hvirtual/mpeg2enc/idct_mmx.s

   1 ;
   2 ; MMX32 iDCT algorithm  (IEEE-1180 compliant) :: idct_mmx32()
   3 ;
   4 ; MPEG2AVI
   5 ; --------
   6 ;  v0.16B33 initial release
   7 ;
   8 ; This was one of the harder pieces of work to code.
   9 ; Intel's app-note focuses on the numerical issues of the algorithm, but
  10 ; assumes the programmer is familiar with IDCT mathematics, leaving the
  11 ; form of the complete function up to the programmer's imagination.
  12 ;
  13 ;  ALGORITHM OVERVIEW
  14 ;  ------------------
  15 ; I played around with the code for quite a few hours.  I came up
  16 ; with *A* working IDCT algorithm, however I'm not sure whether my routine
  17 ; is "the correct one."  But rest assured, my code passes all six IEEE
  18 ; accuracy tests with plenty of margin.
  19 ;
  20 ;   My IDCT algorithm consists of 4 steps:
  21 ;
  22 ;   1) IDCT-row transformation (using the IDCT-row function) on all 8 rows
  23 ;      This yields an intermediate 8x8 matrix.
  24 ;
  25 ;   2) intermediate matrix transpose (mandatory)
  26 ;
  27 ;   3) IDCT-row transformation (2nd time) on all 8 rows of the intermediate
  28 ;      matrix.  The output is the final-result, in transposed form.
  29 ;
  30 ;   4) post-transformation matrix transpose
  31 ;      (not necessary if the input-data is already transposed, this could
  32 ;       be done during the MPEG "zig-zag" scan, but since my algorithm
  33 ;       requires at least one transpose operation, why not re-use the
  34 ;       transpose-code.)
  35 ;
  36 ;   Although the (1st) and (3rd) steps use the SAME row-transform operation,
  37 ;   the (3rd) step uses different shift&round constants (explained later.)
  38 ;
  39 ;   Also note that the intermediate transpose (2) would not be neccessary,
  40 ;   if the subsequent operation were a iDCT-column transformation.  Since
  41 ;   we only have the iDCT-row transform, we transpose the intermediate
  42 ;   matrix and use the iDCT-row transform a 2nd time.
  43 ;
  44 ;   I had to change some constants/variables for my method to work :
  45 ;
  46 ;      As given by Intel, the #defines for SHIFT_INV_COL and RND_INV_COL are
  47 ;      wrong.  Not surprising since I'm not using a true column-transform
  48 ;      operation, but the row-transform operation (as mentioned earlier.)
  49 ;      round_inv_col[], which is given as "4 short" values, should have the
  50 ;      same dimensions as round_inv_row[].  The corrected variables are
  51 ;      shown.
  52 ;
  53 ;      Intel's code defines a different table for each each row operation.
  54 ;      The tables given are 0/4, 1/7, 2/6, and 5/3.  My code only uses row#0.
  55 ;      Using the other rows messes up the overall transform.
  56 ;
  57 ;   IMPLEMENTATION DETAILs
  58 ;   ----------------------
  59 ;
  60 ;   I divided the algorithm's work into two subroutines,
  61 ;    1) idct_mmx32_rows() - transforms 8 rows, then transpose
  62 ;    2) idct_mmx32_cols() - transforms 8 rows, then transpose
  63 ;       yields final result ("drop-in" direct replacement for INT32 IDCT)
  64 ;
  65 ;   The 2nd function is a clone of the 1st, with changes made only to the
  66 ;   shift&rounding instructions.
  67 ;
  68 ;      In the 1st function (rows), the shift & round instructions use
  69 ;       SHIFT_INV_ROW & round_inv_row[] (renamed to r_inv_row[])
  70 ;
  71 ;      In the 2nd function (cols)-> r_inv_col[], and
  72 ;       SHIFT_INV_COL & round_inv_col[] (renamed to r_inv_col[])
  73 ;
  74 ;   Each function contains an integrated transpose-operator, which comes
  75 ;   AFTER the primary transformation operation.  In the future, I'll optimize
  76 ;   the code to do more of the transpose-work "in-place".  Right now, I've
  77 ;   left the code as two subroutines and a main calling function, so other
  78 ;   people can read the code more easily.
  79 ;
  80 ;   liaor@umcc.ais.org  http:;members.tripod.com/~liaor
  81 ;
  82
  83 ;;;
  84 ;;; A.Stevens Jul 2000 easy-peasy quick port to nasm
  85 ;;; Isn't open source a sensible idea...
  86 ;;;
  87
  88 ;=============================================================================
  89 ;
  90 ;  AP-922   http:;developer.intel.com/vtune/cbts/strmsimd
  91 ; These examples contain code fragments for first stage iDCT 8x8
  92 ; (for rows) and first stage DCT 8x8 (for columns)
  93 ;
  94 ;============================================================================
  95
  96 %define INP eax         ; pointer to (short *blk)
  97 %define OUT ecx         ; pointer to output (temporary store space qwTemp[])
  98 %define TABLE ebx       ; pointer to idct_tab_01234567[]
  99 %define round_inv_row edx
 100 %define round_inv_col edx
 101
 102
 103 %define ROW_STRIDE 16                                                   ; for 8x8 matrix transposer
 104 %define BITS_INV_ACC    4                                               ; 4 or 5 for IEEE
 105 %define SHIFT_INV_ROW   (16 - BITS_INV_ACC)
 106 %define SHIFT_INV_COL   (1 + BITS_INV_ACC +14 ) ;  changed from Intel's val)
 107
 108                 ;;
 109                 ;; Variables and tables defined in C for convenience
 110                 ;;
 111 extern  idct_r_inv_row                          ; 2 DWORDSs
 112 extern  idct_r_inv_col                          ;    "
 113 extern  idct_r_inv_corr                         ;    "
 114 extern idct_tab_01234567                ; Catenated table of coefficients
 115
 116                 ;;
 117                 ;;  private variables and functions
 118                 ;;
 119
 120 SECTION .bss
 121 align 16
 122 ; qwTemp:               resw 64                         ; temporary storage space, 8x8 of shorts
 123
 124
 125 SECTION .text
 126
 127                 ;; static void idct_mmx( short *blk
 128 global idct_mmx
 129
 130 idct_mmx:
 131         push ebp                        ; save frame pointer
 132         mov ebp, esp            ; link
 133
 134         push ebx
 135         push ecx
 136         push edx
 137         push edi
 138
 139                 ;;
 140                 ;; transform all 8 rows of 8x8 iDCT block
 141                 ;;
 142
 143         ; this subroutine performs two operations
 144         ; 1) iDCT row transform
 145         ;               for( i = 0; i < 8; ++ i)
 146         ;                       DCT_8_INV_ROW_1( blk[i*8], qwTemp[i] );
 147         ;
 148         ; 2) transpose the matrix (which was stored in qwTemp[])
 149         ;        qwTemp[] -> [8x8 matrix transpose] -> blk[]
 150
 151         mov INP, [ebp+8]                        ; INP = blk
 152         mov edi, 0x00;                          ; x = 0
 153         lea TABLE,[idct_tab_01234567]; ; row 0
 154
 155
 156 ;       lea OUT,   [qwTemp];
 157         mov OUT,    [ebp+12];
 158         lea round_inv_row,   [idct_r_inv_row]
 159     jmp lpa
 160
 161         ; for ( x = 0; x < 8; ++x )  ; transform one row per iteration
 162 align 32
 163 lpa:
 164         movq mm0,   [INP]               ; 0 ; x3 x2 x1 x0
 165
 166         movq mm1,   [INP+8]     ; 1 ; x7 x6 x5 x4
 167         movq mm2, mm0 ;                         ; 2 ; x3 x2 x1 x0
 168
 169         movq mm3,   [TABLE]     ; 3 ; w06 w04 w02 w00
 170         punpcklwd mm0, mm1                      ; x5 x1 x4 x0
 171
 172 ; ----------
 173         movq mm5, mm0 ;                                 ; 5 ; x5 x1 x4 x0
 174         punpckldq mm0, mm0 ;                    ; x4 x0 x4 x0
 175
 176         movq mm4,   [TABLE+8] ; ; 4 ; w07 w05 w03 w01
 177         punpckhwd mm2, mm1 ;                    ; 1 ; x7 x3 x6 x2
 178
 179         pmaddwd mm3, mm0 ;                              ; x4*w06+x0*w04 x4*w02+x0*w00
 180         movq mm6, mm2 ;                         ; 6 ; x7 x3 x6 x2
 181
 182         movq mm1,   [TABLE+32] ;; 1 ; w22 w20 w18 w16
 183         punpckldq mm2, mm2 ;                    ; x6 x2 x6 x2
 184
 185         pmaddwd mm4, mm2 ;                              ; x6*w07+x2*w05 x6*w03+x2*w01
 186         punpckhdq mm5, mm5 ;                    ; x5 x1 x5 x1
 187
 188         pmaddwd mm0,   [TABLE+16] ;; x4*w14+x0*w12 x4*w10+x0*w08
 189         punpckhdq mm6, mm6 ;                    ; x7 x3 x7 x3
 190
 191         movq mm7,   [TABLE+40] ;; 7 ; w23 w21 w19 w17
 192         pmaddwd mm1, mm5 ;                              ; x5*w22+x1*w20 x5*w18+x1*w16
 193
 194         paddd mm3,   [round_inv_row];; +rounder
 195         pmaddwd mm7, mm6 ;                              ; x7*w23+x3*w21 x7*w19+x3*w17
 196
 197         pmaddwd mm2,   [TABLE+24] ;; x6*w15+x2*w13 x6*w11+x2*w09
 198         paddd mm3, mm4 ;                                ; 4 ; a1=sum(even1) a0=sum(even0)
 199
 200         pmaddwd mm5,   [TABLE+48] ;; x5*w30+x1*w28 x5*w26+x1*w24
 201         movq mm4, mm3 ;                         ; 4 ; a1 a0
 202
 203         pmaddwd mm6,   [TABLE+56] ;; x7*w31+x3*w29 x7*w27+x3*w25
 204         paddd mm1, mm7 ;                                ; 7 ; b1=sum(odd1) b0=sum(odd0)
 205
 206         paddd mm0,   [round_inv_row];; +rounder
 207         psubd mm3, mm1 ;                                ; a1-b1 a0-b0
 208
 209         psrad mm3, SHIFT_INV_ROW ;              ; y6=a1-b1 y7=a0-b0
 210         paddd mm1, mm4 ;                                ; 4 ; a1+b1 a0+b0
 211
 212         paddd mm0, mm2 ;                                ; 2 ; a3=sum(even3) a2=sum(even2)
 213         psrad mm1, SHIFT_INV_ROW ;              ; y1=a1+b1 y0=a0+b0
 214
 215         paddd mm5, mm6 ;                                ; 6 ; b3=sum(odd3) b2=sum(odd2)
 216         movq mm4, mm0 ;                         ; 4 ; a3 a2
 217
 218         paddd mm0, mm5 ;                                ; a3+b3 a2+b2
 219         psubd mm4, mm5 ;                                ; 5 ; a3-b3 a2-b2
 220
 221         add INP, 16;                                    ; increment INPUT pointer -> row 1
 222         psrad mm4, SHIFT_INV_ROW ;              ; y4=a3-b3 y5=a2-b2
 223
 224 ;       add TABLE, 0;                                   ;  TABLE += 64 -> row 1
 225         psrad mm0, SHIFT_INV_ROW ;              ; y3=a3+b3 y2=a2+b2
 226
 227 ;       movq mm2,   [INP] ;             ; row+1; 0;  x3 x2 x1 x0
 228         packssdw mm4, mm3 ;                             ; 3 ; y6 y7 y4 y5
 229
 230         packssdw mm1, mm0 ;                             ; 0 ; y3 y2 y1 y0
 231         movq mm7, mm4 ;                         ; 7 ; y6 y7 y4 y5
 232
 233 ;       movq mm0, mm2 ;                                 ; row+1;  2 ; x3 x2 x1 x0
 234         psrld mm4, 16 ;                                 ; 0 y6 0 y4
 235
 236         movq   [OUT], mm1 ;     ; 1 ; save y3 y2 y1 y0
 237         pslld mm7, 16 ;                                 ; y7 0 y5 0
 238
 239 ;       movq mm1,   [INP+8] ;   ; row+1;  1 ; x7 x6 x5 x4
 240         por mm7, mm4 ;                                  ; 4 ; y7 y6 y5 y4
 241
 242         movq mm3,   [TABLE] ;   ; 3 ; w06 w04 w02 w00
 243 ;        punpcklwd mm0, mm1 ;                   ; row+1;  x5 x1 x4 x0
 244
 245    ; begin processing row 1
 246         movq   [OUT+8], mm7 ;   ; 7 ; save y7 y6 y5 y4
 247         add edi, 0x01;
 248
 249         add OUT, 16;                                    ; increment OUTPUT pointer -> row 1
 250         cmp edi, 0x08;
 251         jl near lpa;            ; end for ( x = 0; x < 8; ++x )
 252
 253         ; done with the iDCT row-transformation
 254
 255         ; now we have to transpose the output 8x8 matrix
 256         ; 8x8 (OUT) -> 8x8't' (IN)
 257         ; the transposition is implemented as 4 sub-operations.
 258         ; 1) transpose upper-left quad
 259         ; 2) transpose lower-right quad
 260         ; 3) transpose lower-left quad
 261         ; 4) transpose upper-right quad
 262
 263
 264         ; mm0 = 1st row [ A B C D ] row1
 265         ; mm1 = 2nd row [ E F G H ] 2
 266         ; mm2 = 3rd row [ I J K L ] 3
 267         ; mm3 = 4th row [ M N O P ] 4
 268
 269                         ; 1) transpose upper-left quad
 270 ;       lea OUT,   [qwTemp];
 271         mov OUT,    [ebp+12];
 272
 273         movq mm0,   [OUT + ROW_STRIDE * 0 ]
 274
 275         movq mm1,   [OUT + ROW_STRIDE * 1 ]
 276         movq mm4, mm0;  ; mm4 = copy of row1[A B C D]
 277
 278         movq mm2,   [OUT + ROW_STRIDE * 2 ]
 279         punpcklwd mm0, mm1; ; mm0 = [ 0 4 1 5]
 280
 281         movq mm3,   [OUT + ROW_STRIDE * 3]
 282         punpckhwd mm4, mm1; ; mm4 = [ 2 6 3 7]
 283
 284         movq mm6, mm2;
 285         punpcklwd mm2, mm3;     ; mm2 = [ 8 12 9 13]
 286
 287         punpckhwd mm6, mm3;     ; mm6 = 10 14 11 15]
 288         movq mm1, mm0;  ; mm1 = [ 0 4 1 5]
 289
 290         mov INP,   [ebp+8];     ; load input address
 291         punpckldq mm0, mm2;     ; final result mm0 = row1 [0 4 8 12]
 292
 293         movq mm3, mm4;  ; mm3 = [ 2 6 3 7]
 294         punpckhdq mm1, mm2; ; mm1 = final result mm1 = row2 [1 5 9 13]
 295
 296         movq   [ INP + ROW_STRIDE * 0 ], mm0; ; store row 1
 297         punpckldq mm4, mm6; ; final result mm4 = row3 [2 6 10 14]
 298
 299                 ; begin reading next quadrant (lower-right)
 300         movq mm0,   [OUT + ROW_STRIDE*4 + 8];
 301         punpckhdq mm3, mm6; ; final result mm3 = row4 [3 7 11 15]
 302
 303         movq   [ INP +ROW_STRIDE * 2], mm4; ; store row 3
 304         movq mm4, mm0;  ; mm4 = copy of row1[A B C D]
 305
 306         movq   [ INP +ROW_STRIDE * 1], mm1; ; store row 2
 307
 308         movq mm1,   [OUT + ROW_STRIDE*5 + 8]
 309
 310         movq   [ INP +ROW_STRIDE * 3], mm3; ; store row 4
 311         punpcklwd mm0, mm1; ; mm0 = [ 0 4 1 5]
 312
 313                         ; 2) transpose lower-right quadrant
 314
 315 ;       movq mm0,   [OUT + ROW_STRIDE*4 + 8]
 316
 317 ;       movq mm1,   [OUT + ROW_STRIDE*5 + 8]
 318 ;        movq mm4, mm0; ; mm4 = copy of row1[A B C D]
 319
 320         movq mm2,   [OUT + ROW_STRIDE*6 + 8]
 321 ;        punpcklwd mm0, mm1; ; mm0 = [ 0 4 1 5]
 322         punpckhwd mm4, mm1; ; mm4 = [ 2 6 3 7]
 323
 324         movq mm3,   [OUT + ROW_STRIDE*7 + 8]
 325         movq mm6, mm2;
 326
 327         punpcklwd mm2, mm3;     ; mm2 = [ 8 12 9 13]
 328         movq mm1, mm0;  ; mm1 = [ 0 4 1 5]
 329
 330         punpckhwd mm6, mm3;     ; mm6 = 10 14 11 15]
 331         movq mm3, mm4;  ; mm3 = [ 2 6 3 7]
 332
 333         punpckldq mm0, mm2;     ; final result mm0 = row1 [0 4 8 12]
 334
 335         punpckhdq mm1, mm2; ; mm1 = final result mm1 = row2 [1 5 9 13]
 336         ; ; slot
 337
 338         movq   [ INP + ROW_STRIDE*4 + 8], mm0; ; store row 1
 339          punpckldq mm4, mm6; ; final result mm4 = row3 [2 6 10 14]
 340
 341         movq mm0,   [OUT + ROW_STRIDE * 4 ]
 342         punpckhdq mm3, mm6; ; final result mm3 = row4 [3 7 11 15]
 343         movq   [ INP +ROW_STRIDE*6 + 8], mm4; ; store row 3
 344          movq mm4, mm0; ; mm4 = copy of row1[A B C D]
 345         movq   [ INP +ROW_STRIDE*5 + 8], mm1; ; store row 2
 346          ; ;  slot
 347         movq mm1,   [OUT + ROW_STRIDE * 5 ]
 348          ; ;  slot
 349
 350         movq   [ INP +ROW_STRIDE*7 + 8], mm3; ; store row 4
 351         punpcklwd mm0, mm1; ; mm0 = [ 0 4 1 5]
 352
 353   ; 3) transpose lower-left
 354 ;       movq mm0,   [OUT + ROW_STRIDE * 4 ]
 355
 356 ;       movq mm1,   [OUT + ROW_STRIDE * 5 ]
 357 ;        movq mm4, mm0; ; mm4 = copy of row1[A B C D]
 358
 359         movq mm2,   [OUT + ROW_STRIDE * 6 ]
 360 ;        punpcklwd mm0, mm1; ; mm0 = [ 0 4 1 5]
 361         punpckhwd mm4, mm1; ; mm4 = [ 2 6 3 7]
 362
 363         movq mm3,   [OUT + ROW_STRIDE * 7 ]
 364         movq mm6, mm2;
 365
 366         punpcklwd mm2, mm3;     ; mm2 = [ 8 12 9 13]
 367         movq mm1, mm0;  ; mm1 = [ 0 4 1 5]
 368
 369         punpckhwd mm6, mm3;     ; mm6 = 10 14 11 15]
 370          movq mm3, mm4; ; mm3 = [ 2 6 3 7]
 371
 372         punpckldq mm0, mm2;     ; final result mm0 = row1 [0 4 8 12]
 373
 374         punpckhdq mm1, mm2; ; mm1 = final result mm1 = row2 [1 5 9 13]
 375          ; ; slot
 376
 377         movq   [ INP + ROW_STRIDE * 0 + 8 ], mm0; ; store row 1
 378          punpckldq mm4, mm6; ; final result mm4 = row3 [2 6 10 14]
 379
 380 ; begin reading next quadrant (upper-right)
 381         movq mm0,   [OUT + ROW_STRIDE*0 + 8];
 382         punpckhdq mm3, mm6; ; final result mm3 = row4 [3 7 11 15]
 383
 384         movq   [ INP +ROW_STRIDE * 2 + 8], mm4; ; store row 3
 385         movq mm4, mm0;  ; mm4 = copy of row1[A B C D]
 386
 387         movq   [ INP +ROW_STRIDE * 1 + 8 ], mm1; ; store row 2
 388         movq mm1,   [OUT + ROW_STRIDE*1 + 8]
 389
 390         movq   [ INP +ROW_STRIDE * 3 + 8], mm3; ; store row 4
 391         punpcklwd mm0, mm1; ; mm0 = [ 0 4 1 5]
 392
 393
 394         ; 2) transpose lower-right quadrant
 395
 396 ;       movq mm0,   [OUT + ROW_STRIDE*4 + 8]
 397
 398 ;       movq mm1,   [OUT + ROW_STRIDE*5 + 8]
 399 ;        movq mm4, mm0; ; mm4 = copy of row1[A B C D]
 400
 401         movq mm2,   [OUT + ROW_STRIDE*2 + 8]
 402 ;        punpcklwd mm0, mm1; ; mm0 = [ 0 4 1 5]
 403          punpckhwd mm4, mm1; ; mm4 = [ 2 6 3 7]
 404
 405         movq mm3,   [OUT + ROW_STRIDE*3 + 8]
 406         movq mm6, mm2;
 407
 408         punpcklwd mm2, mm3;     ; mm2 = [ 8 12 9 13]
 409         movq mm1, mm0;  ; mm1 = [ 0 4 1 5]
 410
 411         punpckhwd mm6, mm3;     ; mm6 = 10 14 11 15]
 412         movq mm3, mm4;  ; mm3 = [ 2 6 3 7]
 413
 414         punpckldq mm0, mm2;     ; final result mm0 = row1 [0 4 8 12]
 415
 416         punpckhdq mm1, mm2; ; mm1 = final result mm1 = row2 [1 5 9 13]
 417         ; ; slot
 418
 419         movq   [ INP + ROW_STRIDE*4 ], mm0; ; store row 1
 420         punpckldq mm4, mm6; ; final result mm4 = row3 [2 6 10 14]
 421
 422         movq   [ INP +ROW_STRIDE*5 ], mm1; ; store row 2
 423         punpckhdq mm3, mm6; ; final result mm3 = row4 [3 7 11 15]
 424
 425         movq   [ INP +ROW_STRIDE*6 ], mm4; ; store row 3
 426          ; ;  slot
 427
 428         movq   [ INP +ROW_STRIDE*7 ], mm3; ; store row 4
 429
 430         ; Conceptually this is the column transform.
 431         ; Actually, the matrix is transformed
 432         ; row by row.  This function is identical to idct_mmx32_rows(),
 433         ; except for the SHIFT amount and ROUND_INV amount.
 434
 435         ; this subroutine performs two operations
 436         ; 1) iDCT row transform
 437         ;               for( i = 0; i < 8; ++ i)
 438         ;                       DCT_8_INV_ROW_1( blk[i*8], qwTemp[i] );
 439         ;
 440         ; 2) transpose the matrix (which was stored in qwTemp[])
 441         ;        qwTemp[] -> [8x8 matrix transpose] -> blk[]
 442
 443
 444         mov INP,   [ebp+8];             ; ; row 0
 445         mov edi, 0x00;  ; x = 0
 446
 447         lea TABLE,   [idct_tab_01234567]; ; row 0
 448 ;       lea OUT,   [qwTemp];
 449         mov OUT,    [ebp+12];
 450 ;        mov OUT, INP;  ; algorithm writes data in-place  -> row 0
 451
 452         lea round_inv_col,   [idct_r_inv_col]
 453     jmp acc_idct_colloop1
 454
 455         ; for ( x = 0; x < 8; ++x )  ; transform one row per iteration
 456 align 32
 457 acc_idct_colloop1:
 458
 459         movq mm0,   [INP] ;             ; 0 ; x3 x2 x1 x0
 460
 461         movq mm1,   [INP+8] ;   ; 1 ; x7 x6 x5 x4
 462         movq mm2, mm0 ;                         ; 2 ; x3 x2 x1 x0
 463
 464         movq mm3,   [TABLE] ;   ; 3 ; w06 w04 w02 w00
 465         punpcklwd mm0, mm1 ;                    ; x5 x1 x4 x0
 466
 467 ; ----------
 468         movq mm5, mm0 ;                                 ; 5 ; x5 x1 x4 x0
 469         punpckldq mm0, mm0 ;                    ; x4 x0 x4 x0
 470
 471         movq mm4,   [TABLE+8] ; ; 4 ; w07 w05 w03 w01
 472         punpckhwd mm2, mm1 ;                    ; 1 ; x7 x3 x6 x2
 473
 474         pmaddwd mm3, mm0 ;                              ; x4*w06+x0*w04 x4*w02+x0*w00
 475         movq mm6, mm2 ;                         ; 6 ; x7 x3 x6 x2
 476
 477         movq mm1,   [TABLE+32] ;; 1 ; w22 w20 w18 w16
 478         punpckldq mm2, mm2 ;                    ; x6 x2 x6 x2
 479
 480         pmaddwd mm4, mm2 ;                              ; x6*w07+x2*w05 x6*w03+x2*w01
 481         punpckhdq mm5, mm5 ;                    ; x5 x1 x5 x1
 482
 483         pmaddwd mm0,   [TABLE+16] ;; x4*w14+x0*w12 x4*w10+x0*w08
 484         punpckhdq mm6, mm6 ;                    ; x7 x3 x7 x3
 485
 486         movq mm7,   [TABLE+40] ;; 7 ; w23 w21 w19 w17
 487         pmaddwd mm1, mm5 ;                              ; x5*w22+x1*w20 x5*w18+x1*w16
 488
 489         paddd mm3,   [round_inv_col] ;; +rounder
 490         pmaddwd mm7, mm6 ;                              ; x7*w23+x3*w21 x7*w19+x3*w17
 491
 492         pmaddwd mm2,   [TABLE+24] ;; x6*w15+x2*w13 x6*w11+x2*w09
 493         paddd mm3, mm4 ;                                ; 4 ; a1=sum(even1) a0=sum(even0)
 494
 495         pmaddwd mm5,   [TABLE+48] ;; x5*w30+x1*w28 x5*w26+x1*w24
 496         movq mm4, mm3 ;                         ; 4 ; a1 a0
 497
 498         pmaddwd mm6,   [TABLE+56] ;; x7*w31+x3*w29 x7*w27+x3*w25
 499         paddd mm1, mm7 ;                                ; 7 ; b1=sum(odd1) b0=sum(odd0)
 500
 501         paddd mm0,   [round_inv_col] ;; +rounder
 502         psubd mm3, mm1 ;                                ; a1-b1 a0-b0
 503
 504         psrad mm3, SHIFT_INV_COL;               ; y6=a1-b1 y7=a0-b0
 505         paddd mm1, mm4 ;                                ; 4 ; a1+b1 a0+b0
 506
 507         paddd mm0, mm2 ;                                ; 2 ; a3=sum(even3) a2=sum(even2)
 508         psrad mm1, SHIFT_INV_COL;               ; y1=a1+b1 y0=a0+b0
 509
 510         paddd mm5, mm6 ;                                ; 6 ; b3=sum(odd3) b2=sum(odd2)
 511         movq mm4, mm0 ;                         ; 4 ; a3 a2
 512
 513         paddd mm0, mm5 ;                                ; a3+b3 a2+b2
 514         psubd mm4, mm5 ;                                ; 5 ; a3-b3 a2-b2
 515
 516         add INP, 16;                                    ; increment INPUT pointer -> row 1
 517         psrad mm4, SHIFT_INV_COL;               ; y4=a3-b3 y5=a2-b2
 518
 519         add TABLE, 0;                                   ;  TABLE += 64 -> row 1
 520         psrad mm0, SHIFT_INV_COL;               ; y3=a3+b3 y2=a2+b2
 521
 522 ;       movq mm2,   [INP] ;             ; row+1; 0;  x3 x2 x1 x0
 523         packssdw mm4, mm3 ;                             ; 3 ; y6 y7 y4 y5
 524
 525         packssdw mm1, mm0 ;                             ; 0 ; y3 y2 y1 y0
 526         movq mm7, mm4 ;                         ; 7 ; y6 y7 y4 y5
 527
 528 ;       movq mm0, mm2 ;                                 ; row+1;  2 ; x3 x2 x1 x0
 529 ;       por mm1,   dct_one_corr ;       ; correction y2 +0.5
 530         psrld mm4, 16 ;                                 ; 0 y6 0 y4
 531
 532         movq   [OUT], mm1 ;     ; 1 ; save y3 y2 y1 y0
 533         pslld mm7, 16 ;                                 ; y7 0 y5 0
 534
 535 ;       movq mm1,   [INP+8] ;   ; row+1;  1 ; x7 x6 x5 x4
 536 ;       por mm7,   dct_one_corr ;       ; correction y2 +0.5
 537         por mm7, mm4 ;                                  ; 4 ; y7 y6 y5 y4
 538
 539 ;       movq mm3,   [TABLE] ;   ; 3 ; w06 w04 w02 w00
 540 ;        punpcklwd mm0, mm1 ;                   ; row+1;  x5 x1 x4 x0
 541
 542    ; begin processing row 1
 543         movq   [OUT+8], mm7 ;   ; 7 ; save y7 y6 y5 y4
 544         add edi, 0x01;
 545
 546         add OUT, 16;
 547         cmp edi, 0x08;  ; compare x <> 8
 548
 549         jl near  acc_idct_colloop1;     ; end for ( x = 0; x < 8; ++x )
 550
 551         ; done with the iDCT column-transformation
 552
 553                 ; now we have to transpose the output 8x8 matrix
 554                 ; 8x8 (OUT) -> 8x8't' (IN)
 555
 556                 ; the transposition is implemented as 4 sub-operations.
 557         ; 1) transpose upper-left quad
 558         ; 2) transpose lower-right quad
 559         ; 3) transpose lower-left quad
 560         ; 4) transpose upper-right quad
 561
 562
 563
 564         ; mm0 = 1st row [ A B C D ] row1
 565         ; mm1 = 2nd row [ E F G H ] 2
 566         ; mm2 = 3rd row [ I J K L ] 3
 567         ; mm3 = 4th row [ M N O P ] 4
 568
 569         ; 1) transpose upper-left quad
 570 ;       lea OUT,   [qwTemp];
 571         mov OUT,    [ebp+12];
 572
 573         movq mm0,   [OUT + ROW_STRIDE * 0 ]
 574
 575         movq mm1,   [OUT + ROW_STRIDE * 1 ]
 576         movq mm4, mm0;  ; mm4 = copy of row1[A B C D]
 577
 578         movq mm2,   [OUT + ROW_STRIDE * 2 ]
 579         punpcklwd mm0, mm1; ; mm0 = [ 0 4 1 5]
 580
 581         movq mm3,   [OUT + ROW_STRIDE * 3]
 582         punpckhwd mm4, mm1 ; mm4 = [ 2 6 3 7]
 583
 584         movq mm6, mm2
 585         punpcklwd mm2, mm3      ; mm2 = [ 8 12 9 13]
 586
 587         punpckhwd mm6, mm3      ; mm6 = 10 14 11 15]
 588         movq mm1, mm0   ; mm1 = [ 0 4 1 5]
 589
 590         mov INP,   [ebp+8]      ; load input address
 591         punpckldq mm0, mm2      ; final result mm0 = row1 [0 4 8 12]
 592
 593         movq mm3, mm4;  ; mm3 = [ 2 6 3 7]
 594         punpckhdq mm1, mm2; ; mm1 = final result mm1 = row2 [1 5 9 13]
 595
 596         movq   [ INP + ROW_STRIDE * 0 ], mm0; ; store row 1
 597         punpckldq mm4, mm6; ; final result mm4 = row3 [2 6 10 14]
 598
 599 ; begin reading next quadrant (lower-right)
 600         movq mm0,   [OUT + ROW_STRIDE*4 + 8];
 601         punpckhdq mm3, mm6; ; final result mm3 = row4 [3 7 11 15]
 602
 603         movq   [ INP +ROW_STRIDE * 2], mm4; ; store row 3
 604         movq mm4, mm0;  ; mm4 = copy of row1[A B C D]
 605
 606         movq   [ INP +ROW_STRIDE * 1], mm1; ; store row 2
 607
 608         movq mm1,   [OUT + ROW_STRIDE*5 + 8]
 609
 610         movq   [ INP +ROW_STRIDE * 3], mm3; ; store row 4
 611         punpcklwd mm0, mm1; ; mm0 = [ 0 4 1 5]
 612
 613         ; 2) transpose lower-right quadrant
 614
 615 ;       movq mm0,   [OUT + ROW_STRIDE*4 + 8]
 616
 617 ;       movq mm1,   [OUT + ROW_STRIDE*5 + 8]
 618 ;        movq mm4, mm0; ; mm4 = copy of row1[A B C D]
 619
 620         movq mm2,   [OUT + ROW_STRIDE*6 + 8]
 621 ;        punpcklwd mm0, mm1; ; mm0 = [ 0 4 1 5]
 622          punpckhwd mm4, mm1; ; mm4 = [ 2 6 3 7]
 623
 624         movq mm3,   [OUT + ROW_STRIDE*7 + 8]
 625         movq mm6, mm2;
 626
 627         punpcklwd mm2, mm3;     ; mm2 = [ 8 12 9 13]
 628         movq mm1, mm0;  ; mm1 = [ 0 4 1 5]
 629
 630         punpckhwd mm6, mm3;     ; mm6 = 10 14 11 15]
 631         movq mm3, mm4;  ; mm3 = [ 2 6 3 7]
 632
 633         punpckldq mm0, mm2;     ; final result mm0 = row1 [0 4 8 12]
 634
 635         punpckhdq mm1, mm2; ; mm1 = final result mm1 = row2 [1 5 9 13]
 636         ; ;  slot
 637
 638         movq   [ INP + ROW_STRIDE*4 + 8], mm0; ; store row 1
 639         punpckldq mm4, mm6; ; final result mm4 = row3 [2 6 10 14]
 640
 641         movq mm0,   [OUT + ROW_STRIDE * 4 ]
 642         punpckhdq mm3, mm6; ; final result mm3 = row4 [3 7 11 15]
 643         movq   [ INP +ROW_STRIDE*6 + 8], mm4; ; store row 3
 644         movq mm4, mm0;  ; mm4 = copy of row1[A B C D]
 645
 646         movq   [ INP +ROW_STRIDE*5 + 8], mm1; ; store row 2
 647          ; ;  slot
 648         movq mm1,   [OUT + ROW_STRIDE * 5 ]
 649          ; ;  slot
 650
 651         movq   [ INP +ROW_STRIDE*7 + 8], mm3; ; store row 4
 652         punpcklwd mm0, mm1; ; mm0 = [ 0 4 1 5]
 653
 654   ; 3) transpose lower-left
 655 ;       movq mm0,   [OUT + ROW_STRIDE * 4 ]
 656
 657 ;       movq mm1,   [OUT + ROW_STRIDE * 5 ]
 658 ;        movq mm4, mm0; ; mm4 = copy of row1[A B C D]
 659
 660         movq mm2,   [OUT + ROW_STRIDE * 6 ]
 661 ;        punpcklwd mm0, mm1; ; mm0 = [ 0 4 1 5]
 662         punpckhwd mm4, mm1; ; mm4 = [ 2 6 3 7]
 663
 664         movq mm3,   [OUT + ROW_STRIDE * 7 ]
 665         movq mm6, mm2;
 666
 667         punpcklwd mm2, mm3;     ; mm2 = [ 8 12 9 13]
 668         movq mm1, mm0;  ; mm1 = [ 0 4 1 5]
 669
 670         punpckhwd mm6, mm3;     ; mm6 = 10 14 11 15]
 671         movq mm3, mm4;  ; mm3 = [ 2 6 3 7]
 672
 673         punpckldq mm0, mm2;     ; final result mm0 = row1 [0 4 8 12]
 674
 675         punpckhdq mm1, mm2; ; mm1 = final result mm1 = row2 [1 5 9 13]
 676          ; ; slot
 677
 678         movq   [ INP + ROW_STRIDE * 0 + 8 ], mm0; ; store row 1
 679         punpckldq mm4, mm6; ; final result mm4 = row3 [2 6 10 14]
 680
 681 ; begin reading next quadrant (upper-right)
 682         movq mm0,   [OUT + ROW_STRIDE*0 + 8];
 683         punpckhdq mm3, mm6; ; final result mm3 = row4 [3 7 11 15]
 684
 685         movq   [ INP +ROW_STRIDE * 2 + 8], mm4; ; store row 3
 686         movq mm4, mm0;  ; mm4 = copy of row1[A B C D]
 687
 688         movq   [ INP +ROW_STRIDE * 1 + 8 ], mm1; ; store row 2
 689         movq mm1,   [OUT + ROW_STRIDE*1 + 8]
 690
 691         movq   [ INP +ROW_STRIDE * 3 + 8], mm3; ; store row 4
 692         punpcklwd mm0, mm1; ; mm0 = [ 0 4 1 5]
 693
 694
 695         ; 2) transpose lower-right quadrant
 696
 697 ;       movq mm0,   [OUT + ROW_STRIDE*4 + 8]
 698
 699 ;       movq mm1,   [OUT + ROW_STRIDE*5 + 8]
 700 ;        movq mm4, mm0; ; mm4 = copy of row1[A B C D]
 701
 702         movq mm2,   [OUT + ROW_STRIDE*2 + 8]
 703 ;        punpcklwd mm0, mm1; ; mm0 = [ 0 4 1 5]
 704         punpckhwd mm4, mm1; ; mm4 = [ 2 6 3 7]
 705
 706         movq mm3,   [OUT + ROW_STRIDE*3 + 8]
 707         movq mm6, mm2;
 708
 709         punpcklwd mm2, mm3;     ; mm2 = [ 8 12 9 13]
 710         movq mm1, mm0;  ; mm1 = [ 0 4 1 5]
 711
 712         punpckhwd mm6, mm3;     ; mm6 = 10 14 11 15]
 713         movq mm3, mm4;  ; mm3 = [ 2 6 3 7]
 714
 715         punpckldq mm0, mm2;     ; final result mm0 = row1 [0 4 8 12]
 716
 717         punpckhdq mm1, mm2; ; mm1 = final result mm1 = row2 [1 5 9 13]
 718         ; ;  slot
 719
 720         movq  [ INP + ROW_STRIDE*4 ], mm0; ; store row 1
 721         punpckldq mm4, mm6; ; final result mm4 = row3 [2 6 10 14]
 722
 723         movq  [ INP +ROW_STRIDE*5 ], mm1; ; store row 2
 724         punpckhdq mm3, mm6; ; final result mm3 = row4 [3 7 11 15]
 725
 726         movq  [ INP +ROW_STRIDE*6 ], mm4; ; store row 3
 727          ; ;  slot
 728
 729         movq  [ INP +ROW_STRIDE*7 ], mm3; ; store row 4
 730
 731         pop edi
 732         pop edx
 733         pop ecx
 734         pop ebx
 735
 736         pop ebp                 ; restore frame pointer
 737
 738         emms
 739         ret