vp8/common/extend.c

   1 /*
   2  *  Copyright (c) 2010 The VP8 project authors. All Rights Reserved.
   3  *
   4  *  Use of this source code is governed by a BSD-style license and patent
   5  *  grant that can be found in the LICENSE file in the root of the source
   6  *  tree. All contributing project authors may be found in the AUTHORS
   7  *  file in the root of the source tree.
   8  */
   9
  10
  11 #include "extend.h"
  12 #include "vpx_mem/vpx_mem.h"
  13
  14
  15 static void extend_plane_borders
  16 (
  17     unsigned char *s, // source
  18     int sp,           // pitch
  19     int h,            // height
  20     int w,            // width
  21     int et,           // extend top border
  22     int el,           // extend left border
  23     int eb,           // extend bottom border
  24     int er            // extend right border
  25 )
  26 {
  27
  28     int i;
  29     unsigned char *src_ptr1, *src_ptr2;
  30     unsigned char *dest_ptr1, *dest_ptr2;
  31     int linesize;
  32
  33     // copy the left and right most columns out
  34     src_ptr1 = s;
  35     src_ptr2 = s + w - 1;
  36     dest_ptr1 = s - el;
  37     dest_ptr2 = s + w;
  38
  39     for (i = 0; i < h - 0 + 1; i++)
  40     {
  41         vpx_memset(dest_ptr1, src_ptr1[0], el);
  42         vpx_memset(dest_ptr2, src_ptr2[0], er);
  43         src_ptr1  += sp;
  44         src_ptr2  += sp;
  45         dest_ptr1 += sp;
  46         dest_ptr2 += sp;
  47     }
  48
  49     // Now copy the top and bottom source lines into each line of the respective borders
  50     src_ptr1 = s - el;
  51     src_ptr2 = s + sp * (h - 1) - el;
  52     dest_ptr1 = s + sp * (-et) - el;
  53     dest_ptr2 = s + sp * (h) - el;
  54     linesize = el + er + w + 1;
  55
  56     for (i = 0; i < (int)et; i++)
  57     {
  58         vpx_memcpy(dest_ptr1, src_ptr1, linesize);
  59         dest_ptr1 += sp;
  60     }
  61
  62     for (i = 0; i < (int)eb; i++)
  63     {
  64         vpx_memcpy(dest_ptr2, src_ptr2, linesize);
  65         dest_ptr2 += sp;
  66     }
  67 }
  68
  69
  70 void vp8_extend_to_multiple_of16(YV12_BUFFER_CONFIG *ybf, int width, int height)
  71 {
  72     int er = 0xf & (16 - (width & 0xf));
  73     int eb = 0xf & (16 - (height & 0xf));
  74
  75     // check for non multiples of 16
  76     if (er != 0 || eb != 0)
  77     {
  78         extend_plane_borders(ybf->y_buffer, ybf->y_stride, height, width, 0, 0, eb, er);
  79
  80         //adjust for uv
  81         height = (height + 1) >> 1;
  82         width  = (width  + 1) >> 1;
  83         er = 0x7 & (8 - (width  & 0x7));
  84         eb = 0x7 & (8 - (height & 0x7));
  85
  86         if (er || eb)
  87         {
  88             extend_plane_borders(ybf->u_buffer, ybf->uv_stride, height, width, 0, 0, eb, er);
  89             extend_plane_borders(ybf->v_buffer, ybf->uv_stride, height, width, 0, 0, eb, er);
  90         }
  91     }
  92 }
  93
  94 // note the extension is only for the last row, for intra prediction purpose
  95 void vp8_extend_mb_row(YV12_BUFFER_CONFIG *ybf, unsigned char *YPtr, unsigned char *UPtr, unsigned char *VPtr)
  96 {
  97     int i;
  98
  99     YPtr += ybf->y_stride * 14;
 100     UPtr += ybf->uv_stride * 6;
 101     VPtr += ybf->uv_stride * 6;
 102
 103     for (i = 0; i < 4; i++)
 104     {
 105         YPtr[i] = YPtr[-1];
 106         UPtr[i] = UPtr[-1];
 107         VPtr[i] = VPtr[-1];
 108     }
 109
 110     YPtr += ybf->y_stride;
 111     UPtr += ybf->uv_stride;
 112     VPtr += ybf->uv_stride;
 113
 114     for (i = 0; i < 4; i++)
 115     {
 116         YPtr[i] = YPtr[-1];
 117         UPtr[i] = UPtr[-1];
 118         VPtr[i] = VPtr[-1];
 119     }
 120 }