vp8/decoder/dequantize.c

   1 /*
   2  *  Copyright (c) 2010 The WebM project authors. All Rights Reserved.
   3  *
   4  *  Use of this source code is governed by a BSD-style license
   5  *  that can be found in the LICENSE file in the root of the source
   6  *  tree. An additional intellectual property rights grant can be found
   7  *  in the file PATENTS.  All contributing project authors may
   8  *  be found in the AUTHORS file in the root of the source tree.
   9  */
  10
  11
  12 #include "vpx_ports/config.h"
  13 #include "dequantize.h"
  14 #include "vp8/common/idct.h"
  15 #include "vpx_mem/vpx_mem.h"
  16
  17 extern void vp8_short_idct4x4llm_c(short *input, short *output, int pitch) ;
  18 extern void vp8_short_idct4x4llm_1_c(short *input, short *output, int pitch);
  19
  20
  21 void vp8_dequantize_b_c(BLOCKD *d)
  22 {
  23     int i;
  24     short *DQ  = d->dqcoeff;
  25     short *Q   = d->qcoeff;
  26     short *DQC = d->dequant;
  27
  28     for (i = 0; i < 16; i++)
  29     {
  30         DQ[i] = Q[i] * DQC[i];
  31     }
  32 }
  33
  34 void vp8_dequant_idct_add_c(short *input, short *dq, unsigned char *pred,
  35                             unsigned char *dest, int pitch, int stride)
  36 {
  37     short output[16];
  38     short *diff_ptr = output;
  39     int r, c;
  40     int i;
  41
  42     for (i = 0; i < 16; i++)
  43     {
  44         input[i] = dq[i] * input[i];
  45     }
  46
  47     /* the idct halves ( >> 1) the pitch */
  48     vp8_short_idct4x4llm_c(input, output, 4 << 1);
  49
  50     vpx_memset(input, 0, 32);
  51
  52     for (r = 0; r < 4; r++)
  53     {
  54         for (c = 0; c < 4; c++)
  55         {
  56             int a = diff_ptr[c] + pred[c];
  57
  58             if (a < 0)
  59                 a = 0;
  60
  61             if (a > 255)
  62                 a = 255;
  63
  64             dest[c] = (unsigned char) a;
  65         }
  66
  67         dest += stride;
  68         diff_ptr += 4;
  69         pred += pitch;
  70     }
  71 }
  72
  73 void vp8_dequant_dc_idct_add_c(short *input, short *dq, unsigned char *pred,
  74                                unsigned char *dest, int pitch, int stride,
  75                                int Dc)
  76 {
  77     int i;
  78     short output[16];
  79     short *diff_ptr = output;
  80     int r, c;
  81
  82     input[0] = (short)Dc;
  83
  84     for (i = 1; i < 16; i++)
  85     {
  86         input[i] = dq[i] * input[i];
  87     }
  88
  89     /* the idct halves ( >> 1) the pitch */
  90     vp8_short_idct4x4llm_c(input, output, 4 << 1);
  91
  92     vpx_memset(input, 0, 32);
  93
  94     for (r = 0; r < 4; r++)
  95     {
  96         for (c = 0; c < 4; c++)
  97         {
  98             int a = diff_ptr[c] + pred[c];
  99
 100             if (a < 0)
 101                 a = 0;
 102
 103             if (a > 255)
 104                 a = 255;
 105
 106             dest[c] = (unsigned char) a;
 107         }
 108
 109         dest += stride;
 110         diff_ptr += 4;
 111         pred += pitch;
 112     }
 113 }