1 // Copyright 2011 Google Inc. All Rights Reserved.
2 //
3 // Use of this source code is governed by a BSD-style license
4 // that can be found in the COPYING file in the root of the source
5 // tree. An additional intellectual property rights grant can be found
6 // in the file PATENTS. All contributing project authors may
7 // be found in the AUTHORS file in the root of the source tree.
8 // -----------------------------------------------------------------------------
9 //
10 // Everything about WebPDecBuffer
11 //
12 // Author: Skal (pascal.massimino@gmail.com)
13
14 #include <stdlib.h>
15
16 #include "src/dec/vp8i_dec.h"
17 #include "src/dec/webpi_dec.h"
18 #include "src/utils/utils.h"
19
20 //------------------------------------------------------------------------------
21 // WebPDecBuffer
22
23 // Number of bytes per pixel for the different color-spaces.
24 static const uint8_t kModeBpp[MODE_LAST] = {
25 3, 4, 3, 4, 4, 2, 2,
26 4, 4, 4, 2, // pre-multiplied modes
27 1, 1 };
28
29 // Check that webp_csp_mode is within the bounds of WEBP_CSP_MODE.
30 // Convert to an integer to handle both the unsigned/signed enum cases
31 // without the need for casting to remove type limit warnings.
IsValidColorspace(int webp_csp_mode)32 static int IsValidColorspace(int webp_csp_mode) {
33 return (webp_csp_mode >= MODE_RGB && webp_csp_mode < MODE_LAST);
34 }
35
36 // strictly speaking, the very last (or first, if flipped) row
37 // doesn't require padding.
38 #define MIN_BUFFER_SIZE(WIDTH, HEIGHT, STRIDE) \
39 ((uint64_t)(STRIDE) * ((HEIGHT) - 1) + (WIDTH))
40
CheckDecBuffer(const WebPDecBuffer * const buffer)41 static VP8StatusCode CheckDecBuffer(const WebPDecBuffer* const buffer) {
42 int ok = 1;
43 const WEBP_CSP_MODE mode = buffer->colorspace;
44 const int width = buffer->width;
45 const int height = buffer->height;
46 if (!IsValidColorspace(mode)) {
47 ok = 0;
48 } else if (!WebPIsRGBMode(mode)) { // YUV checks
49 const WebPYUVABuffer* const buf = &buffer->u.YUVA;
50 const int uv_width = (width + 1) / 2;
51 const int uv_height = (height + 1) / 2;
52 const int y_stride = abs(buf->y_stride);
53 const int u_stride = abs(buf->u_stride);
54 const int v_stride = abs(buf->v_stride);
55 const int a_stride = abs(buf->a_stride);
56 const uint64_t y_size = MIN_BUFFER_SIZE(width, height, y_stride);
57 const uint64_t u_size = MIN_BUFFER_SIZE(uv_width, uv_height, u_stride);
58 const uint64_t v_size = MIN_BUFFER_SIZE(uv_width, uv_height, v_stride);
59 const uint64_t a_size = MIN_BUFFER_SIZE(width, height, a_stride);
60 ok &= (y_size <= buf->y_size);
61 ok &= (u_size <= buf->u_size);
62 ok &= (v_size <= buf->v_size);
63 ok &= (y_stride >= width);
64 ok &= (u_stride >= uv_width);
65 ok &= (v_stride >= uv_width);
66 ok &= (buf->y != NULL);
67 ok &= (buf->u != NULL);
68 ok &= (buf->v != NULL);
69 if (mode == MODE_YUVA) {
70 ok &= (a_stride >= width);
71 ok &= (a_size <= buf->a_size);
72 ok &= (buf->a != NULL);
73 }
74 } else { // RGB checks
75 const WebPRGBABuffer* const buf = &buffer->u.RGBA;
76 const int stride = abs(buf->stride);
77 const uint64_t size =
78 MIN_BUFFER_SIZE(width * kModeBpp[mode], height, stride);
79 ok &= (size <= buf->size);
80 ok &= (stride >= width * kModeBpp[mode]);
81 ok &= (buf->rgba != NULL);
82 }
83 return ok ? VP8_STATUS_OK : VP8_STATUS_INVALID_PARAM;
84 }
85 #undef MIN_BUFFER_SIZE
86
AllocateBuffer(WebPDecBuffer * const buffer)87 static VP8StatusCode AllocateBuffer(WebPDecBuffer* const buffer) {
88 const int w = buffer->width;
89 const int h = buffer->height;
90 const WEBP_CSP_MODE mode = buffer->colorspace;
91
92 if (w <= 0 || h <= 0 || !IsValidColorspace(mode)) {
93 return VP8_STATUS_INVALID_PARAM;
94 }
95
96 if (buffer->is_external_memory <= 0 && buffer->private_memory == NULL) {
97 uint8_t* output;
98 int uv_stride = 0, a_stride = 0;
99 uint64_t uv_size = 0, a_size = 0, total_size;
100 // We need memory and it hasn't been allocated yet.
101 // => initialize output buffer, now that dimensions are known.
102 int stride;
103 uint64_t size;
104
105 if ((uint64_t)w * kModeBpp[mode] >= (1ull << 32)) {
106 return VP8_STATUS_INVALID_PARAM;
107 }
108 stride = w * kModeBpp[mode];
109 size = (uint64_t)stride * h;
110 if (!WebPIsRGBMode(mode)) {
111 uv_stride = (w + 1) / 2;
112 uv_size = (uint64_t)uv_stride * ((h + 1) / 2);
113 if (mode == MODE_YUVA) {
114 a_stride = w;
115 a_size = (uint64_t)a_stride * h;
116 }
117 }
118 total_size = size + 2 * uv_size + a_size;
119
120 // Security/sanity checks
121 output = (uint8_t*)WebPSafeMalloc(total_size, sizeof(*output));
122 if (output == NULL) {
123 return VP8_STATUS_OUT_OF_MEMORY;
124 }
125 buffer->private_memory = output;
126
127 if (!WebPIsRGBMode(mode)) { // YUVA initialization
128 WebPYUVABuffer* const buf = &buffer->u.YUVA;
129 buf->y = output;
130 buf->y_stride = stride;
131 buf->y_size = (size_t)size;
132 buf->u = output + size;
133 buf->u_stride = uv_stride;
134 buf->u_size = (size_t)uv_size;
135 buf->v = output + size + uv_size;
136 buf->v_stride = uv_stride;
137 buf->v_size = (size_t)uv_size;
138 if (mode == MODE_YUVA) {
139 buf->a = output + size + 2 * uv_size;
140 }
141 buf->a_size = (size_t)a_size;
142 buf->a_stride = a_stride;
143 } else { // RGBA initialization
144 WebPRGBABuffer* const buf = &buffer->u.RGBA;
145 buf->rgba = output;
146 buf->stride = stride;
147 buf->size = (size_t)size;
148 }
149 }
150 return CheckDecBuffer(buffer);
151 }
152
WebPFlipBuffer(WebPDecBuffer * const buffer)153 VP8StatusCode WebPFlipBuffer(WebPDecBuffer* const buffer) {
154 if (buffer == NULL) {
155 return VP8_STATUS_INVALID_PARAM;
156 }
157 if (WebPIsRGBMode(buffer->colorspace)) {
158 WebPRGBABuffer* const buf = &buffer->u.RGBA;
159 buf->rgba += (buffer->height - 1) * buf->stride;
160 buf->stride = -buf->stride;
161 } else {
162 WebPYUVABuffer* const buf = &buffer->u.YUVA;
163 const int H = buffer->height;
164 buf->y += (H - 1) * buf->y_stride;
165 buf->y_stride = -buf->y_stride;
166 buf->u += ((H - 1) >> 1) * buf->u_stride;
167 buf->u_stride = -buf->u_stride;
168 buf->v += ((H - 1) >> 1) * buf->v_stride;
169 buf->v_stride = -buf->v_stride;
170 if (buf->a != NULL) {
171 buf->a += (H - 1) * buf->a_stride;
172 buf->a_stride = -buf->a_stride;
173 }
174 }
175 return VP8_STATUS_OK;
176 }
177
WebPAllocateDecBuffer(int width,int height,const WebPDecoderOptions * const options,WebPDecBuffer * const buffer)178 VP8StatusCode WebPAllocateDecBuffer(int width, int height,
179 const WebPDecoderOptions* const options,
180 WebPDecBuffer* const buffer) {
181 VP8StatusCode status;
182 if (buffer == NULL || width <= 0 || height <= 0) {
183 return VP8_STATUS_INVALID_PARAM;
184 }
185 if (options != NULL) { // First, apply options if there is any.
186 if (options->use_cropping) {
187 const int cw = options->crop_width;
188 const int ch = options->crop_height;
189 const int x = options->crop_left & ~1;
190 const int y = options->crop_top & ~1;
191 if (x < 0 || y < 0 || cw <= 0 || ch <= 0 ||
192 x + cw > width || y + ch > height) {
193 return VP8_STATUS_INVALID_PARAM; // out of frame boundary.
194 }
195 width = cw;
196 height = ch;
197 }
198
199 if (options->use_scaling) {
200 #if !defined(WEBP_REDUCE_SIZE)
201 int scaled_width = options->scaled_width;
202 int scaled_height = options->scaled_height;
203 if (!WebPRescalerGetScaledDimensions(
204 width, height, &scaled_width, &scaled_height)) {
205 return VP8_STATUS_INVALID_PARAM;
206 }
207 width = scaled_width;
208 height = scaled_height;
209 #else
210 return VP8_STATUS_INVALID_PARAM; // rescaling not supported
211 #endif
212 }
213 }
214 buffer->width = width;
215 buffer->height = height;
216
217 // Then, allocate buffer for real.
218 status = AllocateBuffer(buffer);
219 if (status != VP8_STATUS_OK) return status;
220
221 // Use the stride trick if vertical flip is needed.
222 if (options != NULL && options->flip) {
223 status = WebPFlipBuffer(buffer);
224 }
225 return status;
226 }
227
228 //------------------------------------------------------------------------------
229 // constructors / destructors
230
WebPInitDecBufferInternal(WebPDecBuffer * buffer,int version)231 int WebPInitDecBufferInternal(WebPDecBuffer* buffer, int version) {
232 if (WEBP_ABI_IS_INCOMPATIBLE(version, WEBP_DECODER_ABI_VERSION)) {
233 return 0; // version mismatch
234 }
235 if (buffer == NULL) return 0;
236 memset(buffer, 0, sizeof(*buffer));
237 return 1;
238 }
239
WebPFreeDecBuffer(WebPDecBuffer * buffer)240 void WebPFreeDecBuffer(WebPDecBuffer* buffer) {
241 if (buffer != NULL) {
242 if (buffer->is_external_memory <= 0) {
243 WebPSafeFree(buffer->private_memory);
244 }
245 buffer->private_memory = NULL;
246 }
247 }
248
WebPCopyDecBuffer(const WebPDecBuffer * const src,WebPDecBuffer * const dst)249 void WebPCopyDecBuffer(const WebPDecBuffer* const src,
250 WebPDecBuffer* const dst) {
251 if (src != NULL && dst != NULL) {
252 *dst = *src;
253 if (src->private_memory != NULL) {
254 dst->is_external_memory = 1; // dst buffer doesn't own the memory.
255 dst->private_memory = NULL;
256 }
257 }
258 }
259
260 // Copy and transfer ownership from src to dst (beware of parameter order!)
WebPGrabDecBuffer(WebPDecBuffer * const src,WebPDecBuffer * const dst)261 void WebPGrabDecBuffer(WebPDecBuffer* const src, WebPDecBuffer* const dst) {
262 if (src != NULL && dst != NULL) {
263 *dst = *src;
264 if (src->private_memory != NULL) {
265 src->is_external_memory = 1; // src relinquishes ownership
266 src->private_memory = NULL;
267 }
268 }
269 }
270
WebPCopyDecBufferPixels(const WebPDecBuffer * const src_buf,WebPDecBuffer * const dst_buf)271 VP8StatusCode WebPCopyDecBufferPixels(const WebPDecBuffer* const src_buf,
272 WebPDecBuffer* const dst_buf) {
273 assert(src_buf != NULL && dst_buf != NULL);
274 assert(src_buf->colorspace == dst_buf->colorspace);
275
276 dst_buf->width = src_buf->width;
277 dst_buf->height = src_buf->height;
278 if (CheckDecBuffer(dst_buf) != VP8_STATUS_OK) {
279 return VP8_STATUS_INVALID_PARAM;
280 }
281 if (WebPIsRGBMode(src_buf->colorspace)) {
282 const WebPRGBABuffer* const src = &src_buf->u.RGBA;
283 const WebPRGBABuffer* const dst = &dst_buf->u.RGBA;
284 WebPCopyPlane(src->rgba, src->stride, dst->rgba, dst->stride,
285 src_buf->width * kModeBpp[src_buf->colorspace],
286 src_buf->height);
287 } else {
288 const WebPYUVABuffer* const src = &src_buf->u.YUVA;
289 const WebPYUVABuffer* const dst = &dst_buf->u.YUVA;
290 WebPCopyPlane(src->y, src->y_stride, dst->y, dst->y_stride,
291 src_buf->width, src_buf->height);
292 WebPCopyPlane(src->u, src->u_stride, dst->u, dst->u_stride,
293 (src_buf->width + 1) / 2, (src_buf->height + 1) / 2);
294 WebPCopyPlane(src->v, src->v_stride, dst->v, dst->v_stride,
295 (src_buf->width + 1) / 2, (src_buf->height + 1) / 2);
296 if (WebPIsAlphaMode(src_buf->colorspace)) {
297 WebPCopyPlane(src->a, src->a_stride, dst->a, dst->a_stride,
298 src_buf->width, src_buf->height);
299 }
300 }
301 return VP8_STATUS_OK;
302 }
303
WebPAvoidSlowMemory(const WebPDecBuffer * const output,const WebPBitstreamFeatures * const features)304 int WebPAvoidSlowMemory(const WebPDecBuffer* const output,
305 const WebPBitstreamFeatures* const features) {
306 assert(output != NULL);
307 return (output->is_external_memory >= 2) &&
308 WebPIsPremultipliedMode(output->colorspace) &&
309 (features != NULL && features->has_alpha);
310 }
311
312 //------------------------------------------------------------------------------
313