//////////

//

//  File:       QTReadWriteJPEG.h

//

//  Contains:   Sample code for compressing and decompressing JPEG images.

//

//  Written by: Michael Marinkovich and Guillermo Ortiz

//  Revised by: Tim Monroe

//              Based heavily on the existing "JPEG Sample" code.

//

//  Copyright:  © 1996-1998 by Apple Computer, Inc., all rights reserved.

//

//  Change History (most recent first):

//

//     <1>      04/27/98    rtm     first file

//     

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//

// header files

//

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#include <FixMath.h>

#include <ImageCompression.h>

#include <Movies.h>

#include <QuickTimeComponents.h>

#include <StandardFile.h>

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//

// constants

//

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#define kImageFileCreator       FOUR_CHAR_CODE('ogle')

#define kBufferSize             codecMinimumDataSize        // data unload buffer size

#define kSaveImagePrompt        "Save compressed image as:"

#define kSaveImageFileName      "Untitled.jpg"

#define kWindowTitle            "Photo - JPEG"

// JFIF (JPEG) markers

enum {

    kSOFMarker                  = 0xC0,                     // start Of Frame N

    kSOFMarker2                 = 0xC2,

    kDHTMarker                  = 0xC4,                     // DHT Marker

    kDACMarker                  = 0xCC,                     // DAC

    kRSTOMarker                 = 0xD0,                     // RSTO marker

    kSOIMarker                  = 0xD8,                     // image start marker

    kEOIMarker                  = 0xD9,                     // image end marker

    kSOSMarker                  = 0xDA,                     // SOS marker

    kDQTMarker                  = 0xDB,                     // DQT marker

    kAPPOMarker                 = 0xE0,                     // APPO marker

    kCommentMarker              = 0xFE,                     // comment marker

    kStartMarker                = 0xFF                      // marker loacted after this byte

};

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//

// data types

//

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// a record to hold info about the JPEG data while we're loading it from disk

struct DLDataRec

{   

    long                        fRefNum;                    // ref number of current file

    long                        fFileLength;            

    Ptr                         fOrigPtr;                   // address of start of buffer

    Ptr                         fEndPtr;                    // address of end of buffer

};

typedef struct DLDataRec DLDataRec;

typedef DLDataRec *DLDataPtr, **DLDataHnd;

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//

// function prototypes

//

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void                            QTJPEG_PromptUserForJPEGFileAndDisplay (void);

OSErr                           QTJPEG_ReadJPEG (FSSpec theFSSpec, CGrafPtr *theGWorld);

OSErr                           QTJPEG_ConvertJPEG (Handle image, CGrafPtr *newWorld);

OSErr                           QTJPEG_ReadJPEGHeader (short theRefNum, ImageDescriptionHandle theDesc, Rect *theRect);

UInt8                           QTJPEG_FindNextMarker (long theRefNum);

OSErr                           QTJPEG_HandleAPPOMarker (UInt8 theMarker, long theRefNum, ImageDescriptionHandle theDesc, Boolean *readingExtension);

OSErr                           QTJPEG_HandleSOFMarker (long theRefNum, ImageDescriptionHandle theDesc, Boolean readingExtension);

void                            QTJPEG_HandleSOSMarker (long theRefNum);

UInt8                           QTJPEG_ReadByte (short theRefNum);

UInt16                          QTJPEG_ReadWord (short theRefNum);

void                            QTJPEG_SkipLength (long theRefNum);

OSErr                           QTJPEG_NewJPEGWorld (GWorldPtr *theWorld, short theDepth, Rect theRect);

OSErr                           QTJPEG_SaveJPEG (GWorldPtr theWorld);

PASCAL_RTN OSErr                QTJPEG_DataUnloadProc (Ptr theData, long theBytesNeeded, long theRefCon);

PASCAL_RTN OSErr                QTJPEG_DataLoadingProc (Ptr *theData, long theBytesNeeded, long theRefCon);