1 // Copyright 2015 The Chromium Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style license that can be 3 // found in the LICENSE file. 4 // 5 // This file contains an implementation of a VP9 bitstream parser. 6 // 7 // VERBOSE level: 8 // 1 something wrong in bitstream 9 // 2 parsing steps 10 // 3 parsed values (selected) 11 // Note: ported from Chromium commit head: 2de6929 12 13 #include "vp9_parser.h" 14 15 #include <algorithm> 16 17 #include "base/bind.h" 18 #include "base/logging.h" 19 #include "base/macros.h" 20 #include "base/numerics/safe_conversions.h" 21 #include "vp9_compressed_header_parser.h" 22 #include "vp9_uncompressed_header_parser.h" 23 24 namespace media { 25 26 namespace { 27 28 // Coefficients extracted verbatim from "VP9 Bitstream & Decoding Process 29 // Specification" Version 0.6, Sec 8.6.1 Dequantization functions, see: 30 // https://www.webmproject.org/vp9/#draft-vp9-bitstream-and-decoding-process-specification 31 constexpr size_t kQIndexRange = 256; 32 // clang-format off 33 // libva is the only user of high bit depth VP9 formats and only supports 34 // 10 bits per component, see https://github.com/01org/libva/issues/137. 35 // TODO(mcasas): Add the 12 bit versions of these tables. 36 const int16_t kDcQLookup[][kQIndexRange] = { 37 { 38 4, 8, 8, 9, 10, 11, 12, 12, 13, 14, 15, 16, 39 17, 18, 19, 19, 20, 21, 22, 23, 24, 25, 26, 26, 40 27, 28, 29, 30, 31, 32, 32, 33, 34, 35, 36, 37, 41 38, 38, 39, 40, 41, 42, 43, 43, 44, 45, 46, 47, 42 48, 48, 49, 50, 51, 52, 53, 53, 54, 55, 56, 57, 43 57, 58, 59, 60, 61, 62, 62, 63, 64, 65, 66, 66, 44 67, 68, 69, 70, 70, 71, 72, 73, 74, 74, 75, 76, 45 77, 78, 78, 79, 80, 81, 81, 82, 83, 84, 85, 85, 46 87, 88, 90, 92, 93, 95, 96, 98, 99, 101, 102, 104, 47 105, 107, 108, 110, 111, 113, 114, 116, 117, 118, 120, 121, 48 123, 125, 127, 129, 131, 134, 136, 138, 140, 142, 144, 146, 49 148, 150, 152, 154, 156, 158, 161, 164, 166, 169, 172, 174, 50 177, 180, 182, 185, 187, 190, 192, 195, 199, 202, 205, 208, 51 211, 214, 217, 220, 223, 226, 230, 233, 237, 240, 243, 247, 52 250, 253, 257, 261, 265, 269, 272, 276, 280, 284, 288, 292, 53 296, 300, 304, 309, 313, 317, 322, 326, 330, 335, 340, 344, 54 349, 354, 359, 364, 369, 374, 379, 384, 389, 395, 400, 406, 55 411, 417, 423, 429, 435, 441, 447, 454, 461, 467, 475, 482, 56 489, 497, 505, 513, 522, 530, 539, 549, 559, 569, 579, 590, 57 602, 614, 626, 640, 654, 668, 684, 700, 717, 736, 755, 775, 58 796, 819, 843, 869, 896, 925, 955, 988, 1022, 1058, 1098, 1139, 59 1184, 1232, 1282, 1336, 60 }, 61 { 62 4, 9, 10, 13, 15, 17, 20, 22, 25, 28, 31, 34, 63 37, 40, 43, 47, 50, 53, 57, 60, 64, 68, 71, 75, 64 78, 82, 86, 90, 93, 97, 101, 105, 109, 113, 116, 120, 65 124, 128, 132, 136, 140, 143, 147, 151, 155, 159, 163, 166, 66 170, 174, 178, 182, 185, 189, 193, 197, 200, 204, 208, 212, 67 215, 219, 223, 226, 230, 233, 237, 241, 244, 248, 251, 255, 68 259, 262, 266, 269, 273, 276, 280, 283, 287, 290, 293, 297, 69 300, 304, 307, 310, 314, 317, 321, 324, 327, 331, 334, 337, 70 343, 350, 356, 362, 369, 375, 381, 387, 394, 400, 406, 412, 71 418, 424, 430, 436, 442, 448, 454, 460, 466, 472, 478, 484, 72 490, 499, 507, 516, 525, 533, 542, 550, 559, 567, 576, 584, 73 592, 601, 609, 617, 625, 634, 644, 655, 666, 676, 687, 698, 74 708, 718, 729, 739, 749, 759, 770, 782, 795, 807, 819, 831, 75 844, 856, 868, 880, 891, 906, 920, 933, 947, 961, 975, 988, 76 1001, 1015, 1030, 1045, 1061, 1076, 1090, 1105, 1120, 1137, 1153, 1170, 77 1186, 1202, 1218, 1236, 1253, 1271, 1288, 1306, 1323, 1342, 1361, 1379, 78 1398, 1416, 1436, 1456, 1476, 1496, 1516, 1537, 1559, 1580, 1601, 1624, 79 1647, 1670, 1692, 1717, 1741, 1766, 1791, 1817, 1844, 1871, 1900, 1929, 80 1958, 1990, 2021, 2054, 2088, 2123, 2159, 2197, 2236, 2276, 2319, 2363, 81 2410, 2458, 2508, 2561, 2616, 2675, 2737, 2802, 2871, 2944, 3020, 3102, 82 3188, 3280, 3375, 3478, 3586, 3702, 3823, 3953, 4089, 4236, 4394, 4559, 83 4737, 4929, 5130, 5347 84 } 85 }; 86 87 const int16_t kAcQLookup[][kQIndexRange] = { 88 { 89 4, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 90 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 91 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 92 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 93 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 94 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 95 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 96 91, 92, 93, 94, 95, 96, 97, 98, 99, 100, 101, 102, 97 104, 106, 108, 110, 112, 114, 116, 118, 120, 122, 124, 126, 98 128, 130, 132, 134, 136, 138, 140, 142, 144, 146, 148, 150, 99 152, 155, 158, 161, 164, 167, 170, 173, 176, 179, 182, 185, 100 188, 191, 194, 197, 200, 203, 207, 211, 215, 219, 223, 227, 101 231, 235, 239, 243, 247, 251, 255, 260, 265, 270, 275, 280, 102 285, 290, 295, 300, 305, 311, 317, 323, 329, 335, 341, 347, 103 353, 359, 366, 373, 380, 387, 394, 401, 408, 416, 424, 432, 104 440, 448, 456, 465, 474, 483, 492, 501, 510, 520, 530, 540, 105 550, 560, 571, 582, 593, 604, 615, 627, 639, 651, 663, 676, 106 689, 702, 715, 729, 743, 757, 771, 786, 801, 816, 832, 848, 107 864, 881, 898, 915, 933, 951, 969, 988, 1007, 1026, 1046, 1066, 108 1087, 1108, 1129, 1151, 1173, 1196, 1219, 1243, 1267, 1292, 1317, 1343, 109 1369, 1396, 1423, 1451, 1479, 1508, 1537, 1567, 1597, 1628, 1660, 1692, 110 1725, 1759, 1793, 1828, 111 }, 112 { 113 4, 9, 11, 13, 16, 18, 21, 24, 27, 30, 33, 37, 114 40, 44, 48, 51, 55, 59, 63, 67, 71, 75, 79, 83, 115 88, 92, 96, 100, 105, 109, 114, 118, 122, 127, 131, 136, 116 140, 145, 149, 154, 158, 163, 168, 172, 177, 181, 186, 190, 117 195, 199, 204, 208, 213, 217, 222, 226, 231, 235, 240, 244, 118 249, 253, 258, 262, 267, 271, 275, 280, 284, 289, 293, 297, 119 302, 306, 311, 315, 319, 324, 328, 332, 337, 341, 345, 349, 120 354, 358, 362, 367, 371, 375, 379, 384, 388, 392, 396, 401, 121 409, 417, 425, 433, 441, 449, 458, 466, 474, 482, 490, 498, 122 506, 514, 523, 531, 539, 547, 555, 563, 571, 579, 588, 596, 123 604, 616, 628, 640, 652, 664, 676, 688, 700, 713, 725, 737, 124 749, 761, 773, 785, 797, 809, 825, 841, 857, 873, 889, 905, 125 922, 938, 954, 970, 986, 1002, 1018, 1038, 1058, 1078, 1098, 1118, 126 1138, 1158, 1178, 1198, 1218, 1242, 1266, 1290, 1314, 1338, 1362, 1386, 127 1411, 1435, 1463, 1491, 1519, 1547, 1575, 1603, 1631, 1663, 1695, 1727, 128 1759, 1791, 1823, 1859, 1895, 1931, 1967, 2003, 2039, 2079, 2119, 2159, 129 2199, 2239, 2283, 2327, 2371, 2415, 2459, 2507, 2555, 2603, 2651, 2703, 130 2755, 2807, 2859, 2915, 2971, 3027, 3083, 3143, 3203, 3263, 3327, 3391, 131 3455, 3523, 3591, 3659, 3731, 3803, 3876, 3952, 4028, 4104, 4184, 4264, 132 4348, 4432, 4516, 4604, 4692, 4784, 4876, 4972, 5068, 5168, 5268, 5372, 133 5476, 5584, 5692, 5804, 5916, 6032, 6148, 6268, 6388, 6512, 6640, 6768, 134 6900, 7036, 7172, 7312 135 } 136 }; 137 // clang-format on 138 139 static_assert(arraysize(kDcQLookup[0]) == arraysize(kAcQLookup[0]), 140 "quantizer lookup arrays of incorrect size"); 141 142 size_t ClampQ(size_t q) { 143 return std::min(q, kQIndexRange - 1); 144 } 145 146 int ClampLf(int lf) { 147 const int kMaxLoopFilterLevel = 63; 148 return std::min(std::max(0, lf), kMaxLoopFilterLevel); 149 } 150 151 } // namespace 152 153 bool Vp9FrameHeader::IsKeyframe() const { 154 // When show_existing_frame is true, the frame header does not precede an 155 // actual frame to be decoded, so frame_type does not apply (and is not read 156 // from the stream). 157 return !show_existing_frame && frame_type == KEYFRAME; 158 } 159 160 bool Vp9FrameHeader::IsIntra() const { 161 return !show_existing_frame && (frame_type == KEYFRAME || intra_only); 162 } 163 164 Vp9Parser::FrameInfo::FrameInfo(const uint8_t* ptr, off_t size) 165 : ptr(ptr), size(size) {} 166 167 bool Vp9FrameContext::IsValid() const { 168 // probs should be in [1, 255] range. 169 static_assert(sizeof(Vp9Prob) == 1, 170 "following checks assuming Vp9Prob is single byte"); 171 if (memchr(tx_probs_8x8, 0, sizeof(tx_probs_8x8))) 172 return false; 173 if (memchr(tx_probs_16x16, 0, sizeof(tx_probs_16x16))) 174 return false; 175 if (memchr(tx_probs_32x32, 0, sizeof(tx_probs_32x32))) 176 return false; 177 178 for (auto& a : coef_probs) { 179 for (auto& ai : a) { 180 for (auto& aj : ai) { 181 for (auto& ak : aj) { 182 int max_l = (ak == aj[0]) ? 3 : 6; 183 for (int l = 0; l < max_l; l++) { 184 for (auto& x : ak[l]) { 185 if (x == 0) 186 return false; 187 } 188 } 189 } 190 } 191 } 192 } 193 if (memchr(skip_prob, 0, sizeof(skip_prob))) 194 return false; 195 if (memchr(inter_mode_probs, 0, sizeof(inter_mode_probs))) 196 return false; 197 if (memchr(interp_filter_probs, 0, sizeof(interp_filter_probs))) 198 return false; 199 if (memchr(is_inter_prob, 0, sizeof(is_inter_prob))) 200 return false; 201 if (memchr(comp_mode_prob, 0, sizeof(comp_mode_prob))) 202 return false; 203 if (memchr(single_ref_prob, 0, sizeof(single_ref_prob))) 204 return false; 205 if (memchr(comp_ref_prob, 0, sizeof(comp_ref_prob))) 206 return false; 207 if (memchr(y_mode_probs, 0, sizeof(y_mode_probs))) 208 return false; 209 if (memchr(uv_mode_probs, 0, sizeof(uv_mode_probs))) 210 return false; 211 if (memchr(partition_probs, 0, sizeof(partition_probs))) 212 return false; 213 if (memchr(mv_joint_probs, 0, sizeof(mv_joint_probs))) 214 return false; 215 if (memchr(mv_sign_prob, 0, sizeof(mv_sign_prob))) 216 return false; 217 if (memchr(mv_class_probs, 0, sizeof(mv_class_probs))) 218 return false; 219 if (memchr(mv_class0_bit_prob, 0, sizeof(mv_class0_bit_prob))) 220 return false; 221 if (memchr(mv_bits_prob, 0, sizeof(mv_bits_prob))) 222 return false; 223 if (memchr(mv_class0_fr_probs, 0, sizeof(mv_class0_fr_probs))) 224 return false; 225 if (memchr(mv_fr_probs, 0, sizeof(mv_fr_probs))) 226 return false; 227 if (memchr(mv_class0_hp_prob, 0, sizeof(mv_class0_hp_prob))) 228 return false; 229 if (memchr(mv_hp_prob, 0, sizeof(mv_hp_prob))) 230 return false; 231 232 return true; 233 } 234 235 Vp9Parser::Context::Vp9FrameContextManager::Vp9FrameContextManager() 236 : weak_ptr_factory_(this) {} 237 238 Vp9Parser::Context::Vp9FrameContextManager::~Vp9FrameContextManager() = default; 239 240 const Vp9FrameContext& 241 Vp9Parser::Context::Vp9FrameContextManager::frame_context() const { 242 DCHECK(initialized_); 243 DCHECK(!needs_client_update_); 244 return frame_context_; 245 } 246 247 void Vp9Parser::Context::Vp9FrameContextManager::Reset() { 248 initialized_ = false; 249 needs_client_update_ = false; 250 weak_ptr_factory_.InvalidateWeakPtrs(); 251 } 252 253 void Vp9Parser::Context::Vp9FrameContextManager::SetNeedsClientUpdate() { 254 DCHECK(!needs_client_update_); 255 initialized_ = true; 256 needs_client_update_ = true; 257 } 258 259 Vp9Parser::ContextRefreshCallback 260 Vp9Parser::Context::Vp9FrameContextManager::GetUpdateCb() { 261 if (needs_client_update_) 262 return base::Bind(&Vp9FrameContextManager::UpdateFromClient, 263 weak_ptr_factory_.GetWeakPtr()); 264 else 265 return Vp9Parser::ContextRefreshCallback(); 266 } 267 268 void Vp9Parser::Context::Vp9FrameContextManager::Update( 269 const Vp9FrameContext& frame_context) { 270 // DCHECK because we can trust values from our parser. 271 DCHECK(frame_context.IsValid()); 272 initialized_ = true; 273 frame_context_ = frame_context; 274 275 // For frame context we are updating, it may be still awaiting previous 276 // ContextRefreshCallback. Because we overwrite the value of context here and 277 // previous ContextRefreshCallback no longer matters, invalidate the weak ptr 278 // to prevent previous ContextRefreshCallback run. 279 // With this optimization, we may be able to parse more frames while previous 280 // are still decoding. 281 weak_ptr_factory_.InvalidateWeakPtrs(); 282 needs_client_update_ = false; 283 } 284 285 void Vp9Parser::Context::Vp9FrameContextManager::UpdateFromClient( 286 const Vp9FrameContext& frame_context) { 287 DVLOG(2) << "Got external frame_context update"; 288 DCHECK(needs_client_update_); 289 if (!frame_context.IsValid()) { 290 DLOG(ERROR) << "Invalid prob value in frame_context"; 291 return; 292 } 293 needs_client_update_ = false; 294 initialized_ = true; 295 frame_context_ = frame_context; 296 } 297 298 void Vp9Parser::Context::Reset() { 299 memset(&segmentation_, 0, sizeof(segmentation_)); 300 memset(&loop_filter_, 0, sizeof(loop_filter_)); 301 memset(&ref_slots_, 0, sizeof(ref_slots_)); 302 for (auto& manager : frame_context_managers_) 303 manager.Reset(); 304 } 305 306 void Vp9Parser::Context::MarkFrameContextForUpdate(size_t frame_context_idx) { 307 DCHECK_LT(frame_context_idx, arraysize(frame_context_managers_)); 308 frame_context_managers_[frame_context_idx].SetNeedsClientUpdate(); 309 } 310 311 void Vp9Parser::Context::UpdateFrameContext( 312 size_t frame_context_idx, 313 const Vp9FrameContext& frame_context) { 314 DCHECK_LT(frame_context_idx, arraysize(frame_context_managers_)); 315 frame_context_managers_[frame_context_idx].Update(frame_context); 316 } 317 318 const Vp9Parser::ReferenceSlot& Vp9Parser::Context::GetRefSlot( 319 size_t ref_type) const { 320 DCHECK_LT(ref_type, arraysize(ref_slots_)); 321 return ref_slots_[ref_type]; 322 } 323 324 void Vp9Parser::Context::UpdateRefSlot( 325 size_t ref_type, 326 const Vp9Parser::ReferenceSlot& ref_slot) { 327 DCHECK_LT(ref_type, arraysize(ref_slots_)); 328 ref_slots_[ref_type] = ref_slot; 329 } 330 331 Vp9Parser::Vp9Parser(bool parsing_compressed_header) 332 : parsing_compressed_header_(parsing_compressed_header) { 333 Reset(); 334 } 335 336 Vp9Parser::~Vp9Parser() = default; 337 338 void Vp9Parser::SetStream(const uint8_t* stream, off_t stream_size) { 339 DCHECK(stream); 340 stream_ = stream; 341 bytes_left_ = stream_size; 342 frames_.clear(); 343 } 344 345 void Vp9Parser::Reset() { 346 stream_ = nullptr; 347 bytes_left_ = 0; 348 frames_.clear(); 349 curr_frame_info_.Reset(); 350 351 context_.Reset(); 352 } 353 354 bool Vp9Parser::ParseUncompressedHeader(const FrameInfo& frame_info, 355 Vp9FrameHeader* fhdr, 356 Result* result) { 357 memset(&curr_frame_header_, 0, sizeof(curr_frame_header_)); 358 *result = kInvalidStream; 359 360 Vp9UncompressedHeaderParser uncompressed_parser(&context_); 361 if (!uncompressed_parser.Parse(frame_info.ptr, frame_info.size, 362 &curr_frame_header_)) { 363 *result = kInvalidStream; 364 return true; 365 } 366 367 if (curr_frame_header_.header_size_in_bytes == 0) { 368 // Verify padding bits are zero. 369 for (off_t i = curr_frame_header_.uncompressed_header_size; 370 i < frame_info.size; i++) { 371 if (frame_info.ptr[i] != 0) { 372 DVLOG(1) << "Padding bits are not zeros."; 373 *result = kInvalidStream; 374 return true; 375 } 376 } 377 *fhdr = curr_frame_header_; 378 *result = kOk; 379 return true; 380 } 381 if (curr_frame_header_.uncompressed_header_size + 382 curr_frame_header_.header_size_in_bytes > 383 base::checked_cast<size_t>(frame_info.size)) { 384 DVLOG(1) << "header_size_in_bytes=" 385 << curr_frame_header_.header_size_in_bytes 386 << " is larger than bytes left in buffer: " 387 << frame_info.size - curr_frame_header_.uncompressed_header_size; 388 *result = kInvalidStream; 389 return true; 390 } 391 392 return false; 393 } 394 395 bool Vp9Parser::ParseCompressedHeader(const FrameInfo& frame_info, 396 Result* result) { 397 *result = kInvalidStream; 398 size_t frame_context_idx = curr_frame_header_.frame_context_idx; 399 const Context::Vp9FrameContextManager& context_to_load = 400 context_.frame_context_managers_[frame_context_idx]; 401 if (!context_to_load.initialized()) { 402 // 8.2 Frame order constraints 403 // must load an initialized set of probabilities. 404 DVLOG(1) << "loading uninitialized frame context, index=" 405 << frame_context_idx; 406 *result = kInvalidStream; 407 return true; 408 } 409 if (context_to_load.needs_client_update()) { 410 DVLOG(3) << "waiting frame_context_idx=" << frame_context_idx 411 << " to update"; 412 curr_frame_info_ = frame_info; 413 *result = kAwaitingRefresh; 414 return true; 415 } 416 curr_frame_header_.initial_frame_context = curr_frame_header_.frame_context = 417 context_to_load.frame_context(); 418 419 Vp9CompressedHeaderParser compressed_parser; 420 if (!compressed_parser.Parse( 421 frame_info.ptr + curr_frame_header_.uncompressed_header_size, 422 curr_frame_header_.header_size_in_bytes, &curr_frame_header_)) { 423 *result = kInvalidStream; 424 return true; 425 } 426 427 if (curr_frame_header_.refresh_frame_context) { 428 // In frame parallel mode, we can refresh the context without decoding 429 // tile data. 430 if (curr_frame_header_.frame_parallel_decoding_mode) { 431 context_.UpdateFrameContext(frame_context_idx, 432 curr_frame_header_.frame_context); 433 } else { 434 context_.MarkFrameContextForUpdate(frame_context_idx); 435 } 436 } 437 return false; 438 } 439 440 Vp9Parser::Result Vp9Parser::ParseNextFrame(Vp9FrameHeader* fhdr) { 441 DCHECK(fhdr); 442 DVLOG(2) << "ParseNextFrame"; 443 FrameInfo frame_info; 444 Result result; 445 446 // If |curr_frame_info_| is valid, uncompressed header was parsed into 447 // |curr_frame_header_| and we are awaiting context update to proceed with 448 // compressed header parsing. 449 if (curr_frame_info_.IsValid()) { 450 DCHECK(parsing_compressed_header_); 451 frame_info = curr_frame_info_; 452 curr_frame_info_.Reset(); 453 } else { 454 if (frames_.empty()) { 455 // No frames to be decoded, if there is no more stream, request more. 456 if (!stream_) 457 return kEOStream; 458 459 // New stream to be parsed, parse it and fill frames_. 460 frames_ = ParseSuperframe(); 461 if (frames_.empty()) { 462 DVLOG(1) << "Failed parsing superframes"; 463 return kInvalidStream; 464 } 465 } 466 467 frame_info = frames_.front(); 468 frames_.pop_front(); 469 470 if (ParseUncompressedHeader(frame_info, fhdr, &result)) 471 return result; 472 } 473 474 if (parsing_compressed_header_) { 475 if (ParseCompressedHeader(frame_info, &result)) { 476 DCHECK(result != kAwaitingRefresh || curr_frame_info_.IsValid()); 477 return result; 478 } 479 } 480 481 if (!SetupSegmentationDequant()) 482 return kInvalidStream; 483 SetupLoopFilter(); 484 UpdateSlots(); 485 486 *fhdr = curr_frame_header_; 487 return kOk; 488 } 489 490 Vp9Parser::ContextRefreshCallback Vp9Parser::GetContextRefreshCb( 491 size_t frame_context_idx) { 492 DCHECK_LT(frame_context_idx, arraysize(context_.frame_context_managers_)); 493 auto& frame_context_manager = 494 context_.frame_context_managers_[frame_context_idx]; 495 496 return frame_context_manager.GetUpdateCb(); 497 } 498 499 // Annex B Superframes 500 std::deque<Vp9Parser::FrameInfo> Vp9Parser::ParseSuperframe() { 501 const uint8_t* stream = stream_; 502 off_t bytes_left = bytes_left_; 503 504 // Make sure we don't parse stream_ more than once. 505 stream_ = nullptr; 506 bytes_left_ = 0; 507 508 if (bytes_left < 1) 509 return std::deque<FrameInfo>(); 510 511 // If this is a superframe, the last byte in the stream will contain the 512 // superframe marker. If not, the whole buffer contains a single frame. 513 uint8_t marker = *(stream + bytes_left - 1); 514 if ((marker & 0xe0) != 0xc0) { 515 return {FrameInfo(stream, bytes_left)}; 516 } 517 518 DVLOG(1) << "Parsing a superframe"; 519 520 // The bytes immediately before the superframe marker constitute superframe 521 // index, which stores information about sizes of each frame in it. 522 // Calculate its size and set index_ptr to the beginning of it. 523 size_t num_frames = (marker & 0x7) + 1; 524 size_t mag = ((marker >> 3) & 0x3) + 1; 525 off_t index_size = 2 + mag * num_frames; 526 527 if (bytes_left < index_size) 528 return std::deque<FrameInfo>(); 529 530 const uint8_t* index_ptr = stream + bytes_left - index_size; 531 if (marker != *index_ptr) 532 return std::deque<FrameInfo>(); 533 534 ++index_ptr; 535 bytes_left -= index_size; 536 537 // Parse frame information contained in the index and add a pointer to and 538 // size of each frame to frames. 539 std::deque<FrameInfo> frames; 540 for (size_t i = 0; i < num_frames; ++i) { 541 uint32_t size = 0; 542 for (size_t j = 0; j < mag; ++j) { 543 size |= *index_ptr << (j * 8); 544 ++index_ptr; 545 } 546 547 if (base::checked_cast<off_t>(size) > bytes_left) { 548 DVLOG(1) << "Not enough data in the buffer for frame " << i; 549 return std::deque<FrameInfo>(); 550 } 551 552 frames.push_back(FrameInfo(stream, size)); 553 stream += size; 554 bytes_left -= size; 555 556 DVLOG(1) << "Frame " << i << ", size: " << size; 557 } 558 559 return frames; 560 } 561 562 // 8.6.1 Dequantization functions 563 size_t Vp9Parser::GetQIndex(const Vp9QuantizationParams& quant, 564 size_t segid) const { 565 const Vp9SegmentationParams& segmentation = context_.segmentation(); 566 567 if (segmentation.FeatureEnabled(segid, 568 Vp9SegmentationParams::SEG_LVL_ALT_Q)) { 569 int16_t feature_data = 570 segmentation.FeatureData(segid, Vp9SegmentationParams::SEG_LVL_ALT_Q); 571 size_t q_index = segmentation.abs_or_delta_update 572 ? feature_data 573 : quant.base_q_idx + feature_data; 574 return ClampQ(q_index); 575 } 576 577 return quant.base_q_idx; 578 } 579 580 // 8.6.1 Dequantization functions 581 bool Vp9Parser::SetupSegmentationDequant() { 582 const Vp9QuantizationParams& quant = curr_frame_header_.quant_params; 583 Vp9SegmentationParams& segmentation = context_.segmentation_; 584 585 if (curr_frame_header_.bit_depth > 10) { 586 DLOG(ERROR) << "bit_depth > 10 is not supported yet, kDcQLookup and " 587 "kAcQLookup need to be extended"; 588 return false; 589 } 590 const size_t bit_depth_index = (curr_frame_header_.bit_depth == 8) ? 0 : 1; 591 592 if (segmentation.enabled) { 593 for (size_t i = 0; i < Vp9SegmentationParams::kNumSegments; ++i) { 594 const size_t q_index = GetQIndex(quant, i); 595 segmentation.y_dequant[i][0] = 596 kDcQLookup[bit_depth_index][ClampQ(q_index + quant.delta_q_y_dc)]; 597 segmentation.y_dequant[i][1] = 598 kAcQLookup[bit_depth_index][ClampQ(q_index)]; 599 segmentation.uv_dequant[i][0] = 600 kDcQLookup[bit_depth_index][ClampQ(q_index + quant.delta_q_uv_dc)]; 601 segmentation.uv_dequant[i][1] = 602 kAcQLookup[bit_depth_index][ClampQ(q_index + quant.delta_q_uv_ac)]; 603 } 604 } else { 605 const size_t q_index = quant.base_q_idx; 606 segmentation.y_dequant[0][0] = 607 kDcQLookup[bit_depth_index][ClampQ(q_index + quant.delta_q_y_dc)]; 608 segmentation.y_dequant[0][1] = kAcQLookup[bit_depth_index][ClampQ(q_index)]; 609 segmentation.uv_dequant[0][0] = 610 kDcQLookup[bit_depth_index][ClampQ(q_index + quant.delta_q_uv_dc)]; 611 segmentation.uv_dequant[0][1] = 612 kAcQLookup[bit_depth_index][ClampQ(q_index + quant.delta_q_uv_ac)]; 613 } 614 return true; 615 } 616 617 // 8.8.1 Loop filter frame init process 618 void Vp9Parser::SetupLoopFilter() { 619 Vp9LoopFilterParams& loop_filter = context_.loop_filter_; 620 if (!loop_filter.level) 621 return; 622 623 int scale = loop_filter.level < 32 ? 1 : 2; 624 625 for (size_t i = 0; i < Vp9SegmentationParams::kNumSegments; ++i) { 626 int level = loop_filter.level; 627 const Vp9SegmentationParams& segmentation = context_.segmentation(); 628 629 if (segmentation.FeatureEnabled(i, Vp9SegmentationParams::SEG_LVL_ALT_LF)) { 630 int feature_data = 631 segmentation.FeatureData(i, Vp9SegmentationParams::SEG_LVL_ALT_LF); 632 level = ClampLf(segmentation.abs_or_delta_update ? feature_data 633 : level + feature_data); 634 } 635 636 if (!loop_filter.delta_enabled) { 637 memset(loop_filter.lvl[i], level, sizeof(loop_filter.lvl[i])); 638 } else { 639 loop_filter.lvl[i][Vp9RefType::VP9_FRAME_INTRA][0] = ClampLf( 640 level + loop_filter.ref_deltas[Vp9RefType::VP9_FRAME_INTRA] * scale); 641 loop_filter.lvl[i][Vp9RefType::VP9_FRAME_INTRA][1] = 0; 642 643 for (size_t type = Vp9RefType::VP9_FRAME_LAST; 644 type < Vp9RefType::VP9_FRAME_MAX; ++type) { 645 for (size_t mode = 0; mode < Vp9LoopFilterParams::kNumModeDeltas; 646 ++mode) { 647 loop_filter.lvl[i][type][mode] = 648 ClampLf(level + loop_filter.ref_deltas[type] * scale + 649 loop_filter.mode_deltas[mode] * scale); 650 } 651 } 652 } 653 } 654 } 655 656 void Vp9Parser::UpdateSlots() { 657 // 8.10 Reference frame update process 658 for (size_t i = 0; i < kVp9NumRefFrames; i++) { 659 if (curr_frame_header_.RefreshFlag(i)) { 660 ReferenceSlot ref_slot; 661 ref_slot.initialized = true; 662 663 ref_slot.frame_width = curr_frame_header_.frame_width; 664 ref_slot.frame_height = curr_frame_header_.frame_height; 665 ref_slot.subsampling_x = curr_frame_header_.subsampling_x; 666 ref_slot.subsampling_y = curr_frame_header_.subsampling_y; 667 ref_slot.bit_depth = curr_frame_header_.bit_depth; 668 669 ref_slot.profile = curr_frame_header_.profile; 670 ref_slot.color_space = curr_frame_header_.color_space; 671 context_.UpdateRefSlot(i, ref_slot); 672 } 673 } 674 } 675 676 } // namespace media 677
