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 (at) 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. 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 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 = 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 86 static 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 int stride; 102 uint64_t size; 103 104 if ((uint64_t)w * kModeBpp[mode] >= (1ull << 32)) { 105 return VP8_STATUS_INVALID_PARAM; 106 } 107 stride = w * kModeBpp[mode]; 108 size = (uint64_t)stride * h; 109 if (!WebPIsRGBMode(mode)) { 110 uv_stride = (w + 1) / 2; 111 uv_size = (uint64_t)uv_stride * ((h + 1) / 2); 112 if (mode == MODE_YUVA) { 113 a_stride = w; 114 a_size = (uint64_t)a_stride * h; 115 } 116 } 117 total_size = size + 2 * uv_size + a_size; 118 119 // Security/sanity checks 120 output = (uint8_t*)WebPSafeMalloc(total_size, sizeof(*output)); 121 if (output == NULL) { 122 return VP8_STATUS_OUT_OF_MEMORY; 123 } 124 buffer->private_memory = output; 125 126 if (!WebPIsRGBMode(mode)) { // YUVA initialization 127 WebPYUVABuffer* const buf = &buffer->u.YUVA; 128 buf->y = output; 129 buf->y_stride = stride; 130 buf->y_size = (size_t)size; 131 buf->u = output + size; 132 buf->u_stride = uv_stride; 133 buf->u_size = (size_t)uv_size; 134 buf->v = output + size + uv_size; 135 buf->v_stride = uv_stride; 136 buf->v_size = (size_t)uv_size; 137 if (mode == MODE_YUVA) { 138 buf->a = output + size + 2 * uv_size; 139 } 140 buf->a_size = (size_t)a_size; 141 buf->a_stride = a_stride; 142 } else { // RGBA initialization 143 WebPRGBABuffer* const buf = &buffer->u.RGBA; 144 buf->rgba = output; 145 buf->stride = stride; 146 buf->size = (size_t)size; 147 } 148 } 149 return CheckDecBuffer(buffer); 150 } 151 152 VP8StatusCode WebPFlipBuffer(WebPDecBuffer* const buffer) { 153 if (buffer == NULL) { 154 return VP8_STATUS_INVALID_PARAM; 155 } 156 if (WebPIsRGBMode(buffer->colorspace)) { 157 WebPRGBABuffer* const buf = &buffer->u.RGBA; 158 buf->rgba += (buffer->height - 1) * buf->stride; 159 buf->stride = -buf->stride; 160 } else { 161 WebPYUVABuffer* const buf = &buffer->u.YUVA; 162 const int H = buffer->height; 163 buf->y += (H - 1) * buf->y_stride; 164 buf->y_stride = -buf->y_stride; 165 buf->u += ((H - 1) >> 1) * buf->u_stride; 166 buf->u_stride = -buf->u_stride; 167 buf->v += ((H - 1) >> 1) * buf->v_stride; 168 buf->v_stride = -buf->v_stride; 169 if (buf->a != NULL) { 170 buf->a += (H - 1) * buf->a_stride; 171 buf->a_stride = -buf->a_stride; 172 } 173 } 174 return VP8_STATUS_OK; 175 } 176 177 VP8StatusCode WebPAllocateDecBuffer(int width, int height, 178 const WebPDecoderOptions* const options, 179 WebPDecBuffer* const buffer) { 180 VP8StatusCode status; 181 if (buffer == NULL || width <= 0 || height <= 0) { 182 return VP8_STATUS_INVALID_PARAM; 183 } 184 if (options != NULL) { // First, apply options if there is any. 185 if (options->use_cropping) { 186 const int cw = options->crop_width; 187 const int ch = options->crop_height; 188 const int x = options->crop_left & ~1; 189 const int y = options->crop_top & ~1; 190 if (x < 0 || y < 0 || cw <= 0 || ch <= 0 || 191 x + cw > width || y + ch > height) { 192 return VP8_STATUS_INVALID_PARAM; // out of frame boundary. 193 } 194 width = cw; 195 height = ch; 196 } 197 198 if (options->use_scaling) { 199 #if !defined(WEBP_REDUCE_SIZE) 200 int scaled_width = options->scaled_width; 201 int scaled_height = options->scaled_height; 202 if (!WebPRescalerGetScaledDimensions( 203 width, height, &scaled_width, &scaled_height)) { 204 return VP8_STATUS_INVALID_PARAM; 205 } 206 width = scaled_width; 207 height = scaled_height; 208 #else 209 return VP8_STATUS_INVALID_PARAM; // rescaling not supported 210 #endif 211 } 212 } 213 buffer->width = width; 214 buffer->height = height; 215 216 // Then, allocate buffer for real. 217 status = AllocateBuffer(buffer); 218 if (status != VP8_STATUS_OK) return status; 219 220 // Use the stride trick if vertical flip is needed. 221 if (options != NULL && options->flip) { 222 status = WebPFlipBuffer(buffer); 223 } 224 return status; 225 } 226 227 //------------------------------------------------------------------------------ 228 // constructors / destructors 229 230 int WebPInitDecBufferInternal(WebPDecBuffer* buffer, int version) { 231 if (WEBP_ABI_IS_INCOMPATIBLE(version, WEBP_DECODER_ABI_VERSION)) { 232 return 0; // version mismatch 233 } 234 if (buffer == NULL) return 0; 235 memset(buffer, 0, sizeof(*buffer)); 236 return 1; 237 } 238 239 void WebPFreeDecBuffer(WebPDecBuffer* buffer) { 240 if (buffer != NULL) { 241 if (buffer->is_external_memory <= 0) { 242 WebPSafeFree(buffer->private_memory); 243 } 244 buffer->private_memory = NULL; 245 } 246 } 247 248 void WebPCopyDecBuffer(const WebPDecBuffer* const src, 249 WebPDecBuffer* const dst) { 250 if (src != NULL && dst != NULL) { 251 *dst = *src; 252 if (src->private_memory != NULL) { 253 dst->is_external_memory = 1; // dst buffer doesn't own the memory. 254 dst->private_memory = NULL; 255 } 256 } 257 } 258 259 // Copy and transfer ownership from src to dst (beware of parameter order!) 260 void WebPGrabDecBuffer(WebPDecBuffer* const src, WebPDecBuffer* const dst) { 261 if (src != NULL && dst != NULL) { 262 *dst = *src; 263 if (src->private_memory != NULL) { 264 src->is_external_memory = 1; // src relinquishes ownership 265 src->private_memory = NULL; 266 } 267 } 268 } 269 270 VP8StatusCode WebPCopyDecBufferPixels(const WebPDecBuffer* const src_buf, 271 WebPDecBuffer* const dst_buf) { 272 assert(src_buf != NULL && dst_buf != NULL); 273 assert(src_buf->colorspace == dst_buf->colorspace); 274 275 dst_buf->width = src_buf->width; 276 dst_buf->height = src_buf->height; 277 if (CheckDecBuffer(dst_buf) != VP8_STATUS_OK) { 278 return VP8_STATUS_INVALID_PARAM; 279 } 280 if (WebPIsRGBMode(src_buf->colorspace)) { 281 const WebPRGBABuffer* const src = &src_buf->u.RGBA; 282 const WebPRGBABuffer* const dst = &dst_buf->u.RGBA; 283 WebPCopyPlane(src->rgba, src->stride, dst->rgba, dst->stride, 284 src_buf->width * kModeBpp[src_buf->colorspace], 285 src_buf->height); 286 } else { 287 const WebPYUVABuffer* const src = &src_buf->u.YUVA; 288 const WebPYUVABuffer* const dst = &dst_buf->u.YUVA; 289 WebPCopyPlane(src->y, src->y_stride, dst->y, dst->y_stride, 290 src_buf->width, src_buf->height); 291 WebPCopyPlane(src->u, src->u_stride, dst->u, dst->u_stride, 292 (src_buf->width + 1) / 2, (src_buf->height + 1) / 2); 293 WebPCopyPlane(src->v, src->v_stride, dst->v, dst->v_stride, 294 (src_buf->width + 1) / 2, (src_buf->height + 1) / 2); 295 if (WebPIsAlphaMode(src_buf->colorspace)) { 296 WebPCopyPlane(src->a, src->a_stride, dst->a, dst->a_stride, 297 src_buf->width, src_buf->height); 298 } 299 } 300 return VP8_STATUS_OK; 301 } 302 303 int WebPAvoidSlowMemory(const WebPDecBuffer* const output, 304 const WebPBitstreamFeatures* const features) { 305 assert(output != NULL); 306 return (output->is_external_memory >= 2) && 307 WebPIsPremultipliedMode(output->colorspace) && 308 (features != NULL && features->has_alpha); 309 } 310 311 //------------------------------------------------------------------------------ 312
