Vikas Arora | a241572 | 2012-08-09 16:18:58 -0700 | [diff] [blame] | 1 | // Copyright 2010 Google Inc. All Rights Reserved. |
Eric Hassold | 9aea642 | 2011-01-04 17:22:46 -0800 | [diff] [blame] | 2 | // |
| 3 | // This code is licensed under the same terms as WebM: |
| 4 | // Software License Agreement: http://www.webmproject.org/license/software/ |
| 5 | // Additional IP Rights Grant: http://www.webmproject.org/license/additional/ |
| 6 | // ----------------------------------------------------------------------------- |
| 7 | // |
| 8 | // Main decoding functions for WEBP images. |
| 9 | // |
| 10 | // Author: Skal (pascal.massimino@gmail.com) |
| 11 | |
| 12 | #include <stdlib.h> |
Vikas Arora | a241572 | 2012-08-09 16:18:58 -0700 | [diff] [blame] | 13 | |
| 14 | #include "./vp8i.h" |
| 15 | #include "./vp8li.h" |
| 16 | #include "./webpi.h" |
| 17 | #include "webp/format_constants.h" |
Eric Hassold | 9aea642 | 2011-01-04 17:22:46 -0800 | [diff] [blame] | 18 | |
| 19 | #if defined(__cplusplus) || defined(c_plusplus) |
| 20 | extern "C" { |
| 21 | #endif |
| 22 | |
Vikas Arora | a241572 | 2012-08-09 16:18:58 -0700 | [diff] [blame] | 23 | //------------------------------------------------------------------------------ |
Eric Hassold | 9aea642 | 2011-01-04 17:22:46 -0800 | [diff] [blame] | 24 | // RIFF layout is: |
Vikas Arora | a241572 | 2012-08-09 16:18:58 -0700 | [diff] [blame] | 25 | // Offset tag |
Eric Hassold | 9aea642 | 2011-01-04 17:22:46 -0800 | [diff] [blame] | 26 | // 0...3 "RIFF" 4-byte tag |
| 27 | // 4...7 size of image data (including metadata) starting at offset 8 |
| 28 | // 8...11 "WEBP" our form-type signature |
Vikas Arora | a241572 | 2012-08-09 16:18:58 -0700 | [diff] [blame] | 29 | // The RIFF container (12 bytes) is followed by appropriate chunks: |
| 30 | // 12..15 "VP8 ": 4-bytes tags, signaling the use of VP8 video format |
Eric Hassold | 9aea642 | 2011-01-04 17:22:46 -0800 | [diff] [blame] | 31 | // 16..19 size of the raw VP8 image data, starting at offset 20 |
| 32 | // 20.... the VP8 bytes |
Vikas Arora | a241572 | 2012-08-09 16:18:58 -0700 | [diff] [blame] | 33 | // Or, |
| 34 | // 12..15 "VP8L": 4-bytes tags, signaling the use of VP8L lossless format |
| 35 | // 16..19 size of the raw VP8L image data, starting at offset 20 |
| 36 | // 20.... the VP8L bytes |
| 37 | // Or, |
| 38 | // 12..15 "VP8X": 4-bytes tags, describing the extended-VP8 chunk. |
| 39 | // 16..19 size of the VP8X chunk starting at offset 20. |
| 40 | // 20..23 VP8X flags bit-map corresponding to the chunk-types present. |
| 41 | // 24..26 Width of the Canvas Image. |
| 42 | // 27..29 Height of the Canvas Image. |
Vikas Arora | 1e7bf88 | 2013-03-13 16:43:18 -0700 | [diff] [blame^] | 43 | // There can be extra chunks after the "VP8X" chunk (ICCP, FRGM, ANMF, VP8, |
| 44 | // VP8L, XMP, EXIF ...) |
Vikas Arora | a241572 | 2012-08-09 16:18:58 -0700 | [diff] [blame] | 45 | // All sizes are in little-endian order. |
| 46 | // Note: chunk data size must be padded to multiple of 2 when written. |
Eric Hassold | 9aea642 | 2011-01-04 17:22:46 -0800 | [diff] [blame] | 47 | |
Vikas Arora | a241572 | 2012-08-09 16:18:58 -0700 | [diff] [blame] | 48 | static WEBP_INLINE uint32_t get_le24(const uint8_t* const data) { |
| 49 | return data[0] | (data[1] << 8) | (data[2] << 16); |
Eric Hassold | 9aea642 | 2011-01-04 17:22:46 -0800 | [diff] [blame] | 50 | } |
| 51 | |
Vikas Arora | a241572 | 2012-08-09 16:18:58 -0700 | [diff] [blame] | 52 | static WEBP_INLINE uint32_t get_le32(const uint8_t* const data) { |
| 53 | return (uint32_t)get_le24(data) | (data[3] << 24); |
| 54 | } |
| 55 | |
| 56 | // Validates the RIFF container (if detected) and skips over it. |
| 57 | // If a RIFF container is detected, |
| 58 | // Returns VP8_STATUS_BITSTREAM_ERROR for invalid header, and |
| 59 | // VP8_STATUS_OK otherwise. |
| 60 | // In case there are not enough bytes (partial RIFF container), return 0 for |
| 61 | // *riff_size. Else return the RIFF size extracted from the header. |
| 62 | static VP8StatusCode ParseRIFF(const uint8_t** const data, |
| 63 | size_t* const data_size, |
| 64 | size_t* const riff_size) { |
| 65 | assert(data != NULL); |
| 66 | assert(data_size != NULL); |
| 67 | assert(riff_size != NULL); |
| 68 | |
| 69 | *riff_size = 0; // Default: no RIFF present. |
| 70 | if (*data_size >= RIFF_HEADER_SIZE && !memcmp(*data, "RIFF", TAG_SIZE)) { |
| 71 | if (memcmp(*data + 8, "WEBP", TAG_SIZE)) { |
| 72 | return VP8_STATUS_BITSTREAM_ERROR; // Wrong image file signature. |
Eric Hassold | 9aea642 | 2011-01-04 17:22:46 -0800 | [diff] [blame] | 73 | } else { |
Vikas Arora | a241572 | 2012-08-09 16:18:58 -0700 | [diff] [blame] | 74 | const uint32_t size = get_le32(*data + TAG_SIZE); |
| 75 | // Check that we have at least one chunk (i.e "WEBP" + "VP8?nnnn"). |
| 76 | if (size < TAG_SIZE + CHUNK_HEADER_SIZE) { |
| 77 | return VP8_STATUS_BITSTREAM_ERROR; |
Eric Hassold | 9aea642 | 2011-01-04 17:22:46 -0800 | [diff] [blame] | 78 | } |
Geremy Condra | 276905d | 2012-11-01 19:10:00 -0700 | [diff] [blame] | 79 | if (size > MAX_CHUNK_PAYLOAD) { |
| 80 | return VP8_STATUS_BITSTREAM_ERROR; |
| 81 | } |
Vikas Arora | 03d5e34 | 2011-06-02 23:59:44 +0530 | [diff] [blame] | 82 | // We have a RIFF container. Skip it. |
Vikas Arora | a241572 | 2012-08-09 16:18:58 -0700 | [diff] [blame] | 83 | *riff_size = size; |
| 84 | *data += RIFF_HEADER_SIZE; |
| 85 | *data_size -= RIFF_HEADER_SIZE; |
Eric Hassold | 9aea642 | 2011-01-04 17:22:46 -0800 | [diff] [blame] | 86 | } |
Eric Hassold | 9aea642 | 2011-01-04 17:22:46 -0800 | [diff] [blame] | 87 | } |
Vikas Arora | a241572 | 2012-08-09 16:18:58 -0700 | [diff] [blame] | 88 | return VP8_STATUS_OK; |
Eric Hassold | 9aea642 | 2011-01-04 17:22:46 -0800 | [diff] [blame] | 89 | } |
| 90 | |
Vikas Arora | a241572 | 2012-08-09 16:18:58 -0700 | [diff] [blame] | 91 | // Validates the VP8X header and skips over it. |
| 92 | // Returns VP8_STATUS_BITSTREAM_ERROR for invalid VP8X header, |
| 93 | // VP8_STATUS_NOT_ENOUGH_DATA in case of insufficient data, and |
| 94 | // VP8_STATUS_OK otherwise. |
| 95 | // If a VP8X chunk is found, found_vp8x is set to true and *width_ptr, |
| 96 | // *height_ptr and *flags_ptr are set to the corresponding values extracted |
| 97 | // from the VP8X chunk. |
| 98 | static VP8StatusCode ParseVP8X(const uint8_t** const data, |
| 99 | size_t* const data_size, |
| 100 | int* const found_vp8x, |
| 101 | int* const width_ptr, int* const height_ptr, |
| 102 | uint32_t* const flags_ptr) { |
| 103 | const uint32_t vp8x_size = CHUNK_HEADER_SIZE + VP8X_CHUNK_SIZE; |
| 104 | assert(data != NULL); |
| 105 | assert(data_size != NULL); |
| 106 | assert(found_vp8x != NULL); |
| 107 | |
| 108 | *found_vp8x = 0; |
| 109 | |
| 110 | if (*data_size < CHUNK_HEADER_SIZE) { |
| 111 | return VP8_STATUS_NOT_ENOUGH_DATA; // Insufficient data. |
| 112 | } |
| 113 | |
| 114 | if (!memcmp(*data, "VP8X", TAG_SIZE)) { |
| 115 | int width, height; |
| 116 | uint32_t flags; |
| 117 | const uint32_t chunk_size = get_le32(*data + TAG_SIZE); |
| 118 | if (chunk_size != VP8X_CHUNK_SIZE) { |
| 119 | return VP8_STATUS_BITSTREAM_ERROR; // Wrong chunk size. |
| 120 | } |
| 121 | |
| 122 | // Verify if enough data is available to validate the VP8X chunk. |
| 123 | if (*data_size < vp8x_size) { |
| 124 | return VP8_STATUS_NOT_ENOUGH_DATA; // Insufficient data. |
| 125 | } |
| 126 | flags = get_le32(*data + 8); |
| 127 | width = 1 + get_le24(*data + 12); |
| 128 | height = 1 + get_le24(*data + 15); |
| 129 | if (width * (uint64_t)height >= MAX_IMAGE_AREA) { |
| 130 | return VP8_STATUS_BITSTREAM_ERROR; // image is too large |
| 131 | } |
| 132 | |
| 133 | if (flags_ptr != NULL) *flags_ptr = flags; |
| 134 | if (width_ptr != NULL) *width_ptr = width; |
| 135 | if (height_ptr != NULL) *height_ptr = height; |
| 136 | // Skip over VP8X header bytes. |
| 137 | *data += vp8x_size; |
| 138 | *data_size -= vp8x_size; |
| 139 | *found_vp8x = 1; |
| 140 | } |
| 141 | return VP8_STATUS_OK; |
| 142 | } |
| 143 | |
| 144 | // Skips to the next VP8/VP8L chunk header in the data given the size of the |
| 145 | // RIFF chunk 'riff_size'. |
| 146 | // Returns VP8_STATUS_BITSTREAM_ERROR if any invalid chunk size is encountered, |
| 147 | // VP8_STATUS_NOT_ENOUGH_DATA in case of insufficient data, and |
| 148 | // VP8_STATUS_OK otherwise. |
| 149 | // If an alpha chunk is found, *alpha_data and *alpha_size are set |
| 150 | // appropriately. |
| 151 | static VP8StatusCode ParseOptionalChunks(const uint8_t** const data, |
| 152 | size_t* const data_size, |
| 153 | size_t const riff_size, |
| 154 | const uint8_t** const alpha_data, |
| 155 | size_t* const alpha_size) { |
| 156 | const uint8_t* buf; |
| 157 | size_t buf_size; |
| 158 | uint32_t total_size = TAG_SIZE + // "WEBP". |
| 159 | CHUNK_HEADER_SIZE + // "VP8Xnnnn". |
| 160 | VP8X_CHUNK_SIZE; // data. |
| 161 | assert(data != NULL); |
| 162 | assert(data_size != NULL); |
| 163 | buf = *data; |
| 164 | buf_size = *data_size; |
| 165 | |
| 166 | assert(alpha_data != NULL); |
| 167 | assert(alpha_size != NULL); |
| 168 | *alpha_data = NULL; |
| 169 | *alpha_size = 0; |
| 170 | |
| 171 | while (1) { |
| 172 | uint32_t chunk_size; |
| 173 | uint32_t disk_chunk_size; // chunk_size with padding |
| 174 | |
| 175 | *data = buf; |
| 176 | *data_size = buf_size; |
| 177 | |
| 178 | if (buf_size < CHUNK_HEADER_SIZE) { // Insufficient data. |
| 179 | return VP8_STATUS_NOT_ENOUGH_DATA; |
| 180 | } |
| 181 | |
| 182 | chunk_size = get_le32(buf + TAG_SIZE); |
Geremy Condra | 276905d | 2012-11-01 19:10:00 -0700 | [diff] [blame] | 183 | if (chunk_size > MAX_CHUNK_PAYLOAD) { |
| 184 | return VP8_STATUS_BITSTREAM_ERROR; // Not a valid chunk size. |
| 185 | } |
Vikas Arora | a241572 | 2012-08-09 16:18:58 -0700 | [diff] [blame] | 186 | // For odd-sized chunk-payload, there's one byte padding at the end. |
| 187 | disk_chunk_size = (CHUNK_HEADER_SIZE + chunk_size + 1) & ~1; |
| 188 | total_size += disk_chunk_size; |
| 189 | |
| 190 | // Check that total bytes skipped so far does not exceed riff_size. |
| 191 | if (riff_size > 0 && (total_size > riff_size)) { |
| 192 | return VP8_STATUS_BITSTREAM_ERROR; // Not a valid chunk size. |
| 193 | } |
| 194 | |
| 195 | if (buf_size < disk_chunk_size) { // Insufficient data. |
| 196 | return VP8_STATUS_NOT_ENOUGH_DATA; |
| 197 | } |
| 198 | |
| 199 | if (!memcmp(buf, "ALPH", TAG_SIZE)) { // A valid ALPH header. |
| 200 | *alpha_data = buf + CHUNK_HEADER_SIZE; |
| 201 | *alpha_size = chunk_size; |
| 202 | } else if (!memcmp(buf, "VP8 ", TAG_SIZE) || |
| 203 | !memcmp(buf, "VP8L", TAG_SIZE)) { // A valid VP8/VP8L header. |
| 204 | return VP8_STATUS_OK; // Found. |
| 205 | } |
| 206 | |
| 207 | // We have a full and valid chunk; skip it. |
| 208 | buf += disk_chunk_size; |
| 209 | buf_size -= disk_chunk_size; |
| 210 | } |
| 211 | } |
| 212 | |
| 213 | // Validates the VP8/VP8L Header ("VP8 nnnn" or "VP8L nnnn") and skips over it. |
| 214 | // Returns VP8_STATUS_BITSTREAM_ERROR for invalid (chunk larger than |
| 215 | // riff_size) VP8/VP8L header, |
| 216 | // VP8_STATUS_NOT_ENOUGH_DATA in case of insufficient data, and |
| 217 | // VP8_STATUS_OK otherwise. |
| 218 | // If a VP8/VP8L chunk is found, *chunk_size is set to the total number of bytes |
| 219 | // extracted from the VP8/VP8L chunk header. |
| 220 | // The flag '*is_lossless' is set to 1 in case of VP8L chunk / raw VP8L data. |
| 221 | static VP8StatusCode ParseVP8Header(const uint8_t** const data_ptr, |
| 222 | size_t* const data_size, |
| 223 | size_t riff_size, |
| 224 | size_t* const chunk_size, |
| 225 | int* const is_lossless) { |
| 226 | const uint8_t* const data = *data_ptr; |
| 227 | const int is_vp8 = !memcmp(data, "VP8 ", TAG_SIZE); |
| 228 | const int is_vp8l = !memcmp(data, "VP8L", TAG_SIZE); |
| 229 | const uint32_t minimal_size = |
| 230 | TAG_SIZE + CHUNK_HEADER_SIZE; // "WEBP" + "VP8 nnnn" OR |
| 231 | // "WEBP" + "VP8Lnnnn" |
| 232 | assert(data != NULL); |
| 233 | assert(data_size != NULL); |
| 234 | assert(chunk_size != NULL); |
| 235 | assert(is_lossless != NULL); |
| 236 | |
| 237 | if (*data_size < CHUNK_HEADER_SIZE) { |
| 238 | return VP8_STATUS_NOT_ENOUGH_DATA; // Insufficient data. |
| 239 | } |
| 240 | |
| 241 | if (is_vp8 || is_vp8l) { |
| 242 | // Bitstream contains VP8/VP8L header. |
| 243 | const uint32_t size = get_le32(data + TAG_SIZE); |
| 244 | if ((riff_size >= minimal_size) && (size > riff_size - minimal_size)) { |
| 245 | return VP8_STATUS_BITSTREAM_ERROR; // Inconsistent size information. |
| 246 | } |
| 247 | // Skip over CHUNK_HEADER_SIZE bytes from VP8/VP8L Header. |
| 248 | *chunk_size = size; |
| 249 | *data_ptr += CHUNK_HEADER_SIZE; |
| 250 | *data_size -= CHUNK_HEADER_SIZE; |
| 251 | *is_lossless = is_vp8l; |
| 252 | } else { |
| 253 | // Raw VP8/VP8L bitstream (no header). |
| 254 | *is_lossless = VP8LCheckSignature(data, *data_size); |
| 255 | *chunk_size = *data_size; |
| 256 | } |
| 257 | |
| 258 | return VP8_STATUS_OK; |
| 259 | } |
| 260 | |
| 261 | //------------------------------------------------------------------------------ |
| 262 | |
| 263 | // Fetch '*width', '*height', '*has_alpha' and fill out 'headers' based on |
| 264 | // 'data'. All the output parameters may be NULL. If 'headers' is NULL only the |
| 265 | // minimal amount will be read to fetch the remaining parameters. |
| 266 | // If 'headers' is non-NULL this function will attempt to locate both alpha |
| 267 | // data (with or without a VP8X chunk) and the bitstream chunk (VP8/VP8L). |
| 268 | // Note: The following chunk sequences (before the raw VP8/VP8L data) are |
| 269 | // considered valid by this function: |
| 270 | // RIFF + VP8(L) |
| 271 | // RIFF + VP8X + (optional chunks) + VP8(L) |
| 272 | // ALPH + VP8 <-- Not a valid WebP format: only allowed for internal purpose. |
| 273 | // VP8(L) <-- Not a valid WebP format: only allowed for internal purpose. |
| 274 | static VP8StatusCode ParseHeadersInternal(const uint8_t* data, |
| 275 | size_t data_size, |
| 276 | int* const width, |
| 277 | int* const height, |
| 278 | int* const has_alpha, |
| 279 | WebPHeaderStructure* const headers) { |
| 280 | int found_riff = 0; |
| 281 | int found_vp8x = 0; |
| 282 | VP8StatusCode status; |
| 283 | WebPHeaderStructure hdrs; |
| 284 | |
| 285 | if (data == NULL || data_size < RIFF_HEADER_SIZE) { |
| 286 | return VP8_STATUS_NOT_ENOUGH_DATA; |
| 287 | } |
| 288 | memset(&hdrs, 0, sizeof(hdrs)); |
| 289 | hdrs.data = data; |
| 290 | hdrs.data_size = data_size; |
| 291 | |
| 292 | // Skip over RIFF header. |
| 293 | status = ParseRIFF(&data, &data_size, &hdrs.riff_size); |
| 294 | if (status != VP8_STATUS_OK) { |
| 295 | return status; // Wrong RIFF header / insufficient data. |
| 296 | } |
| 297 | found_riff = (hdrs.riff_size > 0); |
| 298 | |
| 299 | // Skip over VP8X. |
| 300 | { |
| 301 | uint32_t flags = 0; |
| 302 | status = ParseVP8X(&data, &data_size, &found_vp8x, width, height, &flags); |
| 303 | if (status != VP8_STATUS_OK) { |
| 304 | return status; // Wrong VP8X / insufficient data. |
| 305 | } |
| 306 | if (!found_riff && found_vp8x) { |
| 307 | // Note: This restriction may be removed in the future, if it becomes |
| 308 | // necessary to send VP8X chunk to the decoder. |
| 309 | return VP8_STATUS_BITSTREAM_ERROR; |
| 310 | } |
Vikas Arora | 1e7bf88 | 2013-03-13 16:43:18 -0700 | [diff] [blame^] | 311 | if (has_alpha != NULL) *has_alpha = !!(flags & ALPHA_FLAG); |
Vikas Arora | a241572 | 2012-08-09 16:18:58 -0700 | [diff] [blame] | 312 | if (found_vp8x && headers == NULL) { |
| 313 | return VP8_STATUS_OK; // Return features from VP8X header. |
| 314 | } |
| 315 | } |
| 316 | |
| 317 | if (data_size < TAG_SIZE) return VP8_STATUS_NOT_ENOUGH_DATA; |
| 318 | |
| 319 | // Skip over optional chunks if data started with "RIFF + VP8X" or "ALPH". |
| 320 | if ((found_riff && found_vp8x) || |
| 321 | (!found_riff && !found_vp8x && !memcmp(data, "ALPH", TAG_SIZE))) { |
| 322 | status = ParseOptionalChunks(&data, &data_size, hdrs.riff_size, |
| 323 | &hdrs.alpha_data, &hdrs.alpha_data_size); |
| 324 | if (status != VP8_STATUS_OK) { |
| 325 | return status; // Found an invalid chunk size / insufficient data. |
| 326 | } |
| 327 | } |
| 328 | |
| 329 | // Skip over VP8/VP8L header. |
| 330 | status = ParseVP8Header(&data, &data_size, hdrs.riff_size, |
| 331 | &hdrs.compressed_size, &hdrs.is_lossless); |
| 332 | if (status != VP8_STATUS_OK) { |
| 333 | return status; // Wrong VP8/VP8L chunk-header / insufficient data. |
| 334 | } |
| 335 | if (hdrs.compressed_size > MAX_CHUNK_PAYLOAD) { |
| 336 | return VP8_STATUS_BITSTREAM_ERROR; |
| 337 | } |
| 338 | |
| 339 | if (!hdrs.is_lossless) { |
| 340 | if (data_size < VP8_FRAME_HEADER_SIZE) { |
| 341 | return VP8_STATUS_NOT_ENOUGH_DATA; |
| 342 | } |
| 343 | // Validates raw VP8 data. |
| 344 | if (!VP8GetInfo(data, data_size, |
| 345 | (uint32_t)hdrs.compressed_size, width, height)) { |
| 346 | return VP8_STATUS_BITSTREAM_ERROR; |
| 347 | } |
| 348 | } else { |
| 349 | if (data_size < VP8L_FRAME_HEADER_SIZE) { |
| 350 | return VP8_STATUS_NOT_ENOUGH_DATA; |
| 351 | } |
| 352 | // Validates raw VP8L data. |
| 353 | if (!VP8LGetInfo(data, data_size, width, height, has_alpha)) { |
| 354 | return VP8_STATUS_BITSTREAM_ERROR; |
| 355 | } |
| 356 | } |
| 357 | |
| 358 | if (has_alpha != NULL) { |
| 359 | // If the data did not contain a VP8X/VP8L chunk the only definitive way |
| 360 | // to set this is by looking for alpha data (from an ALPH chunk). |
| 361 | *has_alpha |= (hdrs.alpha_data != NULL); |
| 362 | } |
| 363 | if (headers != NULL) { |
| 364 | *headers = hdrs; |
| 365 | headers->offset = data - headers->data; |
| 366 | assert((uint64_t)(data - headers->data) < MAX_CHUNK_PAYLOAD); |
| 367 | assert(headers->offset == headers->data_size - data_size); |
| 368 | } |
| 369 | return VP8_STATUS_OK; // Return features from VP8 header. |
| 370 | } |
| 371 | |
| 372 | VP8StatusCode WebPParseHeaders(WebPHeaderStructure* const headers) { |
| 373 | assert(headers != NULL); |
| 374 | // fill out headers, ignore width/height/has_alpha. |
| 375 | return ParseHeadersInternal(headers->data, headers->data_size, |
| 376 | NULL, NULL, NULL, headers); |
| 377 | } |
| 378 | |
| 379 | //------------------------------------------------------------------------------ |
Vikas Arora | 4667279 | 2011-07-13 16:37:55 +0530 | [diff] [blame] | 380 | // WebPDecParams |
Eric Hassold | 9aea642 | 2011-01-04 17:22:46 -0800 | [diff] [blame] | 381 | |
Vikas Arora | 4667279 | 2011-07-13 16:37:55 +0530 | [diff] [blame] | 382 | void WebPResetDecParams(WebPDecParams* const params) { |
| 383 | if (params) { |
| 384 | memset(params, 0, sizeof(*params)); |
Eric Hassold | 9aea642 | 2011-01-04 17:22:46 -0800 | [diff] [blame] | 385 | } |
| 386 | } |
| 387 | |
Vikas Arora | a241572 | 2012-08-09 16:18:58 -0700 | [diff] [blame] | 388 | //------------------------------------------------------------------------------ |
Vikas Arora | 4667279 | 2011-07-13 16:37:55 +0530 | [diff] [blame] | 389 | // "Into" decoding variants |
Eric Hassold | 9aea642 | 2011-01-04 17:22:46 -0800 | [diff] [blame] | 390 | |
Vikas Arora | 4667279 | 2011-07-13 16:37:55 +0530 | [diff] [blame] | 391 | // Main flow |
Vikas Arora | a241572 | 2012-08-09 16:18:58 -0700 | [diff] [blame] | 392 | static VP8StatusCode DecodeInto(const uint8_t* const data, size_t data_size, |
Vikas Arora | 4667279 | 2011-07-13 16:37:55 +0530 | [diff] [blame] | 393 | WebPDecParams* const params) { |
Vikas Arora | a241572 | 2012-08-09 16:18:58 -0700 | [diff] [blame] | 394 | VP8StatusCode status; |
Eric Hassold | 9aea642 | 2011-01-04 17:22:46 -0800 | [diff] [blame] | 395 | VP8Io io; |
Vikas Arora | a241572 | 2012-08-09 16:18:58 -0700 | [diff] [blame] | 396 | WebPHeaderStructure headers; |
Eric Hassold | 9aea642 | 2011-01-04 17:22:46 -0800 | [diff] [blame] | 397 | |
Vikas Arora | a241572 | 2012-08-09 16:18:58 -0700 | [diff] [blame] | 398 | headers.data = data; |
| 399 | headers.data_size = data_size; |
| 400 | status = WebPParseHeaders(&headers); // Process Pre-VP8 chunks. |
| 401 | if (status != VP8_STATUS_OK) { |
| 402 | return status; |
Eric Hassold | 9aea642 | 2011-01-04 17:22:46 -0800 | [diff] [blame] | 403 | } |
| 404 | |
Vikas Arora | a241572 | 2012-08-09 16:18:58 -0700 | [diff] [blame] | 405 | assert(params != NULL); |
Eric Hassold | 9aea642 | 2011-01-04 17:22:46 -0800 | [diff] [blame] | 406 | VP8InitIo(&io); |
Vikas Arora | a241572 | 2012-08-09 16:18:58 -0700 | [diff] [blame] | 407 | io.data = headers.data + headers.offset; |
| 408 | io.data_size = headers.data_size - headers.offset; |
Vikas Arora | 4667279 | 2011-07-13 16:37:55 +0530 | [diff] [blame] | 409 | WebPInitCustomIo(params, &io); // Plug the I/O functions. |
Eric Hassold | 9aea642 | 2011-01-04 17:22:46 -0800 | [diff] [blame] | 410 | |
Vikas Arora | a241572 | 2012-08-09 16:18:58 -0700 | [diff] [blame] | 411 | if (!headers.is_lossless) { |
| 412 | VP8Decoder* const dec = VP8New(); |
| 413 | if (dec == NULL) { |
| 414 | return VP8_STATUS_OUT_OF_MEMORY; |
| 415 | } |
| 416 | #ifdef WEBP_USE_THREAD |
| 417 | dec->use_threads_ = params->options && (params->options->use_threads > 0); |
| 418 | #else |
| 419 | dec->use_threads_ = 0; |
| 420 | #endif |
| 421 | dec->alpha_data_ = headers.alpha_data; |
| 422 | dec->alpha_data_size_ = headers.alpha_data_size; |
| 423 | |
| 424 | // Decode bitstream header, update io->width/io->height. |
| 425 | if (!VP8GetHeaders(dec, &io)) { |
| 426 | status = dec->status_; // An error occurred. Grab error status. |
| 427 | } else { |
| 428 | // Allocate/check output buffers. |
| 429 | status = WebPAllocateDecBuffer(io.width, io.height, params->options, |
| 430 | params->output); |
| 431 | if (status == VP8_STATUS_OK) { // Decode |
| 432 | if (!VP8Decode(dec, &io)) { |
| 433 | status = dec->status_; |
| 434 | } |
Vikas Arora | 4667279 | 2011-07-13 16:37:55 +0530 | [diff] [blame] | 435 | } |
| 436 | } |
Vikas Arora | a241572 | 2012-08-09 16:18:58 -0700 | [diff] [blame] | 437 | VP8Delete(dec); |
| 438 | } else { |
| 439 | VP8LDecoder* const dec = VP8LNew(); |
| 440 | if (dec == NULL) { |
| 441 | return VP8_STATUS_OUT_OF_MEMORY; |
| 442 | } |
| 443 | if (!VP8LDecodeHeader(dec, &io)) { |
| 444 | status = dec->status_; // An error occurred. Grab error status. |
| 445 | } else { |
| 446 | // Allocate/check output buffers. |
| 447 | status = WebPAllocateDecBuffer(io.width, io.height, params->options, |
| 448 | params->output); |
| 449 | if (status == VP8_STATUS_OK) { // Decode |
| 450 | if (!VP8LDecodeImage(dec)) { |
| 451 | status = dec->status_; |
| 452 | } |
| 453 | } |
| 454 | } |
| 455 | VP8LDelete(dec); |
Eric Hassold | 9aea642 | 2011-01-04 17:22:46 -0800 | [diff] [blame] | 456 | } |
Vikas Arora | a241572 | 2012-08-09 16:18:58 -0700 | [diff] [blame] | 457 | |
Vikas Arora | 4667279 | 2011-07-13 16:37:55 +0530 | [diff] [blame] | 458 | if (status != VP8_STATUS_OK) { |
| 459 | WebPFreeDecBuffer(params->output); |
| 460 | } |
| 461 | return status; |
| 462 | } |
| 463 | |
| 464 | // Helpers |
| 465 | static uint8_t* DecodeIntoRGBABuffer(WEBP_CSP_MODE colorspace, |
Vikas Arora | a241572 | 2012-08-09 16:18:58 -0700 | [diff] [blame] | 466 | const uint8_t* const data, |
| 467 | size_t data_size, |
| 468 | uint8_t* const rgba, |
| 469 | int stride, size_t size) { |
Vikas Arora | 4667279 | 2011-07-13 16:37:55 +0530 | [diff] [blame] | 470 | WebPDecParams params; |
| 471 | WebPDecBuffer buf; |
| 472 | if (rgba == NULL) { |
| 473 | return NULL; |
| 474 | } |
| 475 | WebPInitDecBuffer(&buf); |
| 476 | WebPResetDecParams(¶ms); |
| 477 | params.output = &buf; |
| 478 | buf.colorspace = colorspace; |
| 479 | buf.u.RGBA.rgba = rgba; |
| 480 | buf.u.RGBA.stride = stride; |
| 481 | buf.u.RGBA.size = size; |
| 482 | buf.is_external_memory = 1; |
| 483 | if (DecodeInto(data, data_size, ¶ms) != VP8_STATUS_OK) { |
| 484 | return NULL; |
| 485 | } |
| 486 | return rgba; |
Eric Hassold | 9aea642 | 2011-01-04 17:22:46 -0800 | [diff] [blame] | 487 | } |
| 488 | |
Vikas Arora | a241572 | 2012-08-09 16:18:58 -0700 | [diff] [blame] | 489 | uint8_t* WebPDecodeRGBInto(const uint8_t* data, size_t data_size, |
| 490 | uint8_t* output, size_t size, int stride) { |
Vikas Arora | 4667279 | 2011-07-13 16:37:55 +0530 | [diff] [blame] | 491 | return DecodeIntoRGBABuffer(MODE_RGB, data, data_size, output, stride, size); |
Eric Hassold | 9aea642 | 2011-01-04 17:22:46 -0800 | [diff] [blame] | 492 | } |
| 493 | |
Vikas Arora | a241572 | 2012-08-09 16:18:58 -0700 | [diff] [blame] | 494 | uint8_t* WebPDecodeRGBAInto(const uint8_t* data, size_t data_size, |
| 495 | uint8_t* output, size_t size, int stride) { |
Vikas Arora | 4667279 | 2011-07-13 16:37:55 +0530 | [diff] [blame] | 496 | return DecodeIntoRGBABuffer(MODE_RGBA, data, data_size, output, stride, size); |
| 497 | } |
Eric Hassold | 9aea642 | 2011-01-04 17:22:46 -0800 | [diff] [blame] | 498 | |
Vikas Arora | a241572 | 2012-08-09 16:18:58 -0700 | [diff] [blame] | 499 | uint8_t* WebPDecodeARGBInto(const uint8_t* data, size_t data_size, |
| 500 | uint8_t* output, size_t size, int stride) { |
Vikas Arora | 4667279 | 2011-07-13 16:37:55 +0530 | [diff] [blame] | 501 | return DecodeIntoRGBABuffer(MODE_ARGB, data, data_size, output, stride, size); |
Eric Hassold | 9aea642 | 2011-01-04 17:22:46 -0800 | [diff] [blame] | 502 | } |
| 503 | |
Vikas Arora | a241572 | 2012-08-09 16:18:58 -0700 | [diff] [blame] | 504 | uint8_t* WebPDecodeBGRInto(const uint8_t* data, size_t data_size, |
| 505 | uint8_t* output, size_t size, int stride) { |
Vikas Arora | 4667279 | 2011-07-13 16:37:55 +0530 | [diff] [blame] | 506 | return DecodeIntoRGBABuffer(MODE_BGR, data, data_size, output, stride, size); |
Eric Hassold | 9aea642 | 2011-01-04 17:22:46 -0800 | [diff] [blame] | 507 | } |
| 508 | |
Vikas Arora | a241572 | 2012-08-09 16:18:58 -0700 | [diff] [blame] | 509 | uint8_t* WebPDecodeBGRAInto(const uint8_t* data, size_t data_size, |
| 510 | uint8_t* output, size_t size, int stride) { |
Vikas Arora | 4667279 | 2011-07-13 16:37:55 +0530 | [diff] [blame] | 511 | return DecodeIntoRGBABuffer(MODE_BGRA, data, data_size, output, stride, size); |
Eric Hassold | 9aea642 | 2011-01-04 17:22:46 -0800 | [diff] [blame] | 512 | } |
| 513 | |
Vikas Arora | a241572 | 2012-08-09 16:18:58 -0700 | [diff] [blame] | 514 | uint8_t* WebPDecodeYUVInto(const uint8_t* data, size_t data_size, |
| 515 | uint8_t* luma, size_t luma_size, int luma_stride, |
| 516 | uint8_t* u, size_t u_size, int u_stride, |
| 517 | uint8_t* v, size_t v_size, int v_stride) { |
Vikas Arora | 03d5e34 | 2011-06-02 23:59:44 +0530 | [diff] [blame] | 518 | WebPDecParams params; |
Vikas Arora | 4667279 | 2011-07-13 16:37:55 +0530 | [diff] [blame] | 519 | WebPDecBuffer output; |
| 520 | if (luma == NULL) return NULL; |
| 521 | WebPInitDecBuffer(&output); |
| 522 | WebPResetDecParams(¶ms); |
| 523 | params.output = &output; |
| 524 | output.colorspace = MODE_YUV; |
| 525 | output.u.YUVA.y = luma; |
| 526 | output.u.YUVA.y_stride = luma_stride; |
| 527 | output.u.YUVA.y_size = luma_size; |
| 528 | output.u.YUVA.u = u; |
| 529 | output.u.YUVA.u_stride = u_stride; |
| 530 | output.u.YUVA.u_size = u_size; |
| 531 | output.u.YUVA.v = v; |
| 532 | output.u.YUVA.v_stride = v_stride; |
| 533 | output.u.YUVA.v_size = v_size; |
| 534 | output.is_external_memory = 1; |
| 535 | if (DecodeInto(data, data_size, ¶ms) != VP8_STATUS_OK) { |
Eric Hassold | 9aea642 | 2011-01-04 17:22:46 -0800 | [diff] [blame] | 536 | return NULL; |
| 537 | } |
Vikas Arora | 4667279 | 2011-07-13 16:37:55 +0530 | [diff] [blame] | 538 | return luma; |
Eric Hassold | 9aea642 | 2011-01-04 17:22:46 -0800 | [diff] [blame] | 539 | } |
| 540 | |
Vikas Arora | a241572 | 2012-08-09 16:18:58 -0700 | [diff] [blame] | 541 | //------------------------------------------------------------------------------ |
Eric Hassold | 9aea642 | 2011-01-04 17:22:46 -0800 | [diff] [blame] | 542 | |
Vikas Arora | a241572 | 2012-08-09 16:18:58 -0700 | [diff] [blame] | 543 | static uint8_t* Decode(WEBP_CSP_MODE mode, const uint8_t* const data, |
| 544 | size_t data_size, int* const width, int* const height, |
| 545 | WebPDecBuffer* const keep_info) { |
Vikas Arora | 03d5e34 | 2011-06-02 23:59:44 +0530 | [diff] [blame] | 546 | WebPDecParams params; |
Vikas Arora | 4667279 | 2011-07-13 16:37:55 +0530 | [diff] [blame] | 547 | WebPDecBuffer output; |
Eric Hassold | 9aea642 | 2011-01-04 17:22:46 -0800 | [diff] [blame] | 548 | |
Vikas Arora | 4667279 | 2011-07-13 16:37:55 +0530 | [diff] [blame] | 549 | WebPInitDecBuffer(&output); |
| 550 | WebPResetDecParams(¶ms); |
| 551 | params.output = &output; |
| 552 | output.colorspace = mode; |
| 553 | |
| 554 | // Retrieve (and report back) the required dimensions from bitstream. |
| 555 | if (!WebPGetInfo(data, data_size, &output.width, &output.height)) { |
Eric Hassold | 9aea642 | 2011-01-04 17:22:46 -0800 | [diff] [blame] | 556 | return NULL; |
| 557 | } |
Vikas Arora | a241572 | 2012-08-09 16:18:58 -0700 | [diff] [blame] | 558 | if (width != NULL) *width = output.width; |
| 559 | if (height != NULL) *height = output.height; |
Eric Hassold | 9aea642 | 2011-01-04 17:22:46 -0800 | [diff] [blame] | 560 | |
Vikas Arora | 4667279 | 2011-07-13 16:37:55 +0530 | [diff] [blame] | 561 | // Decode |
| 562 | if (DecodeInto(data, data_size, ¶ms) != VP8_STATUS_OK) { |
| 563 | return NULL; |
Eric Hassold | 9aea642 | 2011-01-04 17:22:46 -0800 | [diff] [blame] | 564 | } |
Vikas Arora | a241572 | 2012-08-09 16:18:58 -0700 | [diff] [blame] | 565 | if (keep_info != NULL) { // keep track of the side-info |
Vikas Arora | 4667279 | 2011-07-13 16:37:55 +0530 | [diff] [blame] | 566 | WebPCopyDecBuffer(&output, keep_info); |
Eric Hassold | 9aea642 | 2011-01-04 17:22:46 -0800 | [diff] [blame] | 567 | } |
Vikas Arora | 4667279 | 2011-07-13 16:37:55 +0530 | [diff] [blame] | 568 | // return decoded samples (don't clear 'output'!) |
Vikas Arora | a241572 | 2012-08-09 16:18:58 -0700 | [diff] [blame] | 569 | return WebPIsRGBMode(mode) ? output.u.RGBA.rgba : output.u.YUVA.y; |
Eric Hassold | 9aea642 | 2011-01-04 17:22:46 -0800 | [diff] [blame] | 570 | } |
| 571 | |
Vikas Arora | a241572 | 2012-08-09 16:18:58 -0700 | [diff] [blame] | 572 | uint8_t* WebPDecodeRGB(const uint8_t* data, size_t data_size, |
Vikas Arora | 4667279 | 2011-07-13 16:37:55 +0530 | [diff] [blame] | 573 | int* width, int* height) { |
Eric Hassold | 9aea642 | 2011-01-04 17:22:46 -0800 | [diff] [blame] | 574 | return Decode(MODE_RGB, data, data_size, width, height, NULL); |
| 575 | } |
| 576 | |
Vikas Arora | a241572 | 2012-08-09 16:18:58 -0700 | [diff] [blame] | 577 | uint8_t* WebPDecodeRGBA(const uint8_t* data, size_t data_size, |
Vikas Arora | 4667279 | 2011-07-13 16:37:55 +0530 | [diff] [blame] | 578 | int* width, int* height) { |
Eric Hassold | 9aea642 | 2011-01-04 17:22:46 -0800 | [diff] [blame] | 579 | return Decode(MODE_RGBA, data, data_size, width, height, NULL); |
| 580 | } |
| 581 | |
Vikas Arora | a241572 | 2012-08-09 16:18:58 -0700 | [diff] [blame] | 582 | uint8_t* WebPDecodeARGB(const uint8_t* data, size_t data_size, |
Vikas Arora | 4667279 | 2011-07-13 16:37:55 +0530 | [diff] [blame] | 583 | int* width, int* height) { |
| 584 | return Decode(MODE_ARGB, data, data_size, width, height, NULL); |
| 585 | } |
| 586 | |
Vikas Arora | a241572 | 2012-08-09 16:18:58 -0700 | [diff] [blame] | 587 | uint8_t* WebPDecodeBGR(const uint8_t* data, size_t data_size, |
Vikas Arora | 4667279 | 2011-07-13 16:37:55 +0530 | [diff] [blame] | 588 | int* width, int* height) { |
Eric Hassold | 9aea642 | 2011-01-04 17:22:46 -0800 | [diff] [blame] | 589 | return Decode(MODE_BGR, data, data_size, width, height, NULL); |
| 590 | } |
| 591 | |
Vikas Arora | a241572 | 2012-08-09 16:18:58 -0700 | [diff] [blame] | 592 | uint8_t* WebPDecodeBGRA(const uint8_t* data, size_t data_size, |
Vikas Arora | 4667279 | 2011-07-13 16:37:55 +0530 | [diff] [blame] | 593 | int* width, int* height) { |
Eric Hassold | 9aea642 | 2011-01-04 17:22:46 -0800 | [diff] [blame] | 594 | return Decode(MODE_BGRA, data, data_size, width, height, NULL); |
| 595 | } |
| 596 | |
Vikas Arora | a241572 | 2012-08-09 16:18:58 -0700 | [diff] [blame] | 597 | uint8_t* WebPDecodeYUV(const uint8_t* data, size_t data_size, |
Vikas Arora | 4667279 | 2011-07-13 16:37:55 +0530 | [diff] [blame] | 598 | int* width, int* height, uint8_t** u, uint8_t** v, |
| 599 | int* stride, int* uv_stride) { |
| 600 | WebPDecBuffer output; // only to preserve the side-infos |
Eric Hassold | 9aea642 | 2011-01-04 17:22:46 -0800 | [diff] [blame] | 601 | uint8_t* const out = Decode(MODE_YUV, data, data_size, |
Vikas Arora | 4667279 | 2011-07-13 16:37:55 +0530 | [diff] [blame] | 602 | width, height, &output); |
Eric Hassold | 9aea642 | 2011-01-04 17:22:46 -0800 | [diff] [blame] | 603 | |
Vikas Arora | a241572 | 2012-08-09 16:18:58 -0700 | [diff] [blame] | 604 | if (out != NULL) { |
Vikas Arora | 4667279 | 2011-07-13 16:37:55 +0530 | [diff] [blame] | 605 | const WebPYUVABuffer* const buf = &output.u.YUVA; |
| 606 | *u = buf->u; |
| 607 | *v = buf->v; |
| 608 | *stride = buf->y_stride; |
| 609 | *uv_stride = buf->u_stride; |
| 610 | assert(buf->u_stride == buf->v_stride); |
Eric Hassold | 9aea642 | 2011-01-04 17:22:46 -0800 | [diff] [blame] | 611 | } |
| 612 | return out; |
| 613 | } |
| 614 | |
Vikas Arora | 4667279 | 2011-07-13 16:37:55 +0530 | [diff] [blame] | 615 | static void DefaultFeatures(WebPBitstreamFeatures* const features) { |
Vikas Arora | a241572 | 2012-08-09 16:18:58 -0700 | [diff] [blame] | 616 | assert(features != NULL); |
Vikas Arora | 4667279 | 2011-07-13 16:37:55 +0530 | [diff] [blame] | 617 | memset(features, 0, sizeof(*features)); |
| 618 | features->bitstream_version = 0; |
| 619 | } |
| 620 | |
Vikas Arora | a241572 | 2012-08-09 16:18:58 -0700 | [diff] [blame] | 621 | static VP8StatusCode GetFeatures(const uint8_t* const data, size_t data_size, |
Vikas Arora | 4667279 | 2011-07-13 16:37:55 +0530 | [diff] [blame] | 622 | WebPBitstreamFeatures* const features) { |
Vikas Arora | a241572 | 2012-08-09 16:18:58 -0700 | [diff] [blame] | 623 | if (features == NULL || data == NULL) { |
Vikas Arora | 4667279 | 2011-07-13 16:37:55 +0530 | [diff] [blame] | 624 | return VP8_STATUS_INVALID_PARAM; |
Eric Hassold | 9aea642 | 2011-01-04 17:22:46 -0800 | [diff] [blame] | 625 | } |
Vikas Arora | 4667279 | 2011-07-13 16:37:55 +0530 | [diff] [blame] | 626 | DefaultFeatures(features); |
Vikas Arora | a241572 | 2012-08-09 16:18:58 -0700 | [diff] [blame] | 627 | |
| 628 | // Only parse enough of the data to retrieve width/height/has_alpha. |
| 629 | return ParseHeadersInternal(data, data_size, |
| 630 | &features->width, &features->height, |
| 631 | &features->has_alpha, NULL); |
Vikas Arora | 4667279 | 2011-07-13 16:37:55 +0530 | [diff] [blame] | 632 | } |
| 633 | |
Vikas Arora | a241572 | 2012-08-09 16:18:58 -0700 | [diff] [blame] | 634 | //------------------------------------------------------------------------------ |
| 635 | // WebPGetInfo() |
| 636 | |
| 637 | int WebPGetInfo(const uint8_t* data, size_t data_size, |
| 638 | int* width, int* height) { |
| 639 | WebPBitstreamFeatures features; |
| 640 | |
| 641 | if (GetFeatures(data, data_size, &features) != VP8_STATUS_OK) { |
| 642 | return 0; |
| 643 | } |
| 644 | |
| 645 | if (width != NULL) { |
| 646 | *width = features.width; |
| 647 | } |
| 648 | if (height != NULL) { |
| 649 | *height = features.height; |
| 650 | } |
| 651 | |
| 652 | return 1; |
| 653 | } |
| 654 | |
| 655 | //------------------------------------------------------------------------------ |
Vikas Arora | 4667279 | 2011-07-13 16:37:55 +0530 | [diff] [blame] | 656 | // Advance decoding API |
| 657 | |
Vikas Arora | a241572 | 2012-08-09 16:18:58 -0700 | [diff] [blame] | 658 | int WebPInitDecoderConfigInternal(WebPDecoderConfig* config, |
Vikas Arora | 4667279 | 2011-07-13 16:37:55 +0530 | [diff] [blame] | 659 | int version) { |
Vikas Arora | a241572 | 2012-08-09 16:18:58 -0700 | [diff] [blame] | 660 | if (WEBP_ABI_IS_INCOMPATIBLE(version, WEBP_DECODER_ABI_VERSION)) { |
Vikas Arora | 4667279 | 2011-07-13 16:37:55 +0530 | [diff] [blame] | 661 | return 0; // version mismatch |
| 662 | } |
| 663 | if (config == NULL) { |
| 664 | return 0; |
| 665 | } |
| 666 | memset(config, 0, sizeof(*config)); |
| 667 | DefaultFeatures(&config->input); |
| 668 | WebPInitDecBuffer(&config->output); |
| 669 | return 1; |
| 670 | } |
| 671 | |
Vikas Arora | a241572 | 2012-08-09 16:18:58 -0700 | [diff] [blame] | 672 | VP8StatusCode WebPGetFeaturesInternal(const uint8_t* data, size_t data_size, |
| 673 | WebPBitstreamFeatures* features, |
| 674 | int version) { |
Vikas Arora | a241572 | 2012-08-09 16:18:58 -0700 | [diff] [blame] | 675 | if (WEBP_ABI_IS_INCOMPATIBLE(version, WEBP_DECODER_ABI_VERSION)) { |
Vikas Arora | 4667279 | 2011-07-13 16:37:55 +0530 | [diff] [blame] | 676 | return VP8_STATUS_INVALID_PARAM; // version mismatch |
| 677 | } |
| 678 | if (features == NULL) { |
| 679 | return VP8_STATUS_INVALID_PARAM; |
| 680 | } |
Vikas Arora | 1e7bf88 | 2013-03-13 16:43:18 -0700 | [diff] [blame^] | 681 | return GetFeatures(data, data_size, features); |
Vikas Arora | 4667279 | 2011-07-13 16:37:55 +0530 | [diff] [blame] | 682 | } |
| 683 | |
Vikas Arora | a241572 | 2012-08-09 16:18:58 -0700 | [diff] [blame] | 684 | VP8StatusCode WebPDecode(const uint8_t* data, size_t data_size, |
| 685 | WebPDecoderConfig* config) { |
Vikas Arora | 4667279 | 2011-07-13 16:37:55 +0530 | [diff] [blame] | 686 | WebPDecParams params; |
| 687 | VP8StatusCode status; |
| 688 | |
Vikas Arora | a241572 | 2012-08-09 16:18:58 -0700 | [diff] [blame] | 689 | if (config == NULL) { |
Vikas Arora | 4667279 | 2011-07-13 16:37:55 +0530 | [diff] [blame] | 690 | return VP8_STATUS_INVALID_PARAM; |
| 691 | } |
| 692 | |
Vikas Arora | a241572 | 2012-08-09 16:18:58 -0700 | [diff] [blame] | 693 | status = GetFeatures(data, data_size, &config->input); |
Vikas Arora | 4667279 | 2011-07-13 16:37:55 +0530 | [diff] [blame] | 694 | if (status != VP8_STATUS_OK) { |
Vikas Arora | a241572 | 2012-08-09 16:18:58 -0700 | [diff] [blame] | 695 | if (status == VP8_STATUS_NOT_ENOUGH_DATA) { |
| 696 | return VP8_STATUS_BITSTREAM_ERROR; // Not-enough-data treated as error. |
| 697 | } |
Vikas Arora | 4667279 | 2011-07-13 16:37:55 +0530 | [diff] [blame] | 698 | return status; |
| 699 | } |
| 700 | |
| 701 | WebPResetDecParams(¶ms); |
| 702 | params.output = &config->output; |
| 703 | params.options = &config->options; |
| 704 | status = DecodeInto(data, data_size, ¶ms); |
| 705 | |
| 706 | return status; |
Eric Hassold | 9aea642 | 2011-01-04 17:22:46 -0800 | [diff] [blame] | 707 | } |
| 708 | |
Vikas Arora | a241572 | 2012-08-09 16:18:58 -0700 | [diff] [blame] | 709 | //------------------------------------------------------------------------------ |
| 710 | // Cropping and rescaling. |
| 711 | |
| 712 | int WebPIoInitFromOptions(const WebPDecoderOptions* const options, |
| 713 | VP8Io* const io, WEBP_CSP_MODE src_colorspace) { |
| 714 | const int W = io->width; |
| 715 | const int H = io->height; |
| 716 | int x = 0, y = 0, w = W, h = H; |
| 717 | |
| 718 | // Cropping |
| 719 | io->use_cropping = (options != NULL) && (options->use_cropping > 0); |
| 720 | if (io->use_cropping) { |
| 721 | w = options->crop_width; |
| 722 | h = options->crop_height; |
| 723 | x = options->crop_left; |
| 724 | y = options->crop_top; |
| 725 | if (!WebPIsRGBMode(src_colorspace)) { // only snap for YUV420 or YUV422 |
| 726 | x &= ~1; |
| 727 | y &= ~1; // TODO(later): only for YUV420, not YUV422. |
| 728 | } |
| 729 | if (x < 0 || y < 0 || w <= 0 || h <= 0 || x + w > W || y + h > H) { |
| 730 | return 0; // out of frame boundary error |
| 731 | } |
| 732 | } |
| 733 | io->crop_left = x; |
| 734 | io->crop_top = y; |
| 735 | io->crop_right = x + w; |
| 736 | io->crop_bottom = y + h; |
| 737 | io->mb_w = w; |
| 738 | io->mb_h = h; |
| 739 | |
| 740 | // Scaling |
| 741 | io->use_scaling = (options != NULL) && (options->use_scaling > 0); |
| 742 | if (io->use_scaling) { |
| 743 | if (options->scaled_width <= 0 || options->scaled_height <= 0) { |
| 744 | return 0; |
| 745 | } |
| 746 | io->scaled_width = options->scaled_width; |
| 747 | io->scaled_height = options->scaled_height; |
| 748 | } |
| 749 | |
| 750 | // Filter |
| 751 | io->bypass_filtering = options && options->bypass_filtering; |
| 752 | |
| 753 | // Fancy upsampler |
| 754 | #ifdef FANCY_UPSAMPLING |
| 755 | io->fancy_upsampling = (options == NULL) || (!options->no_fancy_upsampling); |
| 756 | #endif |
| 757 | |
| 758 | if (io->use_scaling) { |
| 759 | // disable filter (only for large downscaling ratio). |
| 760 | io->bypass_filtering = (io->scaled_width < W * 3 / 4) && |
| 761 | (io->scaled_height < H * 3 / 4); |
| 762 | io->fancy_upsampling = 0; |
| 763 | } |
| 764 | return 1; |
| 765 | } |
| 766 | |
| 767 | //------------------------------------------------------------------------------ |
| 768 | |
Eric Hassold | 9aea642 | 2011-01-04 17:22:46 -0800 | [diff] [blame] | 769 | #if defined(__cplusplus) || defined(c_plusplus) |
| 770 | } // extern "C" |
| 771 | #endif |