vp8/common/extend.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 "extend.h"
  13 #include "vpx_mem/vpx_mem.h"
  14
  15
  16 static void extend_plane_borders
  17 (
  18     unsigned char *s, /* source */
  19     int sp,           /* pitch */
  20     int h,            /* height */
  21     int w,            /* width */
  22     int et,           /* extend top border */
  23     int el,           /* extend left border */
  24     int eb,           /* extend bottom border */
  25     int er            /* extend right border */
  26 )
  27 {
  28
  29     int i;
  30     unsigned char *src_ptr1, *src_ptr2;
  31     unsigned char *dest_ptr1, *dest_ptr2;
  32     int linesize;
  33
  34     /* copy the left and right most columns out */
  35     src_ptr1 = s;
  36     src_ptr2 = s + w - 1;
  37     dest_ptr1 = s - el;
  38     dest_ptr2 = s + w;
  39
  40     for (i = 0; i < h - 0 + 1; i++)
  41     {
  42         /* Some linkers will complain if we call vpx_memset with el set to a
  43          * constant 0.
  44          */
  45         if (el)
  46             vpx_memset(dest_ptr1, src_ptr1[0], el);
  47         vpx_memset(dest_ptr2, src_ptr2[0], er);
  48         src_ptr1  += sp;
  49         src_ptr2  += sp;
  50         dest_ptr1 += sp;
  51         dest_ptr2 += sp;
  52     }
  53
  54     /* Now copy the top and bottom source lines into each line of the respective borders */
  55     src_ptr1 = s - el;
  56     src_ptr2 = s + sp * (h - 1) - el;
  57     dest_ptr1 = s + sp * (-et) - el;
  58     dest_ptr2 = s + sp * (h) - el;
  59     linesize = el + er + w + 1;
  60
  61     for (i = 0; i < (int)et; i++)
  62     {
  63         vpx_memcpy(dest_ptr1, src_ptr1, linesize);
  64         dest_ptr1 += sp;
  65     }
  66
  67     for (i = 0; i < (int)eb; i++)
  68     {
  69         vpx_memcpy(dest_ptr2, src_ptr2, linesize);
  70         dest_ptr2 += sp;
  71     }
  72 }
  73
  74
  75 void vp8_extend_to_multiple_of16(YV12_BUFFER_CONFIG *ybf, int width, int height)
  76 {
  77     int er = 0xf & (16 - (width & 0xf));
  78     int eb = 0xf & (16 - (height & 0xf));
  79
  80     /* check for non multiples of 16 */
  81     if (er != 0 || eb != 0)
  82     {
  83         extend_plane_borders(ybf->y_buffer, ybf->y_stride, height, width, 0, 0, eb, er);
  84
  85         /* adjust for uv */
  86         height = (height + 1) >> 1;
  87         width  = (width  + 1) >> 1;
  88         er = 0x7 & (8 - (width  & 0x7));
  89         eb = 0x7 & (8 - (height & 0x7));
  90
  91         if (er || eb)
  92         {
  93             extend_plane_borders(ybf->u_buffer, ybf->uv_stride, height, width, 0, 0, eb, er);
  94             extend_plane_borders(ybf->v_buffer, ybf->uv_stride, height, width, 0, 0, eb, er);
  95         }
  96     }
  97 }
  98
  99 /* note the extension is only for the last row, for intra prediction purpose */
 100 void vp8_extend_mb_row(YV12_BUFFER_CONFIG *ybf, unsigned char *YPtr, unsigned char *UPtr, unsigned char *VPtr)
 101 {
 102     int i;
 103
 104     YPtr += ybf->y_stride * 14;
 105     UPtr += ybf->uv_stride * 6;
 106     VPtr += ybf->uv_stride * 6;
 107
 108     for (i = 0; i < 4; i++)
 109     {
 110         YPtr[i] = YPtr[-1];
 111         UPtr[i] = UPtr[-1];
 112         VPtr[i] = VPtr[-1];
 113     }
 114
 115     YPtr += ybf->y_stride;
 116     UPtr += ybf->uv_stride;
 117     VPtr += ybf->uv_stride;
 118
 119     for (i = 0; i < 4; i++)
 120     {
 121         YPtr[i] = YPtr[-1];
 122         UPtr[i] = UPtr[-1];
 123         VPtr[i] = VPtr[-1];
 124     }
 125 }