zc030x_jpeg.c

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   u16 i,j;
   u16 i2; u16 j2;
   s16 cb; s16 cr;
   u16 xj;
   u16 yi;
   s16 r; s16 g; s16 b;
   
    // This is offset to place the decoded picture
    u8 x0 = 0;
    u8 y0 = 0;

    QTables = 0;     // Initialize some checkpoint variables
    ACTables = 0;
    DCTables = 0;

    findex = 0;

    if (JPGGetByte(jpgdata) == 0xff)
    {
      if (JPGGetByte(jpgdata) == 0xd8)
         exit = 0;
    }

    // Exit if not a JPEG file
    if (exit)
      return(0);

    //THOMMY:
    //get Width and Height from Jpeg header instead of relying on global variables.
    //this will prevent crashes if the variables FrameWidth and FrameHeight are set up inproperly.
    //this should allow me to test what happens if i set up framewidth and frameheigt to 640x480
    
    wWidth = ((int)jpgdata[12]<<8) | (int)jpgdata[13];
    height = ((int)jpgdata[14]<<8) | (int)jpgdata[15];

    if (height < wHeight)
	    wHeight = height;

    while (!exit)
    {
      if (JPGGetByte(jpgdata) == 0xff)
         {
         switch (JPGGetByte(jpgdata))
            {
            case 0x00: //not important
               break;
            case 0xc0: //SOF0
                PDEBUG(3,"Found start of frame 0");
                JPGGetImageAttr(jpgdata);
                break;
            case 0xc1: //SOF1
                PDEBUG(3,"Found start of frame 1");
                JPGGetImageAttr(jpgdata);
                break;
            case 0xc4: //DHT
                PDEBUG(3,"Found huffman tables (A:%d,D:%d)", ACTables, DCTables );
                if ((ACTables < 2) || (DCTables < 2))
                  JPGGetHuffTables(jpgdata);
                PDEBUG(3,"NbAC : %d, NbDC : %d", ACTables, DCTables);
                break;
            case 0xc9: //SOF9
                break;
            case 0xd9: //EOI
                PDEBUG(3,"Found end of image");
                exit = 1;
                break;
            case 0xda: //SOS
                PDEBUG(3,"Found start of scan");
                JPGGetSOS(jpgdata);
                if ( ((DCTables == 2) &&
                     (ACTables == 2) &&
                     (QTables == 2)) ||
                     (Image.NumComp == 1) )
                {
                    EOI = 0;
                    exit = 1;        // Go on to secondary control loop
                } else
                {
                    PDEBUG(3,"Not enough tables");
                }
                break;
            case 0xdb: //DQT
                PDEBUG(3,"Found quantification tables");
                if (QTables < 2)
                  JPGGetQuantTables(jpgdata);
                break;
            case 0xdd: //DRI
                PDEBUG(3,"Found restart interval");
                (void) JPGGetWord(jpgdata);        // Length of segment
                Restart = JPGGetWord(jpgdata);
                PDEBUG(3,"Restart read : %d", Restart);
                break;
            case 0xe0: //APP0
                PDEBUG(3,"Found application specific");
                (void) JPGGetWord(jpgdata);        // Length of segment
                findex += 5;
                (void) JPGGetByte(jpgdata);        // Major revision
                (void) JPGGetByte(jpgdata);        // Minor revision
                (void) JPGGetByte(jpgdata);        // Density definition
                (void) JPGGetByte(jpgdata);        // X density
                (void) JPGGetByte(jpgdata);        // Y density
                (void) JPGGetByte(jpgdata);        // Thumbnail width
                (void) JPGGetByte(jpgdata);        // Thumbnail height
                break;
            case 0xfe: //COM
// Modified by Cyril
// In Zc0302 modules, comment block is just before the real data
// So we just have to consider this as an header (need to specify value here)
// Modified by Cyril 26/9/04 - Forgot to think that JPGGetWord also advance findex
// Remark : Should read the picture size here, directly from the comment block.
// But for that, it would be better to be able to send the correct init sequence first. 
                findex += JPGGetWord(jpgdata) - 2;        // Length of segment;
                // Set to 1 for GreyScale pictures
                Image.NumComp = bGrey ? 1 : 3;
                // This is because this stream is in 4:2:2 format (ie YYUV YYUV etc)
                Image.SamplesY = 2; 
                Image.Cols     = wWidth;
                Image.Rows     = wHeight;
            
                Image.HuffACTableY = 0;
                Image.HuffDCTableY = 0;
                Image.HuffACTableCbCr = 1;
                Image.HuffDCTableCbCr = 1;
            
                EOI = 0;
                exit = 1;
            
               break;
            }
         }
    }

    XPos = 0;
    YPos = 0;                            // Initialize active variables
    dcY = 0; dcCb = 0; dcCr = 0;
    xindex = 0; yindex = 0; mcu = 0;
    r = 0; g = 0; b = 0;
    mcu = 0;
    
    
    curBits = 128;                // Start with the seventh bit
    curByte = JPGGetByte(jpgdata);       // Of the first byte
    
    switch (Image.NumComp)        // How many components does the image have?
    {
    case 3:                     // 3 components (Y-Cb-Cr)
    {
        PDEBUG(3,"The sampling ratio is : %d", Image.SamplesY);
        switch (Image.SamplesY)   // What's the sampling ratio of Y to CbCr?
        {
        case 2:           // 2 pixels to 1
        do
        {
            JPGGetBlock (YVector1, Image.HuffDCTableY,    Image.HuffACTableY,    Image.QuantTableY,    &dcY, jpgdata);
            JPGGetBlock (YVector2, Image.HuffDCTableY,    Image.HuffACTableY,    Image.QuantTableY,    &dcY, jpgdata);
            JPGGetBlock (CbVector, Image.HuffDCTableCbCr, Image.HuffACTableCbCr, Image.QuantTableCbCr, &dcCb, jpgdata);
            JPGGetBlock (CrVector, Image.HuffDCTableCbCr, Image.HuffACTableCbCr, Image.QuantTableCbCr, &dcCr, jpgdata);
            // YCbCr vectors have been obtained
//            PDEBUG(3,"Got the 4 blocks (now at %d,%d)", xindex, yindex);
            mcu++;
            
            if (EOI)
            {
                PDEBUG(3,"Error appeared with this picture");
                return 0;
            }
            
	    //modified by tommy
	    //for YUV colorspaces
            for (i=0; i<8; i++)       // Draw left 8x8 pixels
                for (j=0; j<8; j++)
                {
                    y = YVector1[i][j];
                    i2 = i >> 1;
                    j2 = j >> 1;
                    cb = CbVector[i2][j2];
                    cr = CrVector[i2][j2];
                    JPGToBGR (y, cb, cr, &b, &g, &r);
                    xj = xindex + j;
                    yi = yindex + i;
                    if ((xj < Image.Cols) && (yi < Image.Rows))
                        gfxPixelRGB32 (xj + x0, yi + y0, BGR(b, g, r), vram, wWidth, wHeight);
                }
        
            for (i=0; i<8; i++)       // Draw right 8x8 pixels
                for (j=8; j<16; j++)
                {
                    y = YVector2[i][j - 8];
                    i2 = i >> 1;
                    j2 = j >> 1;
                    cb = CbVector[i2][j2];
                    cr = CrVector[i2][j2];
                    JPGToBGR (y, cb, cr, &b, &g, &r);
                    xj = xindex + j;
                    yi = yindex + i;
                    if ((xj < Image.Cols) && (yi < Image.Rows))
                        gfxPixelRGB32 (xj + x0, yi + y0, BGR(b, g, r), vram, wWidth, wHeight);
                }

            xindex += 16;
                
                
            if (Restart && mcu == Restart)
            {
                // eject restart marker now
                u8 marker0 = JPGGetByte(jpgdata);
                u8 marker1 = JPGGetByte(jpgdata);
                
                if (marker0 != 0xFF || (marker1 < 0xD0 && marker1 > 0xD7))
                {
                        // A restart marker should be here, but not found
                        PDEBUG(3,"Restart should be here, but not found, arounding byte are :");
                        PDEBUG(3,"%02X%02X%02X%02X%02X%02X%02X%02X %02X%02X%02X%02X%02X%02X%02X%02X", 
                        jpgdata[findex - 10], jpgdata[findex - 9], jpgdata[findex - 8], jpgdata[findex - 6],
                        jpgdata[findex -  5], jpgdata[findex - 4], jpgdata[findex - 3], jpgdata[findex - 2],
                        jpgdata[findex -  1], jpgdata[findex    ], jpgdata[findex + 1], jpgdata[findex + 2],
                        jpgdata[findex +  3], jpgdata[findex + 4], jpgdata[findex + 5], jpgdata[findex + 6]);
                    
                        PDEBUG(3,"Resync the stream now");
                        // Look in the +/- 8 bytes to find restart marker
                        for (j = 0; j < 16; j++)
                        {
                            if (jpgdata[findex - 10 + j] == 0xFF && (jpgdata[findex - 9 + j] >= 0xD0 && jpgdata[findex - 9 + j] <= 0xD7 ))
                            {
                                // Found restart marker, sync the stream now
                                findex -=  (10 - j);
                                marker0 = JPGGetByte(jpgdata); 
                                marker1 = JPGGetByte(jpgdata);
                                PDEBUG(3,"Marker found : %02X, %02X", marker0, marker1);
                                break;
                            }
                        }
                        
                        // No restart marker found, so stop decoding
                        if (j == 16)
                            return(0);
                    
                }                    

                // Feed again the decoder
                curByte = JPGGetByte(jpgdata); PDEBUG(3,"%02X", curByte);
                curBits = 128;
                
                dcY = 0; dcCb = 0; dcCr = 0; mcu = 0;  //Reset the DC value
            }
        
            if (xindex >= Image.Cols)
            {
                xindex = 0; yindex += 8;
                //mcu = 0;
            }
        }
        while (yindex < Image.Rows);
        break;
      }
        
    }
    case 1:
        do
        {
            JPGGetBlock (YVector1, Image.HuffDCTableY, Image.HuffACTableY, Image.QuantTableY, &dcY, jpgdata);
        
            for (i=0; i<8; i++)           // Draw 8x8 pixels
                for (j=0; j<8; j++)
                {
                    y = YVector1[i][j];
                    if (y < 0) y = 0;
                    if (y > 255) y = 255;
                    xj = xindex + j;
                    yi = yindex + i;
                    if ((xj < Image.Cols) && (yi < Image.Rows))
                       gfxPixelRGB32 (xj + x0, yi + y0, y, y, y, vram, wWidth, wHeight);
             }
        
            xindex += 8;
            if (xindex >= Image.Cols)
            {
                xindex = 0; yindex += 8; mcu = 1;
            }
        
            if ((mcu == 1) && (Restart != 0))   // execute the restart interval
            {
                curByte = JPGGetByte(jpgdata); curByte = JPGGetByte(jpgdata); curByte = JPGGetByte(jpgdata);
                curBits = 128;
                dcY = 0; mcu = 0;
           }
        }
        while (yindex < Image.Rows);
    break;
    }

    return(1);
}

/* Decode a picture */
u32 gfxJpegRGB24 (u8 bGrey, u16 wWidth, u16 wHeight, u8 *vram, u8 * jpgdata, int format)
{
   u8 exit = 1;
//   u16 u,v;
//   s16 x;
   s16 y;
//   float t;
   u16 Restart = 0;
   u16 XPos; u16 YPos;
   s16 dcY; s16 dcCb; s16 dcCr;
   u16 xindex; u16 yindex;
   u16 mcu;
   s16 YVector1[8][8];              // 4 vectors for Y attribute
   s16 YVector2[8][8];              // (not all may be needed)
   s16 CbVector[8][8];              // 1 vector for Cb attribute
   s16 CrVector[8][8];              // 1 vector for Cr attribute
   s16 height;

   u16 i,j;
   u16 i2; u16 j2;
   s16 cb; s16 cr;
   u16 xj;
   u16 yi;
   s16 r; s16 g; s16 b;
   
    // This is offset to place the decoded picture
    u8 x0 = 0;
    u8 y0 = 0;

    QTables = 0;     // Initialize some checkpoint variables
    ACTables = 0;
    DCTables = 0;

    findex = 0;

    if (JPGGetByte(jpgdata) == 0xff)
    {
      if (JPGGetByte(jpgdata) == 0xd8)
         exit = 0;
    }

    // Exit if not a JPEG file
    if (exit)
      return(0);

    //THOMMY:
    //get Width and Height from Jpeg header instead of relying on global variables.
    //this will prevent crashes if the variables FrameWidth and FrameHeight are set up inproperly.
    //this should allow me to test what happens if i set up framewidth and frameheigt to 640x480
    
    wWidth = ((int)jpgdata[12]<<8) | (int)jpgdata[13];
    height = ((int)jpgdata[14]<<8) | (int)jpgdata[15];

    if (height < wHeight)
	    wHeight = height;

    while (!exit)
    {
      if (JPGGetByte(jpgdata) == 0xff)
         {
         switch (JPGGetByte(jpgdata))
            {
            case 0x00: //not important
               break;
            case 0xc0: //SOF0
                PDEBUG(3,"Found start of frame 0");
                JPGGetImageAttr(jpgdata);
                break;
            case 0xc1: //SOF1
                PDEBUG(3,"Found start of frame 1");
                JPGGetImageAttr(jpgdata);
                break;
            case 0xc4: //DHT
                PDEBUG(3,"Found huffman tables (A:%d,D:%d)", ACTables, DCTables );
                if ((ACTables < 2) || (DCTables < 2))
                  JPGGetHuffTables(jpgdata);
                PDEBUG(3,"NbAC : %d, NbDC : %d", ACTables, DCTables);
                break;
            case 0xc9: //SOF9
                break;
            case 0xd9: //EOI
                PDEBUG(3,"Found end of image");
                exit = 1;
                break;
            case 0xda: //SOS
                PDEBUG(3,"Found start of scan");
                JPGGetSOS(jpgdata);
                if ( ((DCTables == 2) &&
                     (ACTables == 2) &&
                     (QTables == 2)) ||
                     (Image.NumComp == 1) )
                {
                    EOI = 0;
                    exit = 1;        // Go on to secondary control loop
                } else
                {
                    PDEBUG(3,"Not enough tables");