media/libvpx/vpx/src/vpx_image.c@ac0c01689b40
media/libvpx/vpx/src/vpx_image.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 */
12 #include <stdlib.h>
13 #include <string.h>
14 #include "vpx/vpx_image.h"
16 #define ADDRESS_STORAGE_SIZE sizeof(size_t)
17 /*returns an addr aligned to the byte boundary specified by align*/
18 #define align_addr(addr,align) (void*)(((size_t)(addr) + ((align) - 1)) & (size_t)-(align))
20 /* Memalign code is copied from vpx_mem.c */
21 static void *img_buf_memalign(size_t align, size_t size) {
22 void *addr,
23 * x = NULL;
25 addr = malloc(size + align - 1 + ADDRESS_STORAGE_SIZE);
27 if (addr) {
28 x = align_addr((unsigned char *)addr + ADDRESS_STORAGE_SIZE, (int)align);
29 /* save the actual malloc address */
30 ((size_t *)x)[-1] = (size_t)addr;
31 }
33 return x;
34 }
36 static void img_buf_free(void *memblk) {
37 if (memblk) {
38 void *addr = (void *)(((size_t *)memblk)[-1]);
39 free(addr);
40 }
41 }
43 static vpx_image_t *img_alloc_helper(vpx_image_t *img,
44 vpx_img_fmt_t fmt,
45 unsigned int d_w,
46 unsigned int d_h,
47 unsigned int buf_align,
48 unsigned int stride_align,
49 unsigned char *img_data) {
51 unsigned int h, w, s, xcs, ycs, bps;
52 int align;
54 /* Treat align==0 like align==1 */
55 if (!buf_align)
56 buf_align = 1;
58 /* Validate alignment (must be power of 2) */
59 if (buf_align & (buf_align - 1))
60 goto fail;
62 /* Treat align==0 like align==1 */
63 if (!stride_align)
64 stride_align = 1;
66 /* Validate alignment (must be power of 2) */
67 if (stride_align & (stride_align - 1))
68 goto fail;
70 /* Get sample size for this format */
71 switch (fmt) {
72 case VPX_IMG_FMT_RGB32:
73 case VPX_IMG_FMT_RGB32_LE:
74 case VPX_IMG_FMT_ARGB:
75 case VPX_IMG_FMT_ARGB_LE:
76 bps = 32;
77 break;
78 case VPX_IMG_FMT_RGB24:
79 case VPX_IMG_FMT_BGR24:
80 bps = 24;
81 break;
82 case VPX_IMG_FMT_RGB565:
83 case VPX_IMG_FMT_RGB565_LE:
84 case VPX_IMG_FMT_RGB555:
85 case VPX_IMG_FMT_RGB555_LE:
86 case VPX_IMG_FMT_UYVY:
87 case VPX_IMG_FMT_YUY2:
88 case VPX_IMG_FMT_YVYU:
89 bps = 16;
90 break;
91 case VPX_IMG_FMT_I420:
92 case VPX_IMG_FMT_YV12:
93 case VPX_IMG_FMT_VPXI420:
94 case VPX_IMG_FMT_VPXYV12:
95 bps = 12;
96 break;
97 default:
98 bps = 16;
99 break;
100 }
102 /* Get chroma shift values for this format */
103 switch (fmt) {
104 case VPX_IMG_FMT_I420:
105 case VPX_IMG_FMT_YV12:
106 case VPX_IMG_FMT_VPXI420:
107 case VPX_IMG_FMT_VPXYV12:
108 xcs = 1;
109 break;
110 default:
111 xcs = 0;
112 break;
113 }
115 switch (fmt) {
116 case VPX_IMG_FMT_I420:
117 case VPX_IMG_FMT_YV12:
118 case VPX_IMG_FMT_VPXI420:
119 case VPX_IMG_FMT_VPXYV12:
120 ycs = 1;
121 break;
122 default:
123 ycs = 0;
124 break;
125 }
127 /* Calculate storage sizes given the chroma subsampling */
128 align = (1 << xcs) - 1;
129 w = (d_w + align) & ~align;
130 align = (1 << ycs) - 1;
131 h = (d_h + align) & ~align;
132 s = (fmt & VPX_IMG_FMT_PLANAR) ? w : bps * w / 8;
133 s = (s + stride_align - 1) & ~(stride_align - 1);
135 /* Allocate the new image */
136 if (!img) {
137 img = (vpx_image_t *)calloc(1, sizeof(vpx_image_t));
139 if (!img)
140 goto fail;
142 img->self_allocd = 1;
143 } else {
144 memset(img, 0, sizeof(vpx_image_t));
145 }
147 img->img_data = img_data;
149 if (!img_data) {
150 img->img_data = img_buf_memalign(buf_align, ((fmt & VPX_IMG_FMT_PLANAR) ?
151 h * s * bps / 8 : h * s));
152 img->img_data_owner = 1;
153 }
155 if (!img->img_data)
156 goto fail;
158 img->fmt = fmt;
159 img->w = w;
160 img->h = h;
161 img->x_chroma_shift = xcs;
162 img->y_chroma_shift = ycs;
163 img->bps = bps;
165 /* Calculate strides */
166 img->stride[VPX_PLANE_Y] = img->stride[VPX_PLANE_ALPHA] = s;
167 img->stride[VPX_PLANE_U] = img->stride[VPX_PLANE_V] = s >> xcs;
169 /* Default viewport to entire image */
170 if (!vpx_img_set_rect(img, 0, 0, d_w, d_h))
171 return img;
173 fail:
174 vpx_img_free(img);
175 return NULL;
176 }
178 vpx_image_t *vpx_img_alloc(vpx_image_t *img,
179 vpx_img_fmt_t fmt,
180 unsigned int d_w,
181 unsigned int d_h,
182 unsigned int align) {
183 return img_alloc_helper(img, fmt, d_w, d_h, align, align, NULL);
184 }
186 vpx_image_t *vpx_img_wrap(vpx_image_t *img,
187 vpx_img_fmt_t fmt,
188 unsigned int d_w,
189 unsigned int d_h,
190 unsigned int stride_align,
191 unsigned char *img_data) {
192 /* By setting buf_align = 1, we don't change buffer alignment in this
193 * function. */
194 return img_alloc_helper(img, fmt, d_w, d_h, 1, stride_align, img_data);
195 }
197 int vpx_img_set_rect(vpx_image_t *img,
198 unsigned int x,
199 unsigned int y,
200 unsigned int w,
201 unsigned int h) {
202 unsigned char *data;
204 if (x + w <= img->w && y + h <= img->h) {
205 img->d_w = w;
206 img->d_h = h;
208 /* Calculate plane pointers */
209 if (!(img->fmt & VPX_IMG_FMT_PLANAR)) {
210 img->planes[VPX_PLANE_PACKED] =
211 img->img_data + x * img->bps / 8 + y * img->stride[VPX_PLANE_PACKED];
212 } else {
213 data = img->img_data;
215 if (img->fmt & VPX_IMG_FMT_HAS_ALPHA) {
216 img->planes[VPX_PLANE_ALPHA] =
217 data + x + y * img->stride[VPX_PLANE_ALPHA];
218 data += img->h * img->stride[VPX_PLANE_ALPHA];
219 }
221 img->planes[VPX_PLANE_Y] = data + x + y * img->stride[VPX_PLANE_Y];
222 data += img->h * img->stride[VPX_PLANE_Y];
224 if (!(img->fmt & VPX_IMG_FMT_UV_FLIP)) {
225 img->planes[VPX_PLANE_U] = data
226 + (x >> img->x_chroma_shift)
227 + (y >> img->y_chroma_shift) * img->stride[VPX_PLANE_U];
228 data += (img->h >> img->y_chroma_shift) * img->stride[VPX_PLANE_U];
229 img->planes[VPX_PLANE_V] = data
230 + (x >> img->x_chroma_shift)
231 + (y >> img->y_chroma_shift) * img->stride[VPX_PLANE_V];
232 } else {
233 img->planes[VPX_PLANE_V] = data
234 + (x >> img->x_chroma_shift)
235 + (y >> img->y_chroma_shift) * img->stride[VPX_PLANE_V];
236 data += (img->h >> img->y_chroma_shift) * img->stride[VPX_PLANE_V];
237 img->planes[VPX_PLANE_U] = data
238 + (x >> img->x_chroma_shift)
239 + (y >> img->y_chroma_shift) * img->stride[VPX_PLANE_U];
240 }
241 }
243 return 0;
244 }
246 return -1;
247 }
249 void vpx_img_flip(vpx_image_t *img) {
250 /* Note: In the calculation pointer adjustment calculation, we want the
251 * rhs to be promoted to a signed type. Section 6.3.1.8 of the ISO C99
252 * standard indicates that if the adjustment parameter is unsigned, the
253 * stride parameter will be promoted to unsigned, causing errors when
254 * the lhs is a larger type than the rhs.
255 */
256 img->planes[VPX_PLANE_Y] += (signed)(img->d_h - 1) * img->stride[VPX_PLANE_Y];
257 img->stride[VPX_PLANE_Y] = -img->stride[VPX_PLANE_Y];
259 img->planes[VPX_PLANE_U] += (signed)((img->d_h >> img->y_chroma_shift) - 1)
260 * img->stride[VPX_PLANE_U];
261 img->stride[VPX_PLANE_U] = -img->stride[VPX_PLANE_U];
263 img->planes[VPX_PLANE_V] += (signed)((img->d_h >> img->y_chroma_shift) - 1)
264 * img->stride[VPX_PLANE_V];
265 img->stride[VPX_PLANE_V] = -img->stride[VPX_PLANE_V];
267 img->planes[VPX_PLANE_ALPHA] += (signed)(img->d_h - 1) * img->stride[VPX_PLANE_ALPHA];
268 img->stride[VPX_PLANE_ALPHA] = -img->stride[VPX_PLANE_ALPHA];
269 }
271 void vpx_img_free(vpx_image_t *img) {
272 if (img) {
273 if (img->img_data && img->img_data_owner)
274 img_buf_free(img->img_data);
276 if (img->self_allocd)
277 free(img);
278 }
279 }
