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| 1 /* | |
| 2 * Copyright (c) 2015 The WebRTC project authors. All Rights Reserved. | |
| 3 * | |
| 4 * Use of this source code is governed by a BSD-style license | |
| 5 * that can be found in the LICENSE file in the root of the source | |
| 6 * tree. An additional intellectual property rights grant can be found | |
| 7 * in the file PATENTS. All contributing project authors may | |
| 8 * be found in the AUTHORS file in the root of the source tree. | |
| 9 */ | |
| 10 #include "webrtc/modules/rtp_rtcp/source/h264_bitstream_parser.h" | |
| 11 | |
| 12 #include <memory> | |
| 13 #include <vector> | |
| 14 | |
| 15 #include "webrtc/base/bitbuffer.h" | |
| 16 #include "webrtc/base/bytebuffer.h" | |
| 17 #include "webrtc/base/checks.h" | |
| 18 #include "webrtc/base/logging.h" | |
| 19 | |
| 20 namespace webrtc { | |
| 21 namespace { | |
| 22 // The size of a NALU header {0 0 0 1}. | |
| 23 static const size_t kNaluHeaderSize = 4; | |
| 24 | |
| 25 // The size of a NALU header plus the type byte. | |
| 26 static const size_t kNaluHeaderAndTypeSize = kNaluHeaderSize + 1; | |
| 27 | |
| 28 // The NALU type. | |
| 29 static const uint8_t kNaluSps = 0x7; | |
| 30 static const uint8_t kNaluPps = 0x8; | |
| 31 static const uint8_t kNaluIdr = 0x5; | |
| 32 static const uint8_t kNaluTypeMask = 0x1F; | |
| 33 | |
| 34 static const uint8_t kSliceTypeP = 0x0; | |
| 35 static const uint8_t kSliceTypeB = 0x1; | |
| 36 static const uint8_t kSliceTypeSp = 0x3; | |
| 37 | |
| 38 // Returns a vector of the NALU start sequences (0 0 0 1) in the given buffer. | |
| 39 std::vector<size_t> FindNaluStartSequences(const uint8_t* buffer, | |
| 40 size_t buffer_size) { | |
| 41 std::vector<size_t> sequences; | |
| 42 // This is sorta like Boyer-Moore, but with only the first optimization step: | |
| 43 // given a 4-byte sequence we're looking at, if the 4th byte isn't 1 or 0, | |
| 44 // skip ahead to the next 4-byte sequence. 0s and 1s are relatively rare, so | |
| 45 // this will skip the majority of reads/checks. | |
| 46 const uint8_t* end = buffer + buffer_size - 4; | |
| 47 for (const uint8_t* head = buffer; head < end;) { | |
| 48 if (head[3] > 1) { | |
| 49 head += 4; | |
| 50 } else if (head[3] == 1 && head[2] == 0 && head[1] == 0 && head[0] == 0) { | |
| 51 sequences.push_back(static_cast<size_t>(head - buffer)); | |
| 52 head += 4; | |
| 53 } else { | |
| 54 head++; | |
| 55 } | |
| 56 } | |
| 57 | |
| 58 return sequences; | |
| 59 } | |
| 60 } // namespace | |
| 61 | |
| 62 // Parses RBSP from source bytes. Removes emulation bytes, but leaves the | |
| 63 // rbsp_trailing_bits() in the stream, since none of the parsing reads all the | |
| 64 // way to the end of a parsed RBSP sequence. When writing, that means the | |
| 65 // rbsp_trailing_bits() should be preserved and don't need to be restored (i.e. | |
| 66 // the rbsp_stop_one_bit, which is just a 1, then zero padded), and alignment | |
| 67 // should "just work". | |
| 68 // TODO(pbos): Make parsing RBSP something that can be integrated into BitBuffer | |
| 69 // so we don't have to copy the entire frames when only interested in the | |
| 70 // headers. | |
| 71 rtc::ByteBufferWriter* ParseRbsp(const uint8_t* bytes, size_t length) { | |
| 72 // Copied from webrtc::H264SpsParser::Parse. | |
| 73 rtc::ByteBufferWriter* rbsp_buffer = new rtc::ByteBufferWriter(); | |
| 74 for (size_t i = 0; i < length;) { | |
| 75 if (length - i >= 3 && bytes[i] == 0 && bytes[i + 1] == 0 && | |
| 76 bytes[i + 2] == 3) { | |
| 77 rbsp_buffer->WriteBytes(reinterpret_cast<const char*>(bytes) + i, 2); | |
| 78 i += 3; | |
| 79 } else { | |
| 80 rbsp_buffer->WriteBytes(reinterpret_cast<const char*>(bytes) + i, 1); | |
| 81 i++; | |
| 82 } | |
| 83 } | |
| 84 return rbsp_buffer; | |
| 85 } | |
| 86 | |
| 87 #define RETURN_FALSE_ON_FAIL(x) \ | |
| 88 if (!(x)) { \ | |
| 89 LOG_F(LS_ERROR) << "FAILED: " #x; \ | |
| 90 return false; \ | |
| 91 } | |
| 92 | |
| 93 H264BitstreamParser::PpsState::PpsState() {} | |
| 94 | |
| 95 H264BitstreamParser::SpsState::SpsState() {} | |
| 96 | |
| 97 // These functions are similar to webrtc::H264SpsParser::Parse, and based on the | |
| 98 // same version of the H.264 standard. You can find it here: | |
| 99 // http://www.itu.int/rec/T-REC-H.264 | |
| 100 bool H264BitstreamParser::ParseSpsNalu(const uint8_t* sps, size_t length) { | |
| 101 // Reset SPS state. | |
| 102 sps_ = SpsState(); | |
| 103 sps_parsed_ = false; | |
| 104 // Parse out the SPS RBSP. It should be small, so it's ok that we create a | |
| 105 // copy. We'll eventually write this back. | |
| 106 std::unique_ptr<rtc::ByteBufferWriter> sps_rbsp( | |
| 107 ParseRbsp(sps + kNaluHeaderAndTypeSize, length - kNaluHeaderAndTypeSize)); | |
| 108 rtc::BitBuffer sps_parser(reinterpret_cast<const uint8_t*>(sps_rbsp->Data()), | |
| 109 sps_rbsp->Length()); | |
| 110 | |
| 111 uint8_t byte_tmp; | |
| 112 uint32_t golomb_tmp; | |
| 113 uint32_t bits_tmp; | |
| 114 | |
| 115 // profile_idc: u(8). | |
| 116 uint8_t profile_idc; | |
| 117 RETURN_FALSE_ON_FAIL(sps_parser.ReadUInt8(&profile_idc)); | |
| 118 // constraint_set0_flag through constraint_set5_flag + reserved_zero_2bits | |
| 119 // 1 bit each for the flags + 2 bits = 8 bits = 1 byte. | |
| 120 RETURN_FALSE_ON_FAIL(sps_parser.ReadUInt8(&byte_tmp)); | |
| 121 // level_idc: u(8) | |
| 122 RETURN_FALSE_ON_FAIL(sps_parser.ReadUInt8(&byte_tmp)); | |
| 123 // seq_parameter_set_id: ue(v) | |
| 124 RETURN_FALSE_ON_FAIL(sps_parser.ReadExponentialGolomb(&golomb_tmp)); | |
| 125 sps_.separate_colour_plane_flag = 0; | |
| 126 // See if profile_idc has chroma format information. | |
| 127 if (profile_idc == 100 || profile_idc == 110 || profile_idc == 122 || | |
| 128 profile_idc == 244 || profile_idc == 44 || profile_idc == 83 || | |
| 129 profile_idc == 86 || profile_idc == 118 || profile_idc == 128 || | |
| 130 profile_idc == 138 || profile_idc == 139 || profile_idc == 134) { | |
| 131 // chroma_format_idc: ue(v) | |
| 132 uint32_t chroma_format_idc; | |
| 133 RETURN_FALSE_ON_FAIL(sps_parser.ReadExponentialGolomb(&chroma_format_idc)); | |
| 134 if (chroma_format_idc == 3) { | |
| 135 // separate_colour_plane_flag: u(1) | |
| 136 RETURN_FALSE_ON_FAIL( | |
| 137 sps_parser.ReadBits(&sps_.separate_colour_plane_flag, 1)); | |
| 138 } | |
| 139 // bit_depth_luma_minus8: ue(v) | |
| 140 RETURN_FALSE_ON_FAIL(sps_parser.ReadExponentialGolomb(&golomb_tmp)); | |
| 141 // bit_depth_chroma_minus8: ue(v) | |
| 142 RETURN_FALSE_ON_FAIL(sps_parser.ReadExponentialGolomb(&golomb_tmp)); | |
| 143 // qpprime_y_zero_transform_bypass_flag: u(1) | |
| 144 RETURN_FALSE_ON_FAIL(sps_parser.ReadBits(&bits_tmp, 1)); | |
| 145 // seq_scaling_matrix_present_flag: u(1) | |
| 146 uint32_t seq_scaling_matrix_present_flag; | |
| 147 RETURN_FALSE_ON_FAIL( | |
| 148 sps_parser.ReadBits(&seq_scaling_matrix_present_flag, 1)); | |
| 149 if (seq_scaling_matrix_present_flag) { | |
| 150 // seq_scaling_list_present_flags. Either 8 or 12, depending on | |
| 151 // chroma_format_idc. | |
| 152 uint32_t seq_scaling_list_present_flags; | |
| 153 if (chroma_format_idc != 3) { | |
| 154 RETURN_FALSE_ON_FAIL( | |
| 155 sps_parser.ReadBits(&seq_scaling_list_present_flags, 8)); | |
| 156 } else { | |
| 157 RETURN_FALSE_ON_FAIL( | |
| 158 sps_parser.ReadBits(&seq_scaling_list_present_flags, 12)); | |
| 159 } | |
| 160 // TODO(pbos): Support parsing scaling lists if they're seen in practice. | |
| 161 RTC_CHECK(seq_scaling_list_present_flags == 0) | |
| 162 << "SPS contains scaling lists, which are unsupported."; | |
| 163 } | |
| 164 } | |
| 165 // log2_max_frame_num_minus4: ue(v) | |
| 166 RETURN_FALSE_ON_FAIL( | |
| 167 sps_parser.ReadExponentialGolomb(&sps_.log2_max_frame_num_minus4)); | |
| 168 // pic_order_cnt_type: ue(v) | |
| 169 RETURN_FALSE_ON_FAIL( | |
| 170 sps_parser.ReadExponentialGolomb(&sps_.pic_order_cnt_type)); | |
| 171 | |
| 172 if (sps_.pic_order_cnt_type == 0) { | |
| 173 // log2_max_pic_order_cnt_lsb_minus4: ue(v) | |
| 174 RETURN_FALSE_ON_FAIL(sps_parser.ReadExponentialGolomb( | |
| 175 &sps_.log2_max_pic_order_cnt_lsb_minus4)); | |
| 176 } else if (sps_.pic_order_cnt_type == 1) { | |
| 177 // delta_pic_order_always_zero_flag: u(1) | |
| 178 RETURN_FALSE_ON_FAIL( | |
| 179 sps_parser.ReadBits(&sps_.delta_pic_order_always_zero_flag, 1)); | |
| 180 // offset_for_non_ref_pic: se(v) | |
| 181 RETURN_FALSE_ON_FAIL(sps_parser.ReadExponentialGolomb(&golomb_tmp)); | |
| 182 // offset_for_top_to_bottom_field: se(v) | |
| 183 RETURN_FALSE_ON_FAIL(sps_parser.ReadExponentialGolomb(&golomb_tmp)); | |
| 184 uint32_t num_ref_frames_in_pic_order_cnt_cycle; | |
| 185 // num_ref_frames_in_pic_order_cnt_cycle: ue(v) | |
| 186 RETURN_FALSE_ON_FAIL(sps_parser.ReadExponentialGolomb( | |
| 187 &num_ref_frames_in_pic_order_cnt_cycle)); | |
| 188 for (uint32_t i = 0; i < num_ref_frames_in_pic_order_cnt_cycle; i++) { | |
| 189 // offset_for_ref_frame[i]: se(v) | |
| 190 RETURN_FALSE_ON_FAIL(sps_parser.ReadExponentialGolomb(&golomb_tmp)); | |
| 191 } | |
| 192 } | |
| 193 // max_num_ref_frames: ue(v) | |
| 194 RETURN_FALSE_ON_FAIL(sps_parser.ReadExponentialGolomb(&golomb_tmp)); | |
| 195 // gaps_in_frame_num_value_allowed_flag: u(1) | |
| 196 RETURN_FALSE_ON_FAIL(sps_parser.ReadBits(&bits_tmp, 1)); | |
| 197 // pic_width_in_mbs_minus1: ue(v) | |
| 198 RETURN_FALSE_ON_FAIL(sps_parser.ReadExponentialGolomb(&golomb_tmp)); | |
| 199 // pic_height_in_map_units_minus1: ue(v) | |
| 200 RETURN_FALSE_ON_FAIL(sps_parser.ReadExponentialGolomb(&golomb_tmp)); | |
| 201 // frame_mbs_only_flag: u(1) | |
| 202 RETURN_FALSE_ON_FAIL(sps_parser.ReadBits(&sps_.frame_mbs_only_flag, 1)); | |
| 203 sps_parsed_ = true; | |
| 204 return true; | |
| 205 } | |
| 206 | |
| 207 bool H264BitstreamParser::ParsePpsNalu(const uint8_t* pps, size_t length) { | |
| 208 RTC_CHECK(sps_parsed_); | |
| 209 // We're starting a new stream, so reset picture type rewriting values. | |
| 210 pps_ = PpsState(); | |
| 211 pps_parsed_ = false; | |
| 212 std::unique_ptr<rtc::ByteBufferWriter> buffer( | |
| 213 ParseRbsp(pps + kNaluHeaderAndTypeSize, length - kNaluHeaderAndTypeSize)); | |
| 214 rtc::BitBuffer parser(reinterpret_cast<const uint8_t*>(buffer->Data()), | |
| 215 buffer->Length()); | |
| 216 | |
| 217 uint32_t bits_tmp; | |
| 218 uint32_t golomb_ignored; | |
| 219 // pic_parameter_set_id: ue(v) | |
| 220 RETURN_FALSE_ON_FAIL(parser.ReadExponentialGolomb(&golomb_ignored)); | |
| 221 // seq_parameter_set_id: ue(v) | |
| 222 RETURN_FALSE_ON_FAIL(parser.ReadExponentialGolomb(&golomb_ignored)); | |
| 223 // entropy_coding_mode_flag: u(1) | |
| 224 uint32_t entropy_coding_mode_flag; | |
| 225 RETURN_FALSE_ON_FAIL(parser.ReadBits(&entropy_coding_mode_flag, 1)); | |
| 226 // TODO(pbos): Implement CABAC support if spotted in the wild. | |
| 227 RTC_CHECK(entropy_coding_mode_flag == 0) | |
| 228 << "Don't know how to parse CABAC streams."; | |
| 229 // bottom_field_pic_order_in_frame_present_flag: u(1) | |
| 230 uint32_t bottom_field_pic_order_in_frame_present_flag; | |
| 231 RETURN_FALSE_ON_FAIL( | |
| 232 parser.ReadBits(&bottom_field_pic_order_in_frame_present_flag, 1)); | |
| 233 pps_.bottom_field_pic_order_in_frame_present_flag = | |
| 234 bottom_field_pic_order_in_frame_present_flag != 0; | |
| 235 | |
| 236 // num_slice_groups_minus1: ue(v) | |
| 237 uint32_t num_slice_groups_minus1; | |
| 238 RETURN_FALSE_ON_FAIL(parser.ReadExponentialGolomb(&num_slice_groups_minus1)); | |
| 239 if (num_slice_groups_minus1 > 0) { | |
| 240 uint32_t slice_group_map_type; | |
| 241 // slice_group_map_type: ue(v) | |
| 242 RETURN_FALSE_ON_FAIL(parser.ReadExponentialGolomb(&slice_group_map_type)); | |
| 243 if (slice_group_map_type == 0) { | |
| 244 for (uint32_t i_group = 0; i_group <= num_slice_groups_minus1; | |
| 245 ++i_group) { | |
| 246 // run_length_minus1[iGroup]: ue(v) | |
| 247 RETURN_FALSE_ON_FAIL(parser.ReadExponentialGolomb(&golomb_ignored)); | |
| 248 } | |
| 249 } else if (slice_group_map_type == 2) { | |
| 250 for (uint32_t i_group = 0; i_group <= num_slice_groups_minus1; | |
| 251 ++i_group) { | |
| 252 // top_left[iGroup]: ue(v) | |
| 253 RETURN_FALSE_ON_FAIL(parser.ReadExponentialGolomb(&golomb_ignored)); | |
| 254 // bottom_right[iGroup]: ue(v) | |
| 255 RETURN_FALSE_ON_FAIL(parser.ReadExponentialGolomb(&golomb_ignored)); | |
| 256 } | |
| 257 } else if (slice_group_map_type == 3 || slice_group_map_type == 4 || | |
| 258 slice_group_map_type == 5) { | |
| 259 // slice_group_change_direction_flag: u(1) | |
| 260 RETURN_FALSE_ON_FAIL(parser.ReadBits(&bits_tmp, 1)); | |
| 261 // slice_group_change_rate_minus1: ue(v) | |
| 262 RETURN_FALSE_ON_FAIL(parser.ReadExponentialGolomb(&golomb_ignored)); | |
| 263 } else if (slice_group_map_type == 6) { | |
| 264 // pic_size_in_map_units_minus1: ue(v) | |
| 265 uint32_t pic_size_in_map_units_minus1; | |
| 266 RETURN_FALSE_ON_FAIL( | |
| 267 parser.ReadExponentialGolomb(&pic_size_in_map_units_minus1)); | |
| 268 uint32_t slice_group_id_bits = 0; | |
| 269 uint32_t num_slice_groups = num_slice_groups_minus1 + 1; | |
| 270 // If num_slice_groups is not a power of two an additional bit is required | |
| 271 // to account for the ceil() of log2() below. | |
| 272 if ((num_slice_groups & (num_slice_groups - 1)) != 0) | |
| 273 ++slice_group_id_bits; | |
| 274 while (num_slice_groups > 0) { | |
| 275 num_slice_groups >>= 1; | |
| 276 ++slice_group_id_bits; | |
| 277 } | |
| 278 for (uint32_t i = 0; i <= pic_size_in_map_units_minus1; i++) { | |
| 279 // slice_group_id[i]: u(v) | |
| 280 // Represented by ceil(log2(num_slice_groups_minus1 + 1)) bits. | |
| 281 RETURN_FALSE_ON_FAIL(parser.ReadBits(&bits_tmp, slice_group_id_bits)); | |
| 282 } | |
| 283 } | |
| 284 } | |
| 285 // num_ref_idx_l0_default_active_minus1: ue(v) | |
| 286 RETURN_FALSE_ON_FAIL(parser.ReadExponentialGolomb(&golomb_ignored)); | |
| 287 // num_ref_idx_l1_default_active_minus1: ue(v) | |
| 288 RETURN_FALSE_ON_FAIL(parser.ReadExponentialGolomb(&golomb_ignored)); | |
| 289 // weighted_pred_flag: u(1) | |
| 290 uint32_t weighted_pred_flag; | |
| 291 RETURN_FALSE_ON_FAIL(parser.ReadBits(&weighted_pred_flag, 1)); | |
| 292 pps_.weighted_pred_flag = weighted_pred_flag != 0; | |
| 293 // weighted_bipred_idc: u(2) | |
| 294 RETURN_FALSE_ON_FAIL(parser.ReadBits(&pps_.weighted_bipred_idc, 2)); | |
| 295 | |
| 296 // pic_init_qp_minus26: se(v) | |
| 297 RETURN_FALSE_ON_FAIL( | |
| 298 parser.ReadSignedExponentialGolomb(&pps_.pic_init_qp_minus26)); | |
| 299 // pic_init_qs_minus26: se(v) | |
| 300 RETURN_FALSE_ON_FAIL(parser.ReadExponentialGolomb(&golomb_ignored)); | |
| 301 // chroma_qp_index_offset: se(v) | |
| 302 RETURN_FALSE_ON_FAIL(parser.ReadExponentialGolomb(&golomb_ignored)); | |
| 303 // deblocking_filter_control_present_flag: u(1) | |
| 304 // constrained_intra_pred_flag: u(1) | |
| 305 RETURN_FALSE_ON_FAIL(parser.ReadBits(&bits_tmp, 2)); | |
| 306 // redundant_pic_cnt_present_flag: u(1) | |
| 307 RETURN_FALSE_ON_FAIL( | |
| 308 parser.ReadBits(&pps_.redundant_pic_cnt_present_flag, 1)); | |
| 309 | |
| 310 pps_parsed_ = true; | |
| 311 return true; | |
| 312 } | |
| 313 | |
| 314 bool H264BitstreamParser::ParseNonParameterSetNalu(const uint8_t* source, | |
| 315 size_t source_length, | |
| 316 uint8_t nalu_type) { | |
| 317 RTC_CHECK(sps_parsed_); | |
| 318 RTC_CHECK(pps_parsed_); | |
| 319 last_slice_qp_delta_parsed_ = false; | |
| 320 std::unique_ptr<rtc::ByteBufferWriter> slice_rbsp(ParseRbsp( | |
| 321 source + kNaluHeaderAndTypeSize, source_length - kNaluHeaderAndTypeSize)); | |
| 322 rtc::BitBuffer slice_reader( | |
| 323 reinterpret_cast<const uint8_t*>(slice_rbsp->Data()), | |
| 324 slice_rbsp->Length()); | |
| 325 // Check to see if this is an IDR slice, which has an extra field to parse | |
| 326 // out. | |
| 327 bool is_idr = (source[kNaluHeaderSize] & 0x0F) == kNaluIdr; | |
| 328 uint8_t nal_ref_idc = (source[kNaluHeaderSize] & 0x60) >> 5; | |
| 329 uint32_t golomb_tmp; | |
| 330 uint32_t bits_tmp; | |
| 331 | |
| 332 // first_mb_in_slice: ue(v) | |
| 333 RETURN_FALSE_ON_FAIL(slice_reader.ReadExponentialGolomb(&golomb_tmp)); | |
| 334 // slice_type: ue(v) | |
| 335 uint32_t slice_type; | |
| 336 RETURN_FALSE_ON_FAIL(slice_reader.ReadExponentialGolomb(&slice_type)); | |
| 337 // slice_type's 5..9 range is used to indicate that all slices of a picture | |
| 338 // have the same value of slice_type % 5, we don't care about that, so we map | |
| 339 // to the corresponding 0..4 range. | |
| 340 slice_type %= 5; | |
| 341 // pic_parameter_set_id: ue(v) | |
| 342 RETURN_FALSE_ON_FAIL(slice_reader.ReadExponentialGolomb(&golomb_tmp)); | |
| 343 if (sps_.separate_colour_plane_flag == 1) { | |
| 344 // colour_plane_id | |
| 345 RETURN_FALSE_ON_FAIL(slice_reader.ReadBits(&bits_tmp, 2)); | |
| 346 } | |
| 347 // frame_num: u(v) | |
| 348 // Represented by log2_max_frame_num_minus4 + 4 bits. | |
| 349 RETURN_FALSE_ON_FAIL( | |
| 350 slice_reader.ReadBits(&bits_tmp, sps_.log2_max_frame_num_minus4 + 4)); | |
| 351 uint32_t field_pic_flag = 0; | |
| 352 if (sps_.frame_mbs_only_flag == 0) { | |
| 353 // field_pic_flag: u(1) | |
| 354 RETURN_FALSE_ON_FAIL(slice_reader.ReadBits(&field_pic_flag, 1)); | |
| 355 if (field_pic_flag != 0) { | |
| 356 // bottom_field_flag: u(1) | |
| 357 RETURN_FALSE_ON_FAIL(slice_reader.ReadBits(&bits_tmp, 1)); | |
| 358 } | |
| 359 } | |
| 360 if (is_idr) { | |
| 361 // idr_pic_id: ue(v) | |
| 362 RETURN_FALSE_ON_FAIL(slice_reader.ReadExponentialGolomb(&golomb_tmp)); | |
| 363 } | |
| 364 // pic_order_cnt_lsb: u(v) | |
| 365 // Represented by sps_.log2_max_pic_order_cnt_lsb_minus4 + 4 bits. | |
| 366 if (sps_.pic_order_cnt_type == 0) { | |
| 367 RETURN_FALSE_ON_FAIL(slice_reader.ReadBits( | |
| 368 &bits_tmp, sps_.log2_max_pic_order_cnt_lsb_minus4 + 4)); | |
| 369 if (pps_.bottom_field_pic_order_in_frame_present_flag && | |
| 370 field_pic_flag == 0) { | |
| 371 // delta_pic_order_cnt_bottom: se(v) | |
| 372 RETURN_FALSE_ON_FAIL(slice_reader.ReadExponentialGolomb(&golomb_tmp)); | |
| 373 } | |
| 374 } | |
| 375 if (sps_.pic_order_cnt_type == 1 && !sps_.delta_pic_order_always_zero_flag) { | |
| 376 // delta_pic_order_cnt[0]: se(v) | |
| 377 RETURN_FALSE_ON_FAIL(slice_reader.ReadExponentialGolomb(&golomb_tmp)); | |
| 378 if (pps_.bottom_field_pic_order_in_frame_present_flag && !field_pic_flag) { | |
| 379 // delta_pic_order_cnt[1]: se(v) | |
| 380 RETURN_FALSE_ON_FAIL(slice_reader.ReadExponentialGolomb(&golomb_tmp)); | |
| 381 } | |
| 382 } | |
| 383 if (pps_.redundant_pic_cnt_present_flag) { | |
| 384 // redundant_pic_cnt: ue(v) | |
| 385 RETURN_FALSE_ON_FAIL(slice_reader.ReadExponentialGolomb(&golomb_tmp)); | |
| 386 } | |
| 387 if (slice_type == kSliceTypeB) { | |
| 388 // direct_spatial_mv_pred_flag: u(1) | |
| 389 RETURN_FALSE_ON_FAIL(slice_reader.ReadBits(&bits_tmp, 1)); | |
| 390 } | |
| 391 if (slice_type == kSliceTypeP || slice_type == kSliceTypeSp || | |
| 392 slice_type == kSliceTypeB) { | |
| 393 uint32_t num_ref_idx_active_override_flag; | |
| 394 // num_ref_idx_active_override_flag: u(1) | |
| 395 RETURN_FALSE_ON_FAIL( | |
| 396 slice_reader.ReadBits(&num_ref_idx_active_override_flag, 1)); | |
| 397 if (num_ref_idx_active_override_flag != 0) { | |
| 398 // num_ref_idx_l0_active_minus1: ue(v) | |
| 399 RETURN_FALSE_ON_FAIL(slice_reader.ReadExponentialGolomb(&golomb_tmp)); | |
| 400 if (slice_type == kSliceTypeB) { | |
| 401 // num_ref_idx_l1_active_minus1: ue(v) | |
| 402 RETURN_FALSE_ON_FAIL(slice_reader.ReadExponentialGolomb(&golomb_tmp)); | |
| 403 } | |
| 404 } | |
| 405 } | |
| 406 // assume nal_unit_type != 20 && nal_unit_type != 21: | |
| 407 RTC_CHECK_NE(nalu_type, 20); | |
| 408 RTC_CHECK_NE(nalu_type, 21); | |
| 409 // if (nal_unit_type == 20 || nal_unit_type == 21) | |
| 410 // ref_pic_list_mvc_modification() | |
| 411 // else | |
| 412 { | |
| 413 // ref_pic_list_modification(): | |
| 414 // |slice_type| checks here don't use named constants as they aren't named | |
| 415 // in the spec for this segment. Keeping them consistent makes it easier to | |
| 416 // verify that they are both the same. | |
| 417 if (slice_type % 5 != 2 && slice_type % 5 != 4) { | |
| 418 // ref_pic_list_modification_flag_l0: u(1) | |
| 419 uint32_t ref_pic_list_modification_flag_l0; | |
| 420 RETURN_FALSE_ON_FAIL( | |
| 421 slice_reader.ReadBits(&ref_pic_list_modification_flag_l0, 1)); | |
| 422 if (ref_pic_list_modification_flag_l0) { | |
| 423 uint32_t modification_of_pic_nums_idc; | |
| 424 do { | |
| 425 // modification_of_pic_nums_idc: ue(v) | |
| 426 RETURN_FALSE_ON_FAIL(slice_reader.ReadExponentialGolomb( | |
| 427 &modification_of_pic_nums_idc)); | |
| 428 if (modification_of_pic_nums_idc == 0 || | |
| 429 modification_of_pic_nums_idc == 1) { | |
| 430 // abs_diff_pic_num_minus1: ue(v) | |
| 431 RETURN_FALSE_ON_FAIL( | |
| 432 slice_reader.ReadExponentialGolomb(&golomb_tmp)); | |
| 433 } else if (modification_of_pic_nums_idc == 2) { | |
| 434 // long_term_pic_num: ue(v) | |
| 435 RETURN_FALSE_ON_FAIL( | |
| 436 slice_reader.ReadExponentialGolomb(&golomb_tmp)); | |
| 437 } | |
| 438 } while (modification_of_pic_nums_idc != 3); | |
| 439 } | |
| 440 } | |
| 441 if (slice_type % 5 == 1) { | |
| 442 // ref_pic_list_modification_flag_l1: u(1) | |
| 443 uint32_t ref_pic_list_modification_flag_l1; | |
| 444 RETURN_FALSE_ON_FAIL( | |
| 445 slice_reader.ReadBits(&ref_pic_list_modification_flag_l1, 1)); | |
| 446 if (ref_pic_list_modification_flag_l1) { | |
| 447 uint32_t modification_of_pic_nums_idc; | |
| 448 do { | |
| 449 // modification_of_pic_nums_idc: ue(v) | |
| 450 RETURN_FALSE_ON_FAIL(slice_reader.ReadExponentialGolomb( | |
| 451 &modification_of_pic_nums_idc)); | |
| 452 if (modification_of_pic_nums_idc == 0 || | |
| 453 modification_of_pic_nums_idc == 1) { | |
| 454 // abs_diff_pic_num_minus1: ue(v) | |
| 455 RETURN_FALSE_ON_FAIL( | |
| 456 slice_reader.ReadExponentialGolomb(&golomb_tmp)); | |
| 457 } else if (modification_of_pic_nums_idc == 2) { | |
| 458 // long_term_pic_num: ue(v) | |
| 459 RETURN_FALSE_ON_FAIL( | |
| 460 slice_reader.ReadExponentialGolomb(&golomb_tmp)); | |
| 461 } | |
| 462 } while (modification_of_pic_nums_idc != 3); | |
| 463 } | |
| 464 } | |
| 465 } | |
| 466 // TODO(pbos): Do we need support for pred_weight_table()? | |
| 467 RTC_CHECK(!((pps_.weighted_pred_flag && | |
| 468 (slice_type == kSliceTypeP || slice_type == kSliceTypeSp)) || | |
| 469 (pps_.weighted_bipred_idc != 0 && slice_type == kSliceTypeB))) | |
| 470 << "Missing support for pred_weight_table()."; | |
| 471 // if ((weighted_pred_flag && (slice_type == P || slice_type == SP)) || | |
| 472 // (weighted_bipred_idc == 1 && slice_type == B)) { | |
| 473 // pred_weight_table() | |
| 474 // } | |
| 475 if (nal_ref_idc != 0) { | |
| 476 // dec_ref_pic_marking(): | |
| 477 if (is_idr) { | |
| 478 // no_output_of_prior_pics_flag: u(1) | |
| 479 // long_term_reference_flag: u(1) | |
| 480 RETURN_FALSE_ON_FAIL(slice_reader.ReadBits(&bits_tmp, 2)); | |
| 481 } else { | |
| 482 // adaptive_ref_pic_marking_mode_flag: u(1) | |
| 483 uint32_t adaptive_ref_pic_marking_mode_flag; | |
| 484 RETURN_FALSE_ON_FAIL( | |
| 485 slice_reader.ReadBits(&adaptive_ref_pic_marking_mode_flag, 1)); | |
| 486 if (adaptive_ref_pic_marking_mode_flag) { | |
| 487 uint32_t memory_management_control_operation; | |
| 488 do { | |
| 489 // memory_management_control_operation: ue(v) | |
| 490 RETURN_FALSE_ON_FAIL(slice_reader.ReadExponentialGolomb( | |
| 491 &memory_management_control_operation)); | |
| 492 if (memory_management_control_operation == 1 || | |
| 493 memory_management_control_operation == 3) { | |
| 494 // difference_of_pic_nums_minus1: ue(v) | |
| 495 RETURN_FALSE_ON_FAIL( | |
| 496 slice_reader.ReadExponentialGolomb(&golomb_tmp)); | |
| 497 } | |
| 498 if (memory_management_control_operation == 2) { | |
| 499 // long_term_pic_num: ue(v) | |
| 500 RETURN_FALSE_ON_FAIL( | |
| 501 slice_reader.ReadExponentialGolomb(&golomb_tmp)); | |
| 502 } | |
| 503 if (memory_management_control_operation == 3 || | |
| 504 memory_management_control_operation == 6) { | |
| 505 // long_term_frame_idx: ue(v) | |
| 506 RETURN_FALSE_ON_FAIL( | |
| 507 slice_reader.ReadExponentialGolomb(&golomb_tmp)); | |
| 508 } | |
| 509 if (memory_management_control_operation == 4) { | |
| 510 // max_long_term_frame_idx_plus1: ue(v) | |
| 511 RETURN_FALSE_ON_FAIL( | |
| 512 slice_reader.ReadExponentialGolomb(&golomb_tmp)); | |
| 513 } | |
| 514 } while (memory_management_control_operation != 0); | |
| 515 } | |
| 516 } | |
| 517 } | |
| 518 // cabac not supported: entropy_coding_mode_flag == 0 asserted above. | |
| 519 // if (entropy_coding_mode_flag && slice_type != I && slice_type != SI) | |
| 520 // cabac_init_idc | |
| 521 RETURN_FALSE_ON_FAIL( | |
| 522 slice_reader.ReadSignedExponentialGolomb(&last_slice_qp_delta_)); | |
| 523 last_slice_qp_delta_parsed_ = true; | |
| 524 return true; | |
| 525 } | |
| 526 | |
| 527 void H264BitstreamParser::ParseSlice(const uint8_t* slice, size_t length) { | |
| 528 uint8_t nalu_type = slice[4] & kNaluTypeMask; | |
| 529 switch (nalu_type) { | |
| 530 case kNaluSps: | |
| 531 RTC_CHECK(ParseSpsNalu(slice, length)) | |
| 532 << "Failed to parse bitstream SPS."; | |
| 533 break; | |
| 534 case kNaluPps: | |
| 535 RTC_CHECK(ParsePpsNalu(slice, length)) | |
| 536 << "Failed to parse bitstream PPS."; | |
| 537 break; | |
| 538 default: | |
| 539 RTC_CHECK(ParseNonParameterSetNalu(slice, length, nalu_type)) | |
| 540 << "Failed to parse picture slice."; | |
| 541 break; | |
| 542 } | |
| 543 } | |
| 544 | |
| 545 void H264BitstreamParser::ParseBitstream(const uint8_t* bitstream, | |
| 546 size_t length) { | |
| 547 RTC_CHECK_GE(length, 4u); | |
| 548 std::vector<size_t> slice_markers = FindNaluStartSequences(bitstream, length); | |
| 549 RTC_CHECK(!slice_markers.empty()); | |
| 550 for (size_t i = 0; i < slice_markers.size() - 1; ++i) { | |
| 551 ParseSlice(bitstream + slice_markers[i], | |
| 552 slice_markers[i + 1] - slice_markers[i]); | |
| 553 } | |
| 554 // Parse the last slice. | |
| 555 ParseSlice(bitstream + slice_markers.back(), length - slice_markers.back()); | |
| 556 } | |
| 557 | |
| 558 bool H264BitstreamParser::GetLastSliceQp(int* qp) const { | |
| 559 if (!last_slice_qp_delta_parsed_) | |
| 560 return false; | |
| 561 *qp = 26 + pps_.pic_init_qp_minus26 + last_slice_qp_delta_; | |
| 562 return true; | |
| 563 } | |
| 564 | |
| 565 } // namespace webrtc | |
| OLD | NEW |
|---|
Chromium Code Reviews
Issue 2007553003:
Move H264BitstreamParser to video_coding. (Closed)
Base URL: https://chromium.googlesource.com/external/webrtc.git@master