libavcodec/ps2/mpegvideo_mmi.c

   1 /*
   2  * Copyright (c) 2000,2001 Fabrice Bellard.
   3  *
   4  * MMI optimization by Leon van Stuivenberg
   5  *
   6  * This file is part of FFmpeg.
   7  *
   8  * FFmpeg is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU Lesser General Public
  10  * License as published by the Free Software Foundation; either
  11  * version 2.1 of the License, or (at your option) any later version.
  12  *
  13  * FFmpeg is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16  * Lesser General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU Lesser General Public
  19  * License along with FFmpeg; if not, write to the Free Software
  20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  21  */
  22
  23 #include "libavcodec/avcodec.h"
  24 #include "libavcodec/dsputil.h"
  25 #include "libavcodec/mpegvideo.h"
  26
  27 static void dct_unquantize_h263_mmi(MpegEncContext *s,
  28                                   DCTELEM *block, int n, int qscale)
  29 {
  30     int level=0, qmul, qadd;
  31     int nCoeffs;
  32
  33     assert(s->block_last_index[n]>=0);
  34
  35     qadd = (qscale - 1) | 1;
  36     qmul = qscale << 1;
  37
  38     if (s->mb_intra) {
  39         if (!s->h263_aic) {
  40             if (n < 4)
  41                 level = block[0] * s->y_dc_scale;
  42             else
  43                 level = block[0] * s->c_dc_scale;
  44         }else {
  45             qadd = 0;
  46             level = block[0];
  47         }
  48         nCoeffs= 63; //does not always use zigzag table
  49     } else {
  50         nCoeffs= s->intra_scantable.raster_end[ s->block_last_index[n] ];
  51     }
  52
  53     asm volatile(
  54         "add    $14, $0, %3     \n\t"
  55         "pcpyld $8, %0, %0      \n\t"
  56         "pcpyh  $8, $8          \n\t"   //r8 = qmul
  57         "pcpyld $9, %1, %1      \n\t"
  58         "pcpyh  $9, $9          \n\t"   //r9 = qadd
  59         ".p2align 2             \n\t"
  60         "1:                     \n\t"
  61         "lq     $10, 0($14)     \n\t"   //r10 = level
  62         "addi   $14, $14, 16    \n\t"   //block+=8
  63         "addi   %2, %2, -8      \n\t"
  64         "pcgth  $11, $0, $10    \n\t"   //r11 = level < 0 ? -1 : 0
  65         "pcgth  $12, $10, $0    \n\t"   //r12 = level > 0 ? -1 : 0
  66         "por    $12, $11, $12   \n\t"
  67         "pmulth $10, $10, $8    \n\t"
  68         "paddh  $13, $9, $11    \n\t"
  69         "pxor   $13, $13, $11   \n\t"   //r13 = level < 0 ? -qadd : qadd
  70         "pmfhl.uw $11           \n\t"
  71         "pinteh $10, $11, $10   \n\t"   //r10 = level * qmul
  72         "paddh  $10, $10, $13   \n\t"
  73         "pand   $10, $10, $12   \n\t"
  74         "sq     $10, -16($14)   \n\t"
  75         "bgez   %2, 1b          \n\t"
  76         :: "r"(qmul), "r" (qadd), "r" (nCoeffs), "r" (block) : "$8", "$9", "$10", "$11", "$12", "$13", "$14", "memory" );
  77
  78     if(s->mb_intra)
  79         block[0]= level;
  80 }
  81
  82
  83 void MPV_common_init_mmi(MpegEncContext *s)
  84 {
  85     s->dct_unquantize_h263_intra =
  86     s->dct_unquantize_h263_inter = dct_unquantize_h263_mmi;
  87 }
  88
  89