentWindow;  // Get the parent window
        hDocMovieInfo = (DocMovieInfoHndl)GetWRefCon ( pWindow ); // Get the movie info


// Change the movies rate
        SetMovieRate((**hDocMovieInfo).actualMovie, newMovieRate);
    }

    return;
}

//----------------------------------------------
//   StartMovieCB
//
// QuickTime callback used to start a movie.
// - Takes a value (Movie) in the data of the CallBackInfoHdl
//   passed in "ref" which is the movie you want to start.
//----------------------------------------------


pascal void StartMovieCB(QTCallBack myCallBack,long ref)
{
#pragma unused ( myCallBack )

    Movie movieToStart;

    if (GetDataFromCBInfo ( ( CallBackInfoHdl)ref, (Ptr) &movieToStart, sizeof ( Movie ) ))
    {
        SetMovieRate(movieToStart,65536);
    }
}

//==============================================
// Set up the various options
//==============================================

//----------------------------------------------
// SetupMovieRate
//
// - Sets up the call backs to change the play back speed
//   of the movie.
// - "delayBeforeChange" gives the time in seconds when
//   the first speed change happens or a constant that
//   tells it to change at 1/3 (& 2/3) of the movies
//   duration.
//----------------------------------------------

OSErr SetupMovieRate( WindowPtr pWindow,  short delayBeforeChange  )
{
    OSErr            theErr = noErr;
    QTCallBack             theNewCallBack;     // Call Back
    long                     theCallBackOffset;  // When we want to change the rate
    TimeValue               theMovieLen;        // Length of the movie
    DocMovieInfoHndl hDocMovieInfo;      // Info about the windows movie
    CallBackInfoHdl  hTempCallBackInfo;  // Call back information
    long             newMovieRate;       // What the new rate will be

    hDocMovieInfo = (DocMovieInfoHndl)GetWRefCon (pWindow);
    if (hDocMovieInfo != nil)
    {
// Set up the time base value
        SetTimeBaseValue( (**hDocMovieInfo).moviesTimeBase,
                                            0,
                                            (**hDocMovieInfo).moviesTimeScale);


// If we're changing by a thirds, we need the movie's length
        if (delayBeforeChange == kOneThird)
            theMovieLen  = GetMovieDuration((**hDocMovieInfo).actualMovie);

// ---- First call back - slow playback rate to x2 normal -----

// Work out length of delay before callbacks start
        if (delayBeforeChange == kOneThird)
            theCallBackOffset = theMovieLen*0.3333;
        else
            theCallBackOffset = delayBeforeChange * (**hDocMovieInfo).moviesTimeScale;

// Create a new call back
        theNewCallBack = NewCallBack((**hDocMovieInfo).moviesTimeBase,callBackAtTime);

        newMovieRate = 131072;        // speed up rate to x2 normal

// Put the call back into call back chain ( and append newMovieRate )
        hTempCallBackInfo = AddNewCallBackInfo( pWindow,
                                                                                        theNewCallBack,
                                                                                        (Ptr)&newMovieRate, sizeof ( long ),
                                                                                        triggerTimeFwd,
                                                                                        theCallBackOffset,
                                                                                        (**hDocMovieInfo).moviesTimeScale  );

// Attach the call back to the movie's time structures
        theErr = CallMeWhen ( theNewCallBack,
                                                        gAlterRateUpp,
                                                        (long)hTempCallBackInfo,
                                                        (**hTempCallBackInfo).param1,
                                                        (**hTempCallBackInfo).param2,
                                                        (**hTempCallBackInfo).param3 );
        if (theErr)
            ReportError( "\pError !! CallMeWhen", theErr );
        else
        {

// ---  Second call back - slow playback rate to 1/2 normal ----

// Work out length of delay before callbacks start
            if (delayBeforeChange == kOneThird)
                theCallBackOffset = theMovieLen*0.6666;
            else
                theCallBackOffset = (2 * delayBeforeChange) * (**hDocMovieInfo).moviesTimeScale;

// Create a new call back
            theNewCallBack = NewCallBack((**hDocMovieInfo).moviesTimeBase,callBackAtTime);

            newMovieRate = 32768;        // speed up rate to 1/2 normal

// Put the call back into call back chain ( and append newMovieRate )
            hTempCallBackInfo = AddNewCallBackInfo( pWindow,
                                                                                            theNewCallBack,
                                                                                            (Ptr)&newMovieRate, sizeof ( long ),
                                                                                            triggerTimeFwd,
                                                                                            theCallBackOffset,
                                                                                            (**hDocMovieInfo).moviesTimeScale  );

// Attach the call back to the movie's time structures
            theErr = CallMeWhen ( theNewCallBack,
                                                        gAlterRateUpp,
                                                        (long)hTempCallBackInfo,
                                                        (**hTempCallBackInfo).param1,
                                                        (**hTempCallBackInfo).param2,
                                                        (**hTempCallBackInfo).param3 );
            if (theErr)
                ReportError( "\pError !! CallMeWhen", theErr );
        }
    }
    return ( theErr );
}

//----------------------------------------------
//  SetupLoop
//
// Set up a loop in the movie.
// - It uses call backs, to change the position of
//   the movie "loopWhen" seconds into it and moves it
//   to "loopTo" seconds
//----------------------------------------------

OSErr SetupLoop ( WindowPtr pWindow,
                                    short    loopWhen,
                                    short    loopTo  )
{
    OSErr  theErr = noErr;
    DocMovieInfoHndl hDocMovieInfo; // Info about the windows movie
    long                 callBackWhen;  // When we want to start loop
    CallBackInfoHdl  hTempCallBackInfo; // Call back information
    QTCallBack             tempCallBack;  // Call Back
    TimeValue        newTimeValue;  // Where we want to loop to

    hDocMovieInfo = (DocMovieInfoHndl)GetWRefCon (pWindow);

// Calculate when the movie should 'jump'
    callBackWhen = loopWhen*(**hDocMovieInfo).moviesTimeScale;

// Creates a call back
    tempCallBack = NewCallBack((**hDocMovieInfo).moviesTimeBase, callBackAtTime);

// Set up where it's going to loop to
    newTimeValue = loopTo * (**hDocMovieInfo).moviesTimeScale;

// Add the call back to the call back list
    hTempCallBackInfo = AddNewCallBackInfo( pWindow,
                                                                                    tempCallBack,
                                                                                    (Ptr) &newTimeValue, sizeof ( TimeValue ),
                                                                                    triggerTimeFwd,
                                                                                    callBackWhen,
                                                                                    (**hDocMovieInfo).moviesTimeScale  );

// Attach the call back to the movie's time structures
    theErr = CallMeWhen( tempCallBack,
                                             gAlterMasterOffsetUpp, (long)hTempCallBackInfo,
                                            (**hTempCallBackInfo).param1,
                                            (**hTempCallBackInfo).param2,
                                            (**hTempCallBackInfo).param3 );

    return ( theErr );
}

//----------------------------------------------
// SetupSlaveMovie
//
// This sets up the slaved movie
// - "slaveAheadBy" sets the duration that the
//   slave  will lead the master (in seconds)
// - "slaveDelayStart" sets the duration that the
//   slave start will be delayed after the master starts
// - If both values are set the same, the slave will start
//   n seconds behind the master and run in sync
//----------------------------------------------


OSErr SetupSlaveMovie ( WindowPtr pMasterWindow,
                                                WindowPtr pSlaveWindow,
                                                short     slaveAheadBy,
                                                short     slaveDelayStart )
{
    OSErr                     theErr = noErr;
    DocMovieInfoHndl hDocMasterInfo;  // masters info
    DocMovieInfoHndl hDocSlaveInfo;   // slaves info
    long             slaveTimeOffset; // difference between the two movies
    long                 slaveStartDelay; // when we've got to start the slave
    CallBackInfoHdl  hTempCallBackInfo; // Call back information
    QTCallBack             tempCallBack;    // call back
    Movie            movieToStart;    // Put into the call back
    TimeValue               theMovieLen;     // Length of the movie

// Get the info about the two movies
    hDocMasterInfo = (DocMovieInfoHndl)GetWRefCon (pMasterWindow);
    hDocSlaveInfo  = (DocMovieInfoHndl)GetWRefCon (pSlaveWindow);

// Attach the slave window onto the master
    (**hDocMasterInfo).pSlaveWind = pSlaveWindow;

// Set the master movies time base value
    SetTimeBaseValue((**hDocMasterInfo).moviesTimeBase,0,(**hDocMasterInfo).moviesTimeScale);

// slave second movie to first
    SetMovieMasterTimeBase( (**hDocSlaveInfo).actualMovie,
                                                    (**hDocMasterInfo).moviesTimeBase,
                                                    nil );

// --- Setup the slave so it will lead the master ---
    if (slaveAheadBy != kInSync)
    {
// Calculate how big the offset should be
        if (slaveAheadBy == kOneThird)
        {
    // get the movie's length
            theMovieLen  = GetMovieDuration((**hDocSlaveInfo).actualMovie);
            slaveTimeOffset  = theMovieLen*0.3333;
        }
        else
            slaveTimeOffset  = slaveAheadBy*(**hDocMasterInfo).moviesTimeScale;

// Set the slaves time base offset
        SetTimeBaseValue( (**hDocSlaveInfo).moviesTimeBase,
                                            slaveTimeOffset,
                                            (**hDocSlaveInfo).moviesTimeScale);
        theErr = GetAndReportError( "\pError !! - Offsetting timebase" );
    }

// --- Put in the call back to start the slave movie (delayed if requested )--

// Set up slaveStartDelay
    if (slaveDelayStart == kInSync)
        slaveStartDelay = 0;
    else
        if (slaveDelayStart == kOneThird)
        {
    // get the movie's length
            theMovieLen  = GetMovieDuration((**hDocMasterInfo).actualMovie);
            slaveStartDelay = theMovieLen*0.3333;
        }
        else
            slaveStartDelay = slaveDelayStart * (**hDocMasterInfo).moviesTimeScale;

// Create a new call back
    tempCallBack = NewCallBack((**hDocMasterInfo).moviesTimeBase,callBackAtTime);

// Link the call back into the chain
    movieToStart = (**hDocSlaveInfo).actualMovie;
    hTempCallBackInfo = AddNewCallBackInfo( pMasterWindow,
                                                                                    tempCallBack,
                                                                                    (Ptr) &movieToStart, sizeof(Movie),
                                                                                    triggerTimeFwd,
                                                                                    slaveStartDelay,
                                                                                    (**hDocMasterInfo).moviesTimeScale  );

// Attach the call back to the movie's time structures
    theErr = CallMeWhen ( tempCallBack, gStartMovieCBUpp,
                                                (long)hTempCallBackInfo,
                                                (**hTempCallBackInfo).param1,
                                                (**hTempCallBackInfo).param2,
                                                (**hTempCallBackInfo).param3 );

    ReportError( "\pError!! - Creating movie start call back", theErr );

    return ( theErr );
}


//----------------------------------------------
// StartMovieWindow
//
// Start a movie in pWindow
//----------------------------------------------
OSErr StartMovieWindow( WindowPtr pWindow,
                                                Boolean   fromBegining  )
{
    DocMovieInfoHndl hDocMovieInfo;

    if (pWindow)
    {
        hDocMovieInfo = (DocMovieInfoHndl)GetWRefCon (pWindow);

// Set up the movie and start it
        if (fromBegining)
            GoToBeginningOfMovie((**hDocMovieInfo).actualMovie);

        SetMovieActive((**hDocMovieInfo).actualMovie,true);
        StartMovie((**hDocMovieInfo).actualMovie);
    }
    return( noErr );
}