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libavcodec/ps2/mpegvideo_mmi.c

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00001 /*
00002  * Copyright (c) 2000,2001 Fabrice Bellard
00003  *
00004  * MMI optimization by Leon van Stuivenberg
00005  *
00006  * This file is part of FFmpeg.
00007  *
00008  * FFmpeg is free software; you can redistribute it and/or
00009  * modify it under the terms of the GNU Lesser General Public
00010  * License as published by the Free Software Foundation; either
00011  * version 2.1 of the License, or (at your option) any later version.
00012  *
00013  * FFmpeg is distributed in the hope that it will be useful,
00014  * but WITHOUT ANY WARRANTY; without even the implied warranty of
00015  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00016  * Lesser General Public License for more details.
00017  *
00018  * You should have received a copy of the GNU Lesser General Public
00019  * License along with FFmpeg; if not, write to the Free Software
00020  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
00021  */
00022 
00023 #include "libavcodec/avcodec.h"
00024 #include "libavcodec/dsputil.h"
00025 #include "libavcodec/mpegvideo.h"
00026 
00027 static void dct_unquantize_h263_mmi(MpegEncContext *s,
00028                                   DCTELEM *block, int n, int qscale)
00029 {
00030     int level=0, qmul, qadd;
00031     int nCoeffs;
00032 
00033     assert(s->block_last_index[n]>=0);
00034 
00035     qadd = (qscale - 1) | 1;
00036     qmul = qscale << 1;
00037 
00038     if (s->mb_intra) {
00039         if (!s->h263_aic) {
00040             if (n < 4)
00041                 level = block[0] * s->y_dc_scale;
00042             else
00043                 level = block[0] * s->c_dc_scale;
00044         }else {
00045             qadd = 0;
00046             level = block[0];
00047         }
00048         nCoeffs= 63; //does not always use zigzag table
00049     } else {
00050         nCoeffs= s->intra_scantable.raster_end[ s->block_last_index[n] ];
00051     }
00052 
00053     __asm__ volatile(
00054         "add    $14, $0, %3     \n\t"
00055         "pcpyld $8, %0, %0      \n\t"
00056         "pcpyh  $8, $8          \n\t"   //r8 = qmul
00057         "pcpyld $9, %1, %1      \n\t"
00058         "pcpyh  $9, $9          \n\t"   //r9 = qadd
00059         ".p2align 2             \n\t"
00060         "1:                     \n\t"
00061         "lq     $10, 0($14)     \n\t"   //r10 = level
00062         "addi   $14, $14, 16    \n\t"   //block+=8
00063         "addi   %2, %2, -8      \n\t"
00064         "pcgth  $11, $0, $10    \n\t"   //r11 = level < 0 ? -1 : 0
00065         "pcgth  $12, $10, $0    \n\t"   //r12 = level > 0 ? -1 : 0
00066         "por    $12, $11, $12   \n\t"
00067         "pmulth $10, $10, $8    \n\t"
00068         "paddh  $13, $9, $11    \n\t"
00069         "pxor   $13, $13, $11   \n\t"   //r13 = level < 0 ? -qadd : qadd
00070         "pmfhl.uw $11           \n\t"
00071         "pinteh $10, $11, $10   \n\t"   //r10 = level * qmul
00072         "paddh  $10, $10, $13   \n\t"
00073         "pand   $10, $10, $12   \n\t"
00074         "sq     $10, -16($14)   \n\t"
00075         "bgez   %2, 1b          \n\t"
00076         :: "r"(qmul), "r" (qadd), "r" (nCoeffs), "r" (block) : "$8", "$9", "$10", "$11", "$12", "$13", "$14", "memory" );
00077 
00078     if(s->mb_intra)
00079         block[0]= level;
00080 }
00081 
00082 
00083 void MPV_common_init_mmi(MpegEncContext *s)
00084 {
00085     s->dct_unquantize_h263_intra =
00086     s->dct_unquantize_h263_inter = dct_unquantize_h263_mmi;
00087 }
00088 
00089 

Generated on Fri Sep 16 2011 17:17:41 for FFmpeg by  doxygen 1.7.1