media/libvpx/vpx_scale/generic/yv12extend.c

Thu, 15 Jan 2015 15:59:08 +0100

author
Michael Schloh von Bennewitz <michael@schloh.com>
date
Thu, 15 Jan 2015 15:59:08 +0100
branch
TOR_BUG_9701
changeset 10
ac0c01689b40
permissions
-rw-r--r--

Implement a real Private Browsing Mode condition by changing the API/ABI;
This solves Tor bug #9701, complying with disk avoidance documented in
https://www.torproject.org/projects/torbrowser/design/#disk-avoidance.

     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  */
    11 #include <assert.h>
    12 #include "./vpx_config.h"
    13 #include "vpx/vpx_integer.h"
    14 #include "vpx_mem/vpx_mem.h"
    15 #include "vpx_scale/yv12config.h"
    17 static void extend_plane(uint8_t *const src, int src_stride,
    18                          int width, int height,
    19                          int extend_top, int extend_left,
    20                          int extend_bottom, int extend_right) {
    21   int i;
    22   const int linesize = extend_left + extend_right + width;
    24   /* copy the left and right most columns out */
    25   uint8_t *src_ptr1 = src;
    26   uint8_t *src_ptr2 = src + width - 1;
    27   uint8_t *dst_ptr1 = src - extend_left;
    28   uint8_t *dst_ptr2 = src + width;
    30   for (i = 0; i < height; ++i) {
    31     vpx_memset(dst_ptr1, src_ptr1[0], extend_left);
    32     vpx_memset(dst_ptr2, src_ptr2[0], extend_right);
    33     src_ptr1 += src_stride;
    34     src_ptr2 += src_stride;
    35     dst_ptr1 += src_stride;
    36     dst_ptr2 += src_stride;
    37   }
    39   /* Now copy the top and bottom lines into each line of the respective
    40    * borders
    41    */
    42   src_ptr1 = src - extend_left;
    43   src_ptr2 = src + src_stride * (height - 1) - extend_left;
    44   dst_ptr1 = src + src_stride * -extend_top - extend_left;
    45   dst_ptr2 = src + src_stride * height - extend_left;
    47   for (i = 0; i < extend_top; ++i) {
    48     vpx_memcpy(dst_ptr1, src_ptr1, linesize);
    49     dst_ptr1 += src_stride;
    50   }
    52   for (i = 0; i < extend_bottom; ++i) {
    53     vpx_memcpy(dst_ptr2, src_ptr2, linesize);
    54     dst_ptr2 += src_stride;
    55   }
    56 }
    58 void vp8_yv12_extend_frame_borders_c(YV12_BUFFER_CONFIG *ybf) {
    59   assert(ybf->y_height - ybf->y_crop_height < 16);
    60   assert(ybf->y_width - ybf->y_crop_width < 16);
    61   assert(ybf->y_height - ybf->y_crop_height >= 0);
    62   assert(ybf->y_width - ybf->y_crop_width >= 0);
    64   extend_plane(ybf->y_buffer, ybf->y_stride,
    65                ybf->y_crop_width, ybf->y_crop_height,
    66                ybf->border, ybf->border,
    67                ybf->border + ybf->y_height - ybf->y_crop_height,
    68                ybf->border + ybf->y_width - ybf->y_crop_width);
    70   extend_plane(ybf->u_buffer, ybf->uv_stride,
    71                (ybf->y_crop_width + 1) / 2, (ybf->y_crop_height + 1) / 2,
    72                ybf->border / 2, ybf->border / 2,
    73                (ybf->border + ybf->y_height - ybf->y_crop_height + 1) / 2,
    74                (ybf->border + ybf->y_width - ybf->y_crop_width + 1) / 2);
    76   extend_plane(ybf->v_buffer, ybf->uv_stride,
    77                (ybf->y_crop_width + 1) / 2, (ybf->y_crop_height + 1) / 2,
    78                ybf->border / 2, ybf->border / 2,
    79                (ybf->border + ybf->y_height - ybf->y_crop_height + 1) / 2,
    80                (ybf->border + ybf->y_width - ybf->y_crop_width + 1) / 2);
    81 }
    83 #if CONFIG_VP9
    84 static void extend_frame(YV12_BUFFER_CONFIG *const ybf,
    85                          int subsampling_x, int subsampling_y,
    86                          int ext_size) {
    87   const int c_w = ybf->uv_crop_width;
    88   const int c_h = ybf->uv_crop_height;
    89   const int c_ext_size = ext_size >> 1;
    90   const int c_et = c_ext_size;
    91   const int c_el = c_ext_size;
    92   const int c_eb = c_ext_size + ybf->uv_height - ybf->uv_crop_height;
    93   const int c_er = c_ext_size + ybf->uv_width - ybf->uv_crop_width;
    95   assert(ybf->y_height - ybf->y_crop_height < 16);
    96   assert(ybf->y_width - ybf->y_crop_width < 16);
    97   assert(ybf->y_height - ybf->y_crop_height >= 0);
    98   assert(ybf->y_width - ybf->y_crop_width >= 0);
   100   extend_plane(ybf->y_buffer, ybf->y_stride,
   101                ybf->y_crop_width, ybf->y_crop_height,
   102                ext_size, ext_size,
   103                ext_size + ybf->y_height - ybf->y_crop_height,
   104                ext_size + ybf->y_width - ybf->y_crop_width);
   106   extend_plane(ybf->u_buffer, ybf->uv_stride,
   107                c_w, c_h, c_et, c_el, c_eb, c_er);
   109   extend_plane(ybf->v_buffer, ybf->uv_stride,
   110                c_w, c_h, c_et, c_el, c_eb, c_er);
   111 }
   113 void vp9_extend_frame_borders_c(YV12_BUFFER_CONFIG *ybf,
   114                                 int subsampling_x, int subsampling_y) {
   115   extend_frame(ybf, subsampling_x, subsampling_y, ybf->border);
   116 }
   118 void vp9_extend_frame_inner_borders_c(YV12_BUFFER_CONFIG *ybf,
   119                                       int subsampling_x, int subsampling_y) {
   120   const int inner_bw = (ybf->border > VP9INNERBORDERINPIXELS) ?
   121                        VP9INNERBORDERINPIXELS : ybf->border;
   122   extend_frame(ybf, subsampling_x, subsampling_y, inner_bw);
   123 }
   124 #endif  // CONFIG_VP9
   126 // Copies the source image into the destination image and updates the
   127 // destination's UMV borders.
   128 // Note: The frames are assumed to be identical in size.
   129 void vp8_yv12_copy_frame_c(const YV12_BUFFER_CONFIG *src_ybc,
   130                            YV12_BUFFER_CONFIG *dst_ybc) {
   131   int row;
   132   const uint8_t *src = src_ybc->y_buffer;
   133   uint8_t *dst = dst_ybc->y_buffer;
   135 #if 0
   136   /* These assertions are valid in the codec, but the libvpx-tester uses
   137    * this code slightly differently.
   138    */
   139   assert(src_ybc->y_width == dst_ybc->y_width);
   140   assert(src_ybc->y_height == dst_ybc->y_height);
   141 #endif
   143   for (row = 0; row < src_ybc->y_height; ++row) {
   144     vpx_memcpy(dst, src, src_ybc->y_width);
   145     src += src_ybc->y_stride;
   146     dst += dst_ybc->y_stride;
   147   }
   149   src = src_ybc->u_buffer;
   150   dst = dst_ybc->u_buffer;
   152   for (row = 0; row < src_ybc->uv_height; ++row) {
   153     vpx_memcpy(dst, src, src_ybc->uv_width);
   154     src += src_ybc->uv_stride;
   155     dst += dst_ybc->uv_stride;
   156   }
   158   src = src_ybc->v_buffer;
   159   dst = dst_ybc->v_buffer;
   161   for (row = 0; row < src_ybc->uv_height; ++row) {
   162     vpx_memcpy(dst, src, src_ybc->uv_width);
   163     src += src_ybc->uv_stride;
   164     dst += dst_ybc->uv_stride;
   165   }
   167   vp8_yv12_extend_frame_borders_c(dst_ybc);
   168 }
   170 void vpx_yv12_copy_y_c(const YV12_BUFFER_CONFIG *src_ybc,
   171                        YV12_BUFFER_CONFIG *dst_ybc) {
   172   int row;
   173   const uint8_t *src = src_ybc->y_buffer;
   174   uint8_t *dst = dst_ybc->y_buffer;
   176   for (row = 0; row < src_ybc->y_height; ++row) {
   177     vpx_memcpy(dst, src, src_ybc->y_width);
   178     src += src_ybc->y_stride;
   179     dst += dst_ybc->y_stride;
   180   }
   181 }

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