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 "./vp8i_dec.h"
17#include "./webpi_dec.h"
18#include "../utils/utils.h"
19
20//------------------------------------------------------------------------------
21// WebPDecBuffer
22
23// Number of bytes per pixel for the different color-spaces.
24static const int 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.
32static 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
41static 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 = MIN_BUFFER_SIZE(width, height, stride);
78 ok &= (size <= buf->size);
79 ok &= (stride >= width * kModeBpp[mode]);
80 ok &= (buf->rgba != NULL);
81 }
82 return ok ? VP8_STATUS_OK : VP8_STATUS_INVALID_PARAM;
83}
84#undef MIN_BUFFER_SIZE
85
86static VP8StatusCode AllocateBuffer(WebPDecBuffer* const buffer) {
87 const int w = buffer->width;
88 const int h = buffer->height;
89 const WEBP_CSP_MODE mode = buffer->colorspace;
90
91 if (w <= 0 || h <= 0 || !IsValidColorspace(mode)) {
92 return VP8_STATUS_INVALID_PARAM;
93 }
94
95 if (buffer->is_external_memory <= 0 && buffer->private_memory == NULL) {
96 uint8_t* output;
97 int uv_stride = 0, a_stride = 0;
98 uint64_t uv_size = 0, a_size = 0, total_size;
99 // We need memory and it hasn't been allocated yet.
100 // => initialize output buffer, now that dimensions are known.
101 const int stride = w * kModeBpp[mode];
102 const uint64_t size = (uint64_t)stride * h;
103
104 if (!WebPIsRGBMode(mode)) {
105 uv_stride = (w + 1) / 2;
106 uv_size = (uint64_t)uv_stride * ((h + 1) / 2);
107 if (mode == MODE_YUVA) {
108 a_stride = w;
109 a_size = (uint64_t)a_stride * h;
110 }
111 }
112 total_size = size + 2 * uv_size + a_size;
113
114 // Security/sanity checks
115 output = (uint8_t*)WebPSafeMalloc(total_size, sizeof(*output));
116 if (output == NULL) {
117 return VP8_STATUS_OUT_OF_MEMORY;
118 }
119 buffer->private_memory = output;
120
121 if (!WebPIsRGBMode(mode)) { // YUVA initialization
122 WebPYUVABuffer* const buf = &buffer->u.YUVA;
123 buf->y = output;
124 buf->y_stride = stride;
125 buf->y_size = (size_t)size;
126 buf->u = output + size;
127 buf->u_stride = uv_stride;
128 buf->u_size = (size_t)uv_size;
129 buf->v = output + size + uv_size;
130 buf->v_stride = uv_stride;
131 buf->v_size = (size_t)uv_size;
132 if (mode == MODE_YUVA) {
133 buf->a = output + size + 2 * uv_size;
134 }
135 buf->a_size = (size_t)a_size;
136 buf->a_stride = a_stride;
137 } else { // RGBA initialization
138 WebPRGBABuffer* const buf = &buffer->u.RGBA;
139 buf->rgba = output;
140 buf->stride = stride;
141 buf->size = (size_t)size;
142 }
143 }
144 return CheckDecBuffer(buffer);
145}
146
147VP8StatusCode WebPFlipBuffer(WebPDecBuffer* const buffer) {
148 if (buffer == NULL) {
149 return VP8_STATUS_INVALID_PARAM;
150 }
151 if (WebPIsRGBMode(buffer->colorspace)) {
152 WebPRGBABuffer* const buf = &buffer->u.RGBA;
153 buf->rgba += (buffer->height - 1) * buf->stride;
154 buf->stride = -buf->stride;
155 } else {
156 WebPYUVABuffer* const buf = &buffer->u.YUVA;
157 const int H = buffer->height;
158 buf->y += (H - 1) * buf->y_stride;
159 buf->y_stride = -buf->y_stride;
160 buf->u += ((H - 1) >> 1) * buf->u_stride;
161 buf->u_stride = -buf->u_stride;
162 buf->v += ((H - 1) >> 1) * buf->v_stride;
163 buf->v_stride = -buf->v_stride;
164 if (buf->a != NULL) {
165 buf->a += (H - 1) * buf->a_stride;
166 buf->a_stride = -buf->a_stride;
167 }
168 }
169 return VP8_STATUS_OK;
170}
171
172VP8StatusCode WebPAllocateDecBuffer(int w, int h,
173 const WebPDecoderOptions* const options,
174 WebPDecBuffer* const out) {
175 VP8StatusCode status;
176 if (out == NULL || w <= 0 || h <= 0) {
177 return VP8_STATUS_INVALID_PARAM;
178 }
179 if (options != NULL) { // First, apply options if there is any.
180 if (options->use_cropping) {
181 const int cw = options->crop_width;
182 const int ch = options->crop_height;
183 const int x = options->crop_left & ~1;
184 const int y = options->crop_top & ~1;
185 if (x < 0 || y < 0 || cw <= 0 || ch <= 0 || x + cw > w || y + ch > h) {
186 return VP8_STATUS_INVALID_PARAM; // out of frame boundary.
187 }
188 w = cw;
189 h = ch;
190 }
191 if (options->use_scaling) {
192 int scaled_width = options->scaled_width;
193 int scaled_height = options->scaled_height;
194 if (!WebPRescalerGetScaledDimensions(
195 w, h, &scaled_width, &scaled_height)) {
196 return VP8_STATUS_INVALID_PARAM;
197 }
198 w = scaled_width;
199 h = scaled_height;
200 }
201 }
202 out->width = w;
203 out->height = h;
204
205 // Then, allocate buffer for real.
206 status = AllocateBuffer(out);
207 if (status != VP8_STATUS_OK) return status;
208
209 // Use the stride trick if vertical flip is needed.
210 if (options != NULL && options->flip) {
211 status = WebPFlipBuffer(out);
212 }
213 return status;
214}
215
216//------------------------------------------------------------------------------
217// constructors / destructors
218
219int WebPInitDecBufferInternal(WebPDecBuffer* buffer, int version) {
220 if (WEBP_ABI_IS_INCOMPATIBLE(version, WEBP_DECODER_ABI_VERSION)) {
221 return 0; // version mismatch
222 }
223 if (buffer == NULL) return 0;
224 memset(buffer, 0, sizeof(*buffer));
225 return 1;
226}
227
228void WebPFreeDecBuffer(WebPDecBuffer* buffer) {
229 if (buffer != NULL) {
230 if (buffer->is_external_memory <= 0) {
231 WebPSafeFree(buffer->private_memory);
232 }
233 buffer->private_memory = NULL;
234 }
235}
236
237void WebPCopyDecBuffer(const WebPDecBuffer* const src,
238 WebPDecBuffer* const dst) {
239 if (src != NULL && dst != NULL) {
240 *dst = *src;
241 if (src->private_memory != NULL) {
242 dst->is_external_memory = 1; // dst buffer doesn't own the memory.
243 dst->private_memory = NULL;
244 }
245 }
246}
247
248// Copy and transfer ownership from src to dst (beware of parameter order!)
249void WebPGrabDecBuffer(WebPDecBuffer* const src, WebPDecBuffer* const dst) {
250 if (src != NULL && dst != NULL) {
251 *dst = *src;
252 if (src->private_memory != NULL) {
253 src->is_external_memory = 1; // src relinquishes ownership
254 src->private_memory = NULL;
255 }
256 }
257}
258
259VP8StatusCode WebPCopyDecBufferPixels(const WebPDecBuffer* const src_buf,
260 WebPDecBuffer* const dst_buf) {
261 assert(src_buf != NULL && dst_buf != NULL);
262 assert(src_buf->colorspace == dst_buf->colorspace);
263
264 dst_buf->width = src_buf->width;
265 dst_buf->height = src_buf->height;
266 if (CheckDecBuffer(dst_buf) != VP8_STATUS_OK) {
267 return VP8_STATUS_INVALID_PARAM;
268 }
269 if (WebPIsRGBMode(src_buf->colorspace)) {
270 const WebPRGBABuffer* const src = &src_buf->u.RGBA;
271 const WebPRGBABuffer* const dst = &dst_buf->u.RGBA;
272 WebPCopyPlane(src->rgba, src->stride, dst->rgba, dst->stride,
273 src_buf->width * kModeBpp[src_buf->colorspace],
274 src_buf->height);
275 } else {
276 const WebPYUVABuffer* const src = &src_buf->u.YUVA;
277 const WebPYUVABuffer* const dst = &dst_buf->u.YUVA;
278 WebPCopyPlane(src->y, src->y_stride, dst->y, dst->y_stride,
279 src_buf->width, src_buf->height);
280 WebPCopyPlane(src->u, src->u_stride, dst->u, dst->u_stride,
281 (src_buf->width + 1) / 2, (src_buf->height + 1) / 2);
282 WebPCopyPlane(src->v, src->v_stride, dst->v, dst->v_stride,
283 (src_buf->width + 1) / 2, (src_buf->height + 1) / 2);
284 if (WebPIsAlphaMode(src_buf->colorspace)) {
285 WebPCopyPlane(src->a, src->a_stride, dst->a, dst->a_stride,
286 src_buf->width, src_buf->height);
287 }
288 }
289 return VP8_STATUS_OK;
290}
291
292int WebPAvoidSlowMemory(const WebPDecBuffer* const output,
293 const WebPBitstreamFeatures* const features) {
294 assert(output != NULL);
295 return (output->is_external_memory >= 2) &&
296 WebPIsPremultipliedMode(output->colorspace) &&
297 (features != NULL && features->has_alpha);
298}
299
300//------------------------------------------------------------------------------
301