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 "./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. 24 static 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. 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 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 } 146 147 VP8StatusCode 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 } 171 172 VP8StatusCode 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 218 219 int 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 } 227 228 void 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 } 236 237 void 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!) 249 void 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 } 258 259 VP8StatusCode 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 } 291 292 int 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
