winamp/Src/libvpShared/corelibs/cdxv/vputil/generic/idctpart.c

/****************************************************************************
*
*   Module Title :     idctpart.c
*
*   Description  :     IDCT with multiple versions based on # of non 0 coeffs
*
****************************************************************************/

/****************************************************************************
*  Header Files
****************************************************************************/

#include "dct.h"
#include "string.h"

/****************************************************************************
*  Macros
****************************************************************************/
#define int32 int
#define int16 short
#define IdctAdjustBeforeShift 8

#define xC1S7 64277
#define xC2S6 60547
#define xC3S5 54491
#define xC4S4 46341
#define xC5S3 36410
#define xC6S2 25080
#define xC7S1 12785

/****************************************************************************
*  Module statics
****************************************************************************/
static const UINT32 dequant_index[64] = 
{	
    0,  1,  8,  16,  9,  2,  3, 10,
	17, 24, 32, 25, 18, 11,  4,  5,
    12, 19, 26, 33, 40, 48, 41, 34,
    27, 20, 13,  6,  7, 14, 21, 28,
    35, 42, 49, 56, 57, 50, 43, 36, 
    29, 22, 15, 23, 30, 37, 44, 51,
    58, 59, 52, 45, 38, 31, 39, 46,
    53, 60, 61, 54, 47, 55, 62, 63
};

#if 0   // AWG CODE NO LONGER USED IN CODEBASE.
/*	Cos and Sin constant multipliers used during DCT and IDCT */
const double C1S7 = (double)0.9807852804032;
const double C2S6 = (double)0.9238795325113;
const double C3S5 = (double)0.8314696123025;
const double C4S4 = (double)0.7071067811865;
const double C5S3 = (double)0.5555702330196;
const double C6S2 = (double)0.3826834323651;
const double C7S1 = (double)0.1950903220161;

/****************************************************************************
*  Exports
****************************************************************************/

// DCT lookup tables
INT32 * C4S4_TablePtr;
INT32 C4S4_Table[(COEFF_MAX * 4) + 1];

INT32 * C6S2_TablePtr;
INT32 C6S2_Table[(COEFF_MAX * 2) + 1];

INT32 * C2S6_TablePtr;
INT32 C2S6_Table[(COEFF_MAX * 2) + 1];

INT32 * C1S7_TablePtr;
INT32 C1S7_Table[(COEFF_MAX * 2) + 1];

INT32 * C7S1_TablePtr;
INT32 C7S1_Table[(COEFF_MAX * 2) + 1];

INT32 * C3S5_TablePtr;
INT32 C3S5_Table[(COEFF_MAX * 2) + 1];

INT32 * C5S3_TablePtr;
INT32 C5S3_Table[(COEFF_MAX * 2) + 1];

/****************************************************************************
 * 
 *  ROUTINE       :     InitDctTables
 *
 *  INPUTS        :     None.
 *
 *  OUTPUTS       :     None.
 *
 *  RETURNS       :     void
 *
 *  FUNCTION      :     Initialises lookup tables used in IDCT.
 *
 *  SPECIAL NOTES :     NO LONGER USED IN CODEBASE. 
 *
 ****************************************************************************/
void InitDctTables ( void )
{
    INT32 i;

    C4S4_TablePtr = &C4S4_Table[COEFF_MAX*2];
    for( i = -(2 * COEFF_MAX); i < (2 * COEFF_MAX); i++ )
    {
        if ( i < 0 )
            C4S4_TablePtr[i] = (INT32)((i * C4S4) - 0.5);
        else
            C4S4_TablePtr[i] = (INT32)((i * C4S4) + 0.5);
    }

    C6S2_TablePtr = &C6S2_Table[COEFF_MAX];
    for( i = -COEFF_MAX ; i < COEFF_MAX; i++ )
    {
        if ( i < 0 )
            C6S2_TablePtr[i] = (INT32)((i * C6S2) - 0.5);
        else
            C6S2_TablePtr[i] = (INT32)((i * C6S2) + 0.5);
    }

    C2S6_TablePtr = &C2S6_Table[COEFF_MAX];
    for( i = -COEFF_MAX ; i < COEFF_MAX; i++ )
    {
        if ( i < 0 )
            C2S6_TablePtr[i] = (INT32)((i * C2S6) - 0.5);
        else
            C2S6_TablePtr[i] = (INT32)((i * C2S6) + 0.5);
    }

    C1S7_TablePtr = &C1S7_Table[COEFF_MAX];
    for( i = -COEFF_MAX ; i < COEFF_MAX; i++ )
    {
        if ( i < 0 )
            C1S7_TablePtr[i] = (INT32)((i * C1S7) - 0.5);
        else
            C1S7_TablePtr[i] = (INT32)((i * C1S7) + 0.5);
    }

    C7S1_TablePtr = &C7S1_Table[COEFF_MAX];
    for( i = -COEFF_MAX ; i < COEFF_MAX; i++ )
    {
        if ( i < 0 )
            C7S1_TablePtr[i] = (INT32)((i * C7S1) - 0.5);
        else
            C7S1_TablePtr[i] = (INT32)((i * C7S1) + 0.5);
    }

    C3S5_TablePtr = &C3S5_Table[COEFF_MAX];
    for( i = -COEFF_MAX ; i < COEFF_MAX; i++ )
    {
        if ( i < 0 )
            C3S5_TablePtr[i] = (INT32)((i * C3S5) - 0.5);
        else
            C3S5_TablePtr[i] = (INT32)((i * C3S5) + 0.5);
    }

    C5S3_TablePtr = &C5S3_Table[COEFF_MAX];
    for( i = -COEFF_MAX ; i < COEFF_MAX; i++ )
    {
        if ( i < 0 )
            C5S3_TablePtr[i] = (INT32)((i * C5S3) - 0.5);
        else
            C5S3_TablePtr[i] = (INT32)((i * C5S3) + 0.5);
    }
}
#endif

/****************************************************************************
 * 
 *  ROUTINE       : dequant_slow
 *
 *  INPUTS        : INT16 *dequant_coeffs : Pointer to dequantization step sizes.
 *                  INT16 *quantized_list : Pointer to quantized DCT coeffs
 *                                          (in zig-zag order).
 *
 *  OUTPUTS       : INT32 *DCT_block      : Pointer to 8x8 de-quantized block
 *                                          (in 2-D raster order).
 *
 *  RETURNS       : void
 *
 *  FUNCTION      : De-quantizes an 8x8 block of quantized DCT coeffs.
 *
 *  SPECIAL NOTES : Uses dequant_index to invert zig-zag ordering. 
 *
 ****************************************************************************/
void dequant_slow ( INT16 *dequant_coeffs, INT16 *quantized_list, INT32 *DCT_block )
{
    // Loop fully expanded for maximum speed
    DCT_block[dequant_index[0]]  = quantized_list[0]  * dequant_coeffs[0];
    DCT_block[dequant_index[1]]  = quantized_list[1]  * dequant_coeffs[1];
    DCT_block[dequant_index[2]]  = quantized_list[2]  * dequant_coeffs[2];
    DCT_block[dequant_index[3]]  = quantized_list[3]  * dequant_coeffs[3];
    DCT_block[dequant_index[4]]  = quantized_list[4]  * dequant_coeffs[4];
    DCT_block[dequant_index[5]]  = quantized_list[5]  * dequant_coeffs[5];
    DCT_block[dequant_index[6]]  = quantized_list[6]  * dequant_coeffs[6];
    DCT_block[dequant_index[7]]  = quantized_list[7]  * dequant_coeffs[7];
    DCT_block[dequant_index[8]]  = quantized_list[8]  * dequant_coeffs[8];
    DCT_block[dequant_index[9]]  = quantized_list[9]  * dequant_coeffs[9];
    DCT_block[dequant_index[10]] = quantized_list[10] * dequant_coeffs[10];
    DCT_block[dequant_index[11]] = quantized_list[11] * dequant_coeffs[11];
    DCT_block[dequant_index[12]] = quantized_list[12] * dequant_coeffs[12];
    DCT_block[dequant_index[13]] = quantized_list[13] * dequant_coeffs[13];
    DCT_block[dequant_index[14]] = quantized_list[14] * dequant_coeffs[14];
    DCT_block[dequant_index[15]] = quantized_list[15] * dequant_coeffs[15];
    DCT_block[dequant_index[16]] = quantized_list[16] * dequant_coeffs[16];
    DCT_block[dequant_index[17]] = quantized_list[17] * dequant_coeffs[17];
    DCT_block[dequant_index[18]] = quantized_list[18] * dequant_coeffs[18];
    DCT_block[dequant_index[19]] = quantized_list[19] * dequant_coeffs[19];
    DCT_block[dequant_index[20]] = quantized_list[20] * dequant_coeffs[20];
    DCT_block[dequant_index[21]] = quantized_list[21] * dequant_coeffs[21];
    DCT_block[dequant_index[22]] = quantized_list[22] * dequant_coeffs[22];
    DCT_block[dequant_index[23]] = quantized_list[23] * dequant_coeffs[23];
    DCT_block[dequant_index[24]] = quantized_list[24] * dequant_coeffs[24];
    DCT_block[dequant_index[25]] = quantized_list[25] * dequant_coeffs[25];
    DCT_block[dequant_index[26]] = quantized_list[26] * dequant_coeffs[26];
    DCT_block[dequant_index[27]] = quantized_list[27] * dequant_coeffs[27];
    DCT_block[dequant_index[28]] = quantized_list[28] * dequant_coeffs[28];
    DCT_block[dequant_index[29]] = quantized_list[29] * dequant_coeffs[29];
    DCT_block[dequant_index[30]] = quantized_list[30] * dequant_coeffs[30];
    DCT_block[dequant_index[31]] = quantized_list[31] * dequant_coeffs[31];
    DCT_block[dequant_index[32]] = quantized_list[32] * dequant_coeffs[32];
    DCT_block[dequant_index[33]] = quantized_list[33] * dequant_coeffs[33];
    DCT_block[dequant_index[34]] = quantized_list[34] * dequant_coeffs[34];
    DCT_block[dequant_index[35]] = quantized_list[35] * dequant_coeffs[35];
    DCT_block[dequant_index[36]] = quantized_list[36] * dequant_coeffs[36];
    DCT_block[dequant_index[37]] = quantized_list[37] * dequant_coeffs[37];
    DCT_block[dequant_index[38]] = quantized_list[38] * dequant_coeffs[38];
    DCT_block[dequant_index[39]] = quantized_list[39] * dequant_coeffs[39];
    DCT_block[dequant_index[40]] = quantized_list[40] * dequant_coeffs[40];
    DCT_block[dequant_index[41]] = quantized_list[41] * dequant_coeffs[41];
    DCT_block[dequant_index[42]] = quantized_list[42] * dequant_coeffs[42];
    DCT_block[dequant_index[43]] = quantized_list[43] * dequant_coeffs[43];
    DCT_block[dequant_index[44]] = quantized_list[44] * dequant_coeffs[44];
    DCT_block[dequant_index[45]] = quantized_list[45] * dequant_coeffs[45];
    DCT_block[dequant_index[46]] = quantized_list[46] * dequant_coeffs[46];
    DCT_block[dequant_index[47]] = quantized_list[47] * dequant_coeffs[47];
    DCT_block[dequant_index[48]] = quantized_list[48] * dequant_coeffs[48];
    DCT_block[dequant_index[49]] = quantized_list[49] * dequant_coeffs[49];
    DCT_block[dequant_index[50]] = quantized_list[50] * dequant_coeffs[50];
    DCT_block[dequant_index[51]] = quantized_list[51] * dequant_coeffs[51];
    DCT_block[dequant_index[52]] = quantized_list[52] * dequant_coeffs[52];
    DCT_block[dequant_index[53]] = quantized_list[53] * dequant_coeffs[53];
    DCT_block[dequant_index[54]] = quantized_list[54] * dequant_coeffs[54];
    DCT_block[dequant_index[55]] = quantized_list[55] * dequant_coeffs[55];
    DCT_block[dequant_index[56]] = quantized_list[56] * dequant_coeffs[56];
    DCT_block[dequant_index[57]] = quantized_list[57] * dequant_coeffs[57];
    DCT_block[dequant_index[58]] = quantized_list[58] * dequant_coeffs[58];
    DCT_block[dequant_index[59]] = quantized_list[59] * dequant_coeffs[59];
    DCT_block[dequant_index[60]] = quantized_list[60] * dequant_coeffs[60];
    DCT_block[dequant_index[61]] = quantized_list[61] * dequant_coeffs[61];
    DCT_block[dequant_index[62]] = quantized_list[62] * dequant_coeffs[62];
    DCT_block[dequant_index[63]] = quantized_list[63] * dequant_coeffs[63];
}

/****************************************************************************
 * 
 *  ROUTINE       : IDctSlow
 *
 *  INPUTS        : int16 *InputData   : Pointer to 8x8 quantized DCT coefficients.
 *                  int16 *QuantMatrix : Pointer to 8x8 quantization matrix.
 *
 *  OUTPUTS       : int16 *OutputData  : Pointer to 8x8 block to hold output.
 *
 *  RETURNS       : void
 *
 *  FUNCTION      : Inverse quantizes and inverse DCT's input 8x8 block
 *                  to reproduce prediction error.
 *
 *  SPECIAL NOTES : None. 
 *
 ****************************************************************************/
void IDctSlow ( int16 *InputData, int16 *QuantMatrix, int16 *OutputData )
{
	int   loop;
	int32 t1, t2;
    int32 IntermediateData[64];
	int32 _A, _B, _C, _D, _Ad, _Bd, _Cd, _Dd, _E, _F, _G, _H;
	int32 _Ed, _Gd, _Add, _Bdd, _Fd, _Hd;
	
    int32 *ip = IntermediateData;
	int16 *op = OutputData;
	
	// dequantize the input 
	dequant_slow ( QuantMatrix, InputData, IntermediateData );

	// Inverse DCT on the rows now
	for ( loop=0; loop<8; loop++ )
	{
		// Check for non-zero values
		if ( ip[0] | ip[1] | ip[2] | ip[3] | ip[4] | ip[5] | ip[6] | ip[7] )
		{
			t1 = (int32)(xC1S7 * ip[1]);
            t2 = (int32)(xC7S1 * ip[7]);
            t1 >>= 16;
            t2 >>= 16;
			_A = t1 + t2;

			t1 = (int32)(xC7S1 * ip[1]);
			t2 = (int32)(xC1S7 * ip[7]);
            t1 >>= 16;
            t2 >>= 16;
			_B = t1 - t2;

			t1 = (int32)(xC3S5 * ip[3]);
			t2 = (int32)(xC5S3 * ip[5]);
            t1 >>= 16;
            t2 >>= 16;
			_C = t1 + t2;

			t1 = (int32)(xC3S5 * ip[5]);
			t2 = (int32)(xC5S3 * ip[3]);
            t1 >>= 16;
            t2 >>= 16;
			_D = t1 - t2;

			t1 = (int32)(xC4S4 * (_A - _C));
            t1 >>= 16;
			_Ad = t1;

			t1 = (int32)(xC4S4 * (_B - _D));
            t1 >>= 16;
			_Bd = t1;
			
			_Cd = _A + _C;
			_Dd = _B + _D;

			t1 = (int32)(xC4S4 * (ip[0] + ip[4]));
            t1 >>= 16;
			_E = t1;

			t1 = (int32)(xC4S4 * (ip[0] - ip[4]));
            t1 >>= 16;
			_F = t1;
			
			t1 = (int32)(xC2S6 * ip[2]);
			t2 = (int32)(xC6S2 * ip[6]);
            t1 >>= 16;
            t2 >>= 16;
			_G = t1 + t2;

			t1 = (int32)(xC6S2 * ip[2]);
			t2 = (int32)(xC2S6 * ip[6]);
            t1 >>= 16;
            t2 >>= 16;
			_H = t1 - t2;

			_Ed = _E - _G;
			_Gd = _E + _G;

			_Add = _F + _Ad;
			_Bdd = _Bd - _H;
			
			_Fd = _F - _Ad;
			_Hd = _Bd + _H;
	
			// Final sequence of operations over-write original inputs.
			ip[0] = (int16)((_Gd + _Cd )  >> 0);
			ip[7] = (int16)((_Gd - _Cd )  >> 0);

			ip[1] = (int16)((_Add + _Hd ) >> 0);
			ip[2] = (int16)((_Add - _Hd ) >> 0);

			ip[3] = (int16)((_Ed + _Dd )  >> 0);
			ip[4] = (int16)((_Ed - _Dd )  >> 0);

			ip[5] = (int16)((_Fd + _Bdd ) >> 0);
			ip[6] = (int16)((_Fd - _Bdd ) >> 0);
		}

		ip += 8;			/* next row */
	}

	ip = IntermediateData;

	for ( loop=0; loop<8; loop++ )
	{
		// Check for non-zero values (bitwise | faster than logical ||)
		if ( ip[0 * 8] | ip[1 * 8] | ip[2 * 8] | ip[3 * 8] |
			 ip[4 * 8] | ip[5 * 8] | ip[6 * 8] | ip[7 * 8] )
		{

			t1 = (int32)(xC1S7 * ip[1*8]);
            t2 = (int32)(xC7S1 * ip[7*8]);
            t1 >>= 16;
            t2 >>= 16;
			_A = t1 + t2;

			t1 = (int32)(xC7S1 * ip[1*8]);
			t2 = (int32)(xC1S7 * ip[7*8]);
            t1 >>= 16;
            t2 >>= 16;
			_B = t1 - t2;

			t1 = (int32)(xC3S5 * ip[3*8]);
			t2 = (int32)(xC5S3 * ip[5*8]);
            t1 >>= 16;
            t2 >>= 16;
			_C = t1 + t2;

			t1 = (int32)(xC3S5 * ip[5*8]);
			t2 = (int32)(xC5S3 * ip[3*8]);
            t1 >>= 16;
            t2 >>= 16;
			_D = t1 - t2;

			t1 = (int32)(xC4S4 * (_A - _C));
            t1 >>= 16;
			_Ad = t1;

			t1 = (int32)(xC4S4 * (_B - _D));
            t1 >>= 16;
			_Bd = t1;

			_Cd = _A + _C;
			_Dd = _B + _D;

			t1 = (int32)(xC4S4 * (ip[0*8] + ip[4*8]));
            t1 >>= 16;
			_E = t1;

			t1 = (int32)(xC4S4 * (ip[0*8] - ip[4*8]));
            t1 >>= 16;
			_F = t1;
			
			t1 = (int32)(xC2S6 * ip[2*8]);
			t2 = (int32)(xC6S2 * ip[6*8]);
            t1 >>= 16;
            t2 >>= 16;
			_G = t1 + t2;

			t1 = (int32)(xC6S2 * ip[2*8]);
			t2 = (int32)(xC2S6 * ip[6*8]);
            t1 >>= 16;
            t2 >>= 16;
			_H = t1 - t2;
			
			_Ed = _E - _G;
			_Gd = _E + _G;

			_Add = _F + _Ad;
			_Bdd = _Bd - _H;
			
			_Fd = _F - _Ad;
			_Hd = _Bd + _H;
	
			_Gd += IdctAdjustBeforeShift;
			_Add += IdctAdjustBeforeShift;
			_Ed += IdctAdjustBeforeShift;
			_Fd += IdctAdjustBeforeShift;

			// Final sequence of operations over-write original inputs.
			op[0*8] = (int16)((_Gd + _Cd )  >> 4);
			op[7*8] = (int16)((_Gd - _Cd )  >> 4);

			op[1*8] = (int16)((_Add + _Hd ) >> 4);
			op[2*8] = (int16)((_Add - _Hd ) >> 4);

			op[3*8] = (int16)((_Ed + _Dd )  >> 4);
			op[4*8] = (int16)((_Ed - _Dd )  >> 4);

			op[5*8] = (int16)((_Fd + _Bdd ) >> 4);
			op[6*8] = (int16)((_Fd - _Bdd ) >> 4);
		}
		else
		{
			op[0*8] = 0;
			op[7*8] = 0;
			op[1*8] = 0;
			op[2*8] = 0;
			op[3*8] = 0;
			op[4*8] = 0;
			op[5*8] = 0;
			op[6*8] = 0;
		}

		ip++;			// next column
        op++;
	}
}

/****************************************************************************
 * 
 *  ROUTINE       : dequant_slow10
 *
 *  INPUTS        : INT16 *dequant_coeffs : Pointer to dequantization step sizes.
 *                  INT16 *quantized_list : Pointer to quantized DCT coeffs
 *                                          (in zig-zag order).
 *
 *  OUTPUTS       : INT32 *DCT_block      : Pointer to 8x8 de-quantized block
 *                                          (in 2-D raster order).
 *
 *  RETURNS       : void
 *
 *  FUNCTION      : De-quantizes an 8x8 block of quantized DCT coeffs that
 *                  only has non-zero coefficients in the first 10, i.e.
 *                  only DC & AC1-9 are non-zero, AC10-63 __MUST_BE_ zero.
 *
 *  SPECIAL NOTES : Uses dequant_index to invert zig-zag ordering. 
 *
 ****************************************************************************/
void dequant_slow10 ( INT16 *dequant_coeffs, INT16 *quantized_list, INT32 *DCT_block )
{
	memset(DCT_block,0, 128);

	// Loop fully expanded for maximum speed
    DCT_block[dequant_index[0]]  = quantized_list[0]  * dequant_coeffs[0];
    DCT_block[dequant_index[1]]  = quantized_list[1]  * dequant_coeffs[1];
    DCT_block[dequant_index[2]]  = quantized_list[2]  * dequant_coeffs[2];
    DCT_block[dequant_index[3]]  = quantized_list[3]  * dequant_coeffs[3];
    DCT_block[dequant_index[4]]  = quantized_list[4]  * dequant_coeffs[4];
    DCT_block[dequant_index[5]]  = quantized_list[5]  * dequant_coeffs[5];
    DCT_block[dequant_index[6]]  = quantized_list[6]  * dequant_coeffs[6];
    DCT_block[dequant_index[7]]  = quantized_list[7]  * dequant_coeffs[7];
    DCT_block[dequant_index[8]]  = quantized_list[8]  * dequant_coeffs[8];
    DCT_block[dequant_index[9]]  = quantized_list[9]  * dequant_coeffs[9];
    DCT_block[dequant_index[10]] = quantized_list[10] * dequant_coeffs[10];

}

/****************************************************************************
 * 
 *  ROUTINE       : IDctSlow10
 *
 *  INPUTS        : int16 *InputData   : Pointer to 8x8 quantized DCT coefficients.
 *                  int16 *QuantMatrix : Pointer to 8x8 quantization matrix.
 *
 *  OUTPUTS       : int16 *OutputData  : Pointer to 8x8 block to hold output.
 *
 *  RETURNS       : void
 *
 *  FUNCTION      : Inverse quantizes and inverse DCT's input 8x8 block
 *                  with non-zero coeffs only in DC & the first 9 AC coeffs.
 *                  i.e. non-zeros ONLY in the following 10 positions:
 *                  
 *                          x  x  x  x  0  0  0  0
 *                          x  x  x  0  0  0  0  0
 *                          x  x  0  0  0  0  0  0
 *                          x  0  0  0  0  0  0  0
 *                          0  0  0  0  0  0  0  0
 *                          0  0  0  0  0  0  0  0
 *                          0  0  0  0  0  0  0  0
 *                          0  0  0  0  0  0  0  0
 *
 *  SPECIAL NOTES : Output data is in raster, not zig-zag, order.
 *
 ****************************************************************************/
void IDct10 ( int16 *InputData, int16 *QuantMatrix, int16 *OutputData )
{
	int   loop;
	int32 t1, t2;
	int32 IntermediateData[64];
	int32 _A, _B, _C, _D, _Ad, _Bd, _Cd, _Dd, _E, _F, _G, _H;
	int32 _Ed, _Gd, _Add, _Bdd, _Fd, _Hd;

    int32 *ip = IntermediateData;
	int16 *op = OutputData;
	
	// dequantize the input 
	dequant_slow10 ( QuantMatrix, InputData, IntermediateData );

	// Inverse DCT on the rows now
	for ( loop=0; loop<4; loop++ )
	{
		// Check for non-zero values
		if ( ip[0] | ip[1] | ip[2] | ip[3] )
		{
			t1 = (int32)(xC1S7 * ip[1]);
            t1 >>= 16;
			_A = t1; 

			t1 = (int32)(xC7S1 * ip[1]);
            t1 >>= 16;
			_B = t1 ;

			t1 = (int32)(xC3S5 * ip[3]);
            t1 >>= 16;
			_C = t1; 

			t2 = (int32)(xC5S3 * ip[3]);
            t2 >>= 16;
			_D = -t2; 

			t1 = (int32)(xC4S4 * (_A - _C));
            t1 >>= 16;
			_Ad = t1;

			t1 = (int32)(xC4S4 * (_B - _D));
            t1 >>= 16;
			_Bd = t1;
			
			_Cd = _A + _C;
			_Dd = _B + _D;

			t1 = (int32)(xC4S4 * ip[0] );
            t1 >>= 16;
			_E = t1;

			_F = t1;
			
			t1 = (int32)(xC2S6 * ip[2]);
            t1 >>= 16;
			_G = t1; 

			t1 = (int32)(xC6S2 * ip[2]);
            t1 >>= 16;
			_H = t1 ;
			
			_Ed = _E - _G;
			_Gd = _E + _G;

			_Add = _F + _Ad;
			_Bdd = _Bd - _H;
			
			_Fd = _F - _Ad;
			_Hd = _Bd + _H;
	
			// Final sequence of operations over-write original inputs.
			ip[0] = (int16)((_Gd + _Cd )   >> 0);
			ip[7] = (int16)((_Gd - _Cd )   >> 0);

			ip[1] = (int16)((_Add + _Hd )  >> 0);
			ip[2] = (int16)((_Add - _Hd )  >> 0);

			ip[3] = (int16)((_Ed + _Dd )   >> 0);
			ip[4] = (int16)((_Ed - _Dd )   >> 0);

			ip[5] = (int16)((_Fd + _Bdd )  >> 0);
			ip[6] = (int16)((_Fd - _Bdd )  >> 0);
		}

		ip += 8;			/* next row */
	}

	ip = IntermediateData;

	for ( loop=0; loop<8; loop++ )
	{	
		// Check for non-zero values (bitwise or faster than ||)
		if ( ip[0 * 8] | ip[1 * 8] | ip[2 * 8] | ip[3 * 8] )
		{
			t1 = (int32)(xC1S7 * ip[1*8]);
            t1 >>= 16;
			_A = t1 ;

			t1 = (int32)(xC7S1 * ip[1*8]);
            t1 >>= 16;
			_B = t1 ;

			t1 = (int32)(xC3S5 * ip[3*8]);
            t1 >>= 16;
			_C = t1 ;

			t2 = (int32)(xC5S3 * ip[3*8]);
            t2 >>= 16;
			_D = - t2;

			t1 = (int32)(xC4S4 * (_A - _C));
            t1 >>= 16;
			_Ad = t1;

			t1 = (int32)(xC4S4 * (_B - _D));
            t1 >>= 16;
			_Bd = t1;

			_Cd = _A + _C;
			_Dd = _B + _D;

			t1 = (int32)(xC4S4 * ip[0*8]);
            t1 >>= 16;
			_E = t1;
			_F = t1;
			
			t1 = (int32)(xC2S6 * ip[2*8]);
            t1 >>= 16;
			_G = t1;

			t1 = (int32)(xC6S2 * ip[2*8]);
            t1 >>= 16;
			_H = t1;
			
			_Ed = _E - _G;
			_Gd = _E + _G;

			_Add = _F + _Ad;
			_Bdd = _Bd - _H;
			
			_Fd = _F - _Ad;
			_Hd = _Bd + _H;
	
			_Gd += IdctAdjustBeforeShift;
			_Add += IdctAdjustBeforeShift;
			_Ed += IdctAdjustBeforeShift;
			_Fd += IdctAdjustBeforeShift;

			// Final sequence of operations over-write original inputs.
			op[0*8] = (int16)((_Gd + _Cd )  >> 4);
			op[7*8] = (int16)((_Gd - _Cd )  >> 4);

			op[1*8] = (int16)((_Add + _Hd ) >> 4);
			op[2*8] = (int16)((_Add - _Hd ) >> 4);

			op[3*8] = (int16)((_Ed + _Dd )  >> 4);
			op[4*8] = (int16)((_Ed - _Dd )  >> 4);

			op[5*8] = (int16)((_Fd + _Bdd ) >> 4);
			op[6*8] = (int16)((_Fd - _Bdd ) >> 4);
		}
		else
		{
			op[0*8] = 0;
			op[7*8] = 0;
			op[1*8] = 0;
			op[2*8] = 0;
			op[3*8] = 0;
			op[4*8] = 0;
			op[5*8] = 0;
			op[6*8] = 0;
		}

		ip++;	// next column
        op++;
	}
}

/****************************************************************************
 * 
 *  ROUTINE       : IDct1
 *
 *  INPUTS        : int16 *InputData   : Pointer to 8x8 quantized DCT coefficients.
 *                  int16 *QuantMatrix : Pointer to 8x8 quantization matrix.
 *
 *  OUTPUTS       : int16 *OutputData  : Pointer to 8x8 block to hold output.
 *
 *  RETURNS       : void
 *
 *  FUNCTION      : Inverse DCT's input 8x8 block with only one non-zero
 *                  coeff in the DC position:
 *                  
 *                          x   0   0  0  0  0  0  0
 *                          0   0   0  0  0  0  0  0
 *                          0   0   0  0  0  0  0  0
 *                          0   0   0  0  0  0  0  0
 *                          0   0   0  0  0  0  0  0
 *                          0   0   0  0  0  0  0  0
 *                          0   0   0  0  0  0  0  0
 *                          0   0   0  0  0  0  0  0
 *
 *  SPECIAL NOTES : Output data is in raster, not zig-zag, order.
 *
 ****************************************************************************/
void IDct1 ( int16 *InputData, int16 *QuantMatrix, INT16 *OutputData )
{
    INT32 loop;
	INT16 OutD;
	
	OutD = (INT16)((INT32)(InputData[0]*QuantMatrix[0]+15)>>5);

	for ( loop=0; loop<64; loop++ )
		OutputData[loop] = OutD;
}


#if 0
/****************************************************************************
 * 
 *  ROUTINE       : IDct4
 *
 *  INPUTS        : int16 *InputData   : Pointer to 8x8 DCT coefficients.
 *
 *  OUTPUTS       : int16 *OutputData  : Pointer to 8x8 block to hold output.
 *
 *  RETURNS       : void
 *
 *  FUNCTION      : Inverse DCT's input 8x8 block with at most four non-zero
 *                  coeffs in the following positions:
 *                  
 *                          x   x   0  0  0  0  0  0
 *                          x   x   0  0  0  0  0  0
 *                          0   0   0  0  0  0  0  0
 *                          0   0   0  0  0  0  0  0
 *                          0   0   0  0  0  0  0  0
 *                          0   0   0  0  0  0  0  0
 *                          0   0   0  0  0  0  0  0
 *                          0   0   0  0  0  0  0  0
 *
 *  SPECIAL NOTES : CURRENTLY NOT USED IN CODEBASE.
 *
 ****************************************************************************/
void IDct4 ( int16 *InputData, int16 *OutputData )
{
	int32 t1;
	int loop;
	int32 _Add, _Fd;
	int32 _A, _B, _Ad, _Bd, _Cd, _Dd, _E;

    int16 *ip = InputData;
	int16 *op = OutputData;

	// Unzigzag the coefficents
	ip[8] = ip[2];
	ip[9] = ip[4];
	ip[2] = 0;
	ip[5] = 0;

	// Inverse DCT on the rows now
	for ( loop = 0; loop < 2; loop++)
	{
		// Check for non-zero values
		if ( ip[0] | ip[1] )
		{
			t1 = (int32)(xC1S7 * ip[1]);
            t1 >>= 16;
			_A = t1; 

			t1 = (int32)(xC7S1 * ip[1]);
            t1 >>= 16;
			_B = t1 ;

			t1 = (int32)(xC4S4 * _A );
            t1 >>= 16;
			_Ad = t1;

			t1 = (int32)(xC4S4 * _B );
            t1 >>= 16;
			_Bd = t1;

			_Cd = _A ;
			_Dd = _B ;

			t1 = (int32)(xC4S4 * ip[0] );
            t1 >>= 16;
			_E = t1;

			_Add = _E + _Ad;
			
			_Fd = _E - _Ad;
	
			// Final sequence of operations over-write original inputs.
			ip[0] = (int16)((_E + _Cd )   >> 0);
			ip[7] = (int16)((_E - _Cd )   >> 0);

			ip[1] = (int16)((_Add + _Bd ) >> 0);
			ip[2] = (int16)((_Add - _Bd ) >> 0);

			ip[3] = (int16)((_E + _Dd )   >> 0);
			ip[4] = (int16)((_E - _Dd )   >> 0);

			ip[5] = (int16)((_Fd + _Bd )  >> 0);
			ip[6] = (int16)((_Fd - _Bd )  >> 0);
		}

		ip += 8;			/* next row */
	}

	ip = InputData;

	for ( loop=0; loop<8; loop++ )
	{	
		// Check for non-zero values (bitwise or faster than ||)
		if ( ip[0 * 8] | ip[1 * 8] )
		{

			t1 = (int32)(xC1S7 * ip[1*8]);
            t1 >>= 16;
			_A = t1 ;

			t1 = (int32)(xC7S1 * ip[1*8]);
            t1 >>= 16;
			_B = t1 ;

			t1 = (int32)(xC4S4 * _A );
            t1 >>= 16;
			_Ad = t1;

			t1 = (int32)(xC4S4 * _B );
            t1 >>= 16;
			_Bd = t1;
			
			_Cd = _A ;
			_Dd = _B ;

			t1 = (int32)(xC4S4 * ip[0*8]);
            t1 >>= 16;
			_E = t1;

			_Add = _E + _Ad;
			
			_Fd = _E - _Ad;
	
			_Add += IdctAdjustBeforeShift;
			_E   += IdctAdjustBeforeShift;
			_Fd  += IdctAdjustBeforeShift;

			// Final sequence of operations over-write original inputs.
			op[0*8] = (int16)((_E + _Cd )   >> 4);
			op[7*8] = (int16)((_E - _Cd )   >> 4);

			op[1*8] = (int16)((_Add + _Bd ) >> 4);
			op[2*8] = (int16)((_Add - _Bd ) >> 4);

			op[3*8] = (int16)((_E + _Dd )   >> 4);
			op[4*8] = (int16)((_E - _Dd )   >> 4);

			op[5*8] = (int16)((_Fd + _Bd )   >> 4);
			op[6*8] = (int16)((_Fd - _Bd )   >> 4);
		}
		else
		{
			op[0*8] = 0;
			op[7*8] = 0;
			op[1*8] = 0;
			op[2*8] = 0;
			op[3*8] = 0;
			op[4*8] = 0;
			op[5*8] = 0;
			op[6*8] = 0;
		}

		ip++;	// next column
        op++;
	}
}
#endif