+++ /dev/null
-//
-// MMX32 iDCT algorithm (IEEE-1180 compliant) :: idct_mmx32()
-//
-// MPEG2AVI
-// --------
-// v0.16B33 initial release
-//
-// This was one of the harder pieces of work to code.
-// Intel's app-note focuses on the numerical issues of the algorithm, but
-// assumes the programmer is familiar with IDCT mathematics, leaving the
-// form of the complete function up to the programmer's imagination.
-
-#include "config.h"
-#include "mpeg2enc.h"
-#include "global.h"
-#include "simd.h"
-
-// ALGORITHM OVERVIEW
-// ------------------
-// I played around with the code for quite a few hours. I came up
-// with *A* working IDCT algorithm, however I'm not sure whether my routine
-// is "the correct one." But rest assured, my code passes all six IEEE
-// accuracy tests with plenty of margin.
-//
-// My IDCT algorithm consists of 4 steps:
-//
-// 1) IDCT-row transformation (using the IDCT-row function) on all 8 rows
-// This yields an intermediate 8x8 matrix.
-//
-// 2) intermediate matrix transpose (mandatory)
-//
-// 3) IDCT-row transformation (2nd time) on all 8 rows of the intermediate
-// matrix. The output is the final-result, in transposed form.
-//
-// 4) post-transformation matrix transpose
-// (not necessary if the input-data is already transposed, this could
-// be done during the MPEG "zig-zag" scan, but since my algorithm
-// requires at least one transpose operation, why not re-use the
-// transpose-code.)
-//
-// Although the (1st) and (3rd) steps use the SAME row-transform operation,
-// the (3rd) step uses different shift&round constants (explained later.)
-//
-// Also note that the intermediate transpose (2) would not be neccessary,
-// if the subsequent operation were a iDCT-column transformation. Since
-// we only have the iDCT-row transform, we transpose the intermediate
-// matrix and use the iDCT-row transform a 2nd time.
-//
-// I had to change some constants/variables for my method to work :
-//
-// As given by Intel, the #defines for SHIFT_INV_COL and RND_INV_COL are
-// wrong. Not surprising since I'm not using a true column-transform
-// operation, but the row-transform operation (as mentioned earlier.)
-// round_inv_col[], which is given as "4 int16_t" values, should have the
-// same dimensions as round_inv_row[]. The corrected variables are
-// shown.
-//
-// Intel's code defines a different table for each each row operation.
-// The tables given are 0/4, 1/7, 2/6, and 5/3. My code only uses row#0.
-// Using the other rows messes up the overall transform.
-//
-// IMPLEMENTATION DETAILs
-// ----------------------
-//
-// I divided the algorithm's work into two subroutines,
-// 1) idct_mmx32_rows() - transforms 8 rows, then transpose
-// 2) idct_mmx32_cols() - transforms 8 rows, then transpose
-// yields final result ("drop-in" direct replacement for INT32 IDCT)
-//
-// The 2nd function is a clone of the 1st, with changes made only to the
-// shift&rounding instructions.
-//
-// In the 1st function (rows), the shift & round instructions use
-// SHIFT_INV_ROW & round_inv_row[] (renamed to r_inv_row[])
-//
-// In the 2nd function (cols)-> r_inv_col[], and
-// SHIFT_INV_COL & round_inv_col[] (renamed to r_inv_col[])
-//
-// Each function contains an integrated transpose-operator, which comes
-// AFTER the primary transformation operation. In the future, I'll optimize
-// the code to do more of the transpose-work "in-place". Right now, I've
-// left the code as two subroutines and a main calling function, so other
-// people can read the code more easily.
-//
-// liaor@umcc.ais.org http://members.tripod.com/~liaor
-//
-
-//;=============================================================================
-//;
-//; AP-922 http://developer.intel.com/vtune/cbts/strmsimd
-//; These examples contain code fragments for first stage iDCT 8x8
-//; (for rows) and first stage DCT 8x8 (for columns)
-//;
-//;=============================================================================
-
-#define BITS_INV_ACC 4 //; 4 or 5 for IEEE
- // 5 yields higher accuracy, but lessens dynamic range on the input matrix
-#define SHIFT_INV_ROW (16 - BITS_INV_ACC)
-#define SHIFT_INV_COL (1 + BITS_INV_ACC +14 ) // changed from Intel's val)
-
-
-#define RND_INV_ROW (1 << (SHIFT_INV_ROW-1))
-#define RND_INV_COL (1 << (SHIFT_INV_COL-1))
-#define RND_INV_CORR (RND_INV_COL - 1) //; correction -1.0 and round
-
-/* TODO: This should *really* be aligned on 16-byte boundaries... */
-
-const int idct_r_inv_row[2] = { RND_INV_ROW, RND_INV_ROW};
-const int idct_r_inv_col[2] = {RND_INV_COL, RND_INV_COL};
-const int idct_r_inv_corr[2] = {RND_INV_CORR, RND_INV_CORR };
-
-/* Unused and thus redundant...
-const long long dct_one_corr = 0x0001000100010001;
-*/
-
-/*
-;=============================================================================
-;
-; The first stage iDCT 8x8 - inverse DCTs of rows
-;
-;-----------------------------------------------------------------------------
-; The 8-point inverse DCT direct algorithm
-;-----------------------------------------------------------------------------
-;
-; static const int16_t w[32] = {
-; FIX(cos_4_16), FIX(cos_2_16), FIX(cos_4_16), FIX(cos_6_16),
-; FIX(cos_4_16), FIX(cos_6_16), -FIX(cos_4_16), -FIX(cos_2_16),
-; FIX(cos_4_16), -FIX(cos_6_16), -FIX(cos_4_16), FIX(cos_2_16),
-; FIX(cos_4_16), -FIX(cos_2_16), FIX(cos_4_16), -FIX(cos_6_16),
-; FIX(cos_1_16), FIX(cos_3_16), FIX(cos_5_16), FIX(cos_7_16),
-; FIX(cos_3_16), -FIX(cos_7_16), -FIX(cos_1_16), -FIX(cos_5_16),
-; FIX(cos_5_16), -FIX(cos_1_16), FIX(cos_7_16), FIX(cos_3_16),
-; FIX(cos_7_16), -FIX(cos_5_16), FIX(cos_3_16), -FIX(cos_1_16) };
-;
-; #define DCT_8_INV_ROW(x, y)
-
-;{
-; int a0, a1, a2, a3, b0, b1, b2, b3;
-;
-; a0 =x[0]*w[0]+x[2]*w[1]+x[4]*w[2]+x[6]*w[3];
-; a1 =x[0]*w[4]+x[2]*w[5]+x[4]*w[6]+x[6]*w[7];
-; a2 = x[0] * w[ 8] + x[2] * w[ 9] + x[4] * w[10] + x[6] * w[11];
-; a3 = x[0] * w[12] + x[2] * w[13] + x[4] * w[14] + x[6] * w[15];
-; b0 = x[1] * w[16] + x[3] * w[17] + x[5] * w[18] + x[7] * w[19];
-; b1 = x[1] * w[20] + x[3] * w[21] + x[5] * w[22] + x[7] * w[23];
-; b2 = x[1] * w[24] + x[3] * w[25] + x[5] * w[26] + x[7] * w[27];
-; b3 = x[1] * w[28] + x[3] * w[29] + x[5] * w[30] + x[7] * w[31];
-;
-; y[0] = SHIFT_ROUND ( a0 + b0 );
-; y[1] = SHIFT_ROUND ( a1 + b1 );
-; y[2] = SHIFT_ROUND ( a2 + b2 );
-; y[3] = SHIFT_ROUND ( a3 + b3 );
-; y[4] = SHIFT_ROUND ( a3 - b3 );
-; y[5] = SHIFT_ROUND ( a2 - b2 );
-; y[6] = SHIFT_ROUND ( a1 - b1 );
-; y[7] = SHIFT_ROUND ( a0 - b0 );
-;}
-;
-;-----------------------------------------------------------------------------
-;
-; In this implementation the outputs of the iDCT-1D are multiplied
-; for rows 0,4 - by cos_4_16,
-; for rows 1,7 - by cos_1_16,
-; for rows 2,6 - by cos_2_16,
-; for rows 3,5 - by cos_3_16
-; and are shifted to the left for better accuracy
-;
-; For the constants used,
-; FIX(float_const) = (int16_t) (float_const * (1<<15) + 0.5)
-;
-;=============================================================================
-*/
-
-/* CONCATENATED TABLE, rows 0,1,2,3,4,5,6,7 (in order )
-
- In our implementation, however, we only use row0 !
-*/
-
-const int16_t idct_tab_01234567[] = {
- //row0, this row is required
- 16384, 16384, 16384, -16384, // ; movq-> w06 w04 w02 w00
- 21407, 8867, 8867, -21407, // w07 w05 w03 w01
- 16384, -16384, 16384, 16384, //; w14 w12 w10 w08
- -8867, 21407, -21407, -8867, //; w15 w13 w11 w09
- 22725, 12873, 19266, -22725, //; w22 w20 w18 w16
- 19266, 4520, -4520, -12873, //; w23 w21 w19 w17
- 12873, 4520, 4520, 19266, //; w30 w28 w26 w24
- -22725, 19266, -12873, -22725, //w31 w29 w27 w25
-
- // the rest of these rows (1-7), aren't used !
-
- //row1
- 22725, 22725, 22725, -22725, // ; movq-> w06 w04 w02 w00
- 29692, 12299, 12299, -29692, // ; w07 w05 w03 w01
- 22725, -22725, 22725, 22725, //; w14 w12 w10 w08
- -12299, 29692, -29692, -12299, //; w15 w13 w11 w09
- 31521, 17855, 26722, -31521, //; w22 w20 w18 w16
- 26722, 6270, -6270, -17855, //; w23 w21 w19 w17
- 17855, 6270, 6270, 26722, //; w30 w28 w26 w24
- -31521, 26722, -17855, -31521, // w31 w29 w27 w25
-
- //row2
- 21407, 21407, 21407, -21407, // ; movq-> w06 w04 w02 w00
- 27969, 11585, 11585, -27969, // ; w07 w05 w03 w01
- 21407, -21407, 21407, 21407, // ; w14 w12 w10 w08
- -11585, 27969, -27969, -11585, // ;w15 w13 w11 w09
- 29692, 16819, 25172, -29692, // ;w22 w20 w18 w16
- 25172, 5906, -5906, -16819, // ;w23 w21 w19 w17
- 16819, 5906, 5906, 25172, // ;w30 w28 w26 w24
- -29692, 25172, -16819, -29692, // ;w31 w29 w27 w25
-
- //row3
- 19266, 19266, 19266, -19266, //; movq-> w06 w04 w02 w00
- 25172, 10426, 10426, -25172, //; w07 w05 w03 w01
- 19266, -19266, 19266, 19266, //; w14 w12 w10 w08
- -10426, 25172, -25172, -10426, //; w15 w13 w11 w09
- 26722, 15137, 22654, -26722, //; w22 w20 w18 w16
- 22654, 5315, -5315, -15137, //; w23 w21 w19 w17
- 15137, 5315, 5315, 22654, //; w30 w28 w26 w24
- -26722, 22654, -15137, -26722, //; w31 w29 w27 w25
-
- //row4
- 16384, 16384, 16384, -16384, // ; movq-> w06 w04 w02 w00
- 21407, 8867, 8867, -21407, // w07 w05 w03 w01
- 16384, -16384, 16384, 16384, //; w14 w12 w10 w08
- -8867, 21407, -21407, -8867, //; w15 w13 w11 w09
- 22725, 12873, 19266, -22725, //; w22 w20 w18 w16
- 19266, 4520, -4520, -12873, //; w23 w21 w19 w17
- 12873, 4520, 4520, 19266, //; w30 w28 w26 w24
- -22725, 19266, -12873, -22725, //w31 w29 w27 w25
-
- //row5
- 19266, 19266, 19266, -19266, //; movq-> w06 w04 w02 w00
- 25172, 10426, 10426, -25172, //; w07 w05 w03 w01
- 19266, -19266, 19266, 19266, //; w14 w12 w10 w08
- -10426, 25172, -25172, -10426, //; w15 w13 w11 w09
- 26722, 15137, 22654, -26722, //; w22 w20 w18 w16
- 22654, 5315, -5315, -15137, //; w23 w21 w19 w17
- 15137, 5315, 5315, 22654, //; w30 w28 w26 w24
- -26722, 22654, -15137, -26722, //; w31 w29 w27 w25
-
- //row6
- 21407, 21407, 21407, -21407, // ; movq-> w06 w04 w02 w00
- 27969, 11585, 11585, -27969, // ; w07 w05 w03 w01
- 21407, -21407, 21407, 21407, // ; w14 w12 w10 w08
- -11585, 27969, -27969, -11585, // ;w15 w13 w11 w09
- 29692, 16819, 25172, -29692, // ;w22 w20 w18 w16
- 25172, 5906, -5906, -16819, // ;w23 w21 w19 w17
- 16819, 5906, 5906, 25172, // ;w30 w28 w26 w24
- -29692, 25172, -16819, -29692, // ;w31 w29 w27 w25
-
- //row7
- 22725, 22725, 22725, -22725, // ; movq-> w06 w04 w02 w00
- 29692, 12299, 12299, -29692, // ; w07 w05 w03 w01
- 22725, -22725, 22725, 22725, //; w14 w12 w10 w08
- -12299, 29692, -29692, -12299, //; w15 w13 w11 w09
- 31521, 17855, 26722, -31521, //; w22 w20 w18 w16
- 26722, 6270, -6270, -17855, //; w23 w21 w19 w17
- 17855, 6270, 6270, 26722, //; w30 w28 w26 w24
- -31521, 26722, -17855, -31521}; // w31 w29 w27 w25
projects / goodguy / history.git / blobdiff