15d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles)// Copyright 2014 The Chromium Authors. All rights reserved. 25d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles)// Use of this source code is governed by a BSD-style license that can be 35d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles)// found in the LICENSE file. 45d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) 51320f92c476a1ad9d19dba2a48c72b75566198e9Primiano Tucci#include "media/formats/mpeg/mpeg1_audio_stream_parser.h" 65d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) 75d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles)namespace media { 85d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) 91320f92c476a1ad9d19dba2a48c72b75566198e9Primiano Tuccistatic const uint32 kMPEG1StartCodeMask = 0xffe00000; 105d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) 115d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles)// Map that determines which bitrate_index & channel_mode combinations 125d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles)// are allowed. 135d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles)// Derived from: http://mpgedit.org/mpgedit/mpeg_format/MP3Format.html 145d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles)static const bool kIsAllowed[17][4] = { 155d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) { true, true, true, true }, // free 165d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) { true, false, false, false }, // 32 175d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) { true, false, false, false }, // 48 185d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) { true, false, false, false }, // 56 195d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) { true, true, true, true }, // 64 205d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) { true, false, false, false }, // 80 215d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) { true, true, true, true }, // 96 225d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) { true, true, true, true }, // 112 235d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) { true, true, true, true }, // 128 245d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) { true, true, true, true }, // 160 255d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) { true, true, true, true }, // 192 265d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) { false, true, true, true }, // 224 275d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) { false, true, true, true }, // 256 285d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) { false, true, true, true }, // 320 295d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) { false, true, true, true }, // 384 305d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) { false, false, false, false } // bad 315d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles)}; 325d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) 335d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles)// Maps version and layer information in the frame header 345d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles)// into an index for the |kBitrateMap|. 355d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles)// Derived from: http://mpgedit.org/mpgedit/mpeg_format/MP3Format.html 365d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles)static const int kVersionLayerMap[4][4] = { 375d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) // { reserved, L3, L2, L1 } 385d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) { 5, 4, 4, 3 }, // MPEG 2.5 395d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) { 5, 5, 5, 5 }, // reserved 405d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) { 5, 4, 4, 3 }, // MPEG 2 415d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) { 5, 2, 1, 0 } // MPEG 1 425d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles)}; 435d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) 445d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles)// Maps the bitrate index field in the header and an index 455d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles)// from |kVersionLayerMap| to a frame bitrate. 465d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles)// Derived from: http://mpgedit.org/mpgedit/mpeg_format/MP3Format.html 475d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles)static const int kBitrateMap[16][6] = { 485d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) // { V1L1, V1L2, V1L3, V2L1, V2L2 & V2L3, reserved } 495d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) { 0, 0, 0, 0, 0, 0 }, 505d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) { 32, 32, 32, 32, 8, 0 }, 515d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) { 64, 48, 40, 48, 16, 0 }, 525d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) { 96, 56, 48, 56, 24, 0 }, 535d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) { 128, 64, 56, 64, 32, 0 }, 545d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) { 160, 80, 64, 80, 40, 0 }, 555d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) { 192, 96, 80, 96, 48, 0 }, 565d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) { 224, 112, 96, 112, 56, 0 }, 575d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) { 256, 128, 112, 128, 64, 0 }, 585d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) { 288, 160, 128, 144, 80, 0 }, 595d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) { 320, 192, 160, 160, 96, 0 }, 605d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) { 352, 224, 192, 176, 112, 0 }, 615d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) { 384, 256, 224, 192, 128, 0 }, 625d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) { 416, 320, 256, 224, 144, 0 }, 635d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) { 448, 384, 320, 256, 160, 0 }, 645d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) { 0, 0, 0, 0, 0} 655d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles)}; 665d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) 675d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles)// Maps the sample rate index and version fields from the frame header 685d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles)// to a sample rate. 695d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles)// Derived from: http://mpgedit.org/mpgedit/mpeg_format/MP3Format.html 705d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles)static const int kSampleRateMap[4][4] = { 715d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) // { V2.5, reserved, V2, V1 } 725d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) { 11025, 0, 22050, 44100 }, 735d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) { 12000, 0, 24000, 48000 }, 745d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) { 8000, 0, 16000, 32000 }, 755d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) { 0, 0, 0, 0 } 765d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles)}; 775d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) 780529e5d033099cbfc42635f6f6183833b09dff6eBen Murdoch// Offset in bytes from the end of the MP3 header to "Xing" or "Info" tags which 790529e5d033099cbfc42635f6f6183833b09dff6eBen Murdoch// indicate a frame is silent metadata frame. Values taken from FFmpeg. 800529e5d033099cbfc42635f6f6183833b09dff6eBen Murdochstatic const int kXingHeaderMap[2][2] = {{32, 17}, {17, 9}}; 810529e5d033099cbfc42635f6f6183833b09dff6eBen Murdoch 825d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles)// Frame header field constants. 835d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles)static const int kBitrateFree = 0; 845d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles)static const int kBitrateBad = 0xf; 855d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles)static const int kSampleRateReserved = 3; 860529e5d033099cbfc42635f6f6183833b09dff6eBen Murdochstatic const int kCodecDelay = 529; 875d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) 881320f92c476a1ad9d19dba2a48c72b75566198e9Primiano Tucci// static 891320f92c476a1ad9d19dba2a48c72b75566198e9Primiano Tuccibool MPEG1AudioStreamParser::ParseHeader( 901320f92c476a1ad9d19dba2a48c72b75566198e9Primiano Tucci const LogCB& log_cb, 911320f92c476a1ad9d19dba2a48c72b75566198e9Primiano Tucci const uint8* data, 921320f92c476a1ad9d19dba2a48c72b75566198e9Primiano Tucci Header* header) { 931320f92c476a1ad9d19dba2a48c72b75566198e9Primiano Tucci BitReader reader(data, kHeaderSize); 945d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) int sync; 955d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) int version; 965d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) int layer; 975d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) int is_protected; 985d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) int bitrate_index; 995d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) int sample_rate_index; 1005d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) int has_padding; 1015d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) int is_private; 1025d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) int channel_mode; 1035d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) int other_flags; 1045d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) 1055d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) if (!reader.ReadBits(11, &sync) || 1065d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) !reader.ReadBits(2, &version) || 1075d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) !reader.ReadBits(2, &layer) || 1085d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) !reader.ReadBits(1, &is_protected) || 1095d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) !reader.ReadBits(4, &bitrate_index) || 1105d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) !reader.ReadBits(2, &sample_rate_index) || 1115d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) !reader.ReadBits(1, &has_padding) || 1125d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) !reader.ReadBits(1, &is_private) || 1135d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) !reader.ReadBits(2, &channel_mode) || 1145d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) !reader.ReadBits(6, &other_flags)) { 1151320f92c476a1ad9d19dba2a48c72b75566198e9Primiano Tucci return false; 1165d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) } 1175d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) 1185d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) DVLOG(2) << "Header data :" << std::hex 1195d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) << " sync 0x" << sync 1205d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) << " version 0x" << version 1215d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) << " layer 0x" << layer 1225d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) << " bitrate_index 0x" << bitrate_index 1235d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) << " sample_rate_index 0x" << sample_rate_index 1245d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) << " channel_mode 0x" << channel_mode; 1255d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) 1265d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) if (sync != 0x7ff || 1275d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) version == kVersionReserved || 1285d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) layer == kLayerReserved || 1295d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) bitrate_index == kBitrateFree || bitrate_index == kBitrateBad || 1305d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) sample_rate_index == kSampleRateReserved) { 1311320f92c476a1ad9d19dba2a48c72b75566198e9Primiano Tucci MEDIA_LOG(log_cb) << "Invalid header data :" << std::hex 1321320f92c476a1ad9d19dba2a48c72b75566198e9Primiano Tucci << " sync 0x" << sync 1331320f92c476a1ad9d19dba2a48c72b75566198e9Primiano Tucci << " version 0x" << version 1341320f92c476a1ad9d19dba2a48c72b75566198e9Primiano Tucci << " layer 0x" << layer 1351320f92c476a1ad9d19dba2a48c72b75566198e9Primiano Tucci << " bitrate_index 0x" << bitrate_index 1361320f92c476a1ad9d19dba2a48c72b75566198e9Primiano Tucci << " sample_rate_index 0x" << sample_rate_index 1371320f92c476a1ad9d19dba2a48c72b75566198e9Primiano Tucci << " channel_mode 0x" << channel_mode; 1381320f92c476a1ad9d19dba2a48c72b75566198e9Primiano Tucci return false; 1395d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) } 1405d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) 1415d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) if (layer == kLayer2 && kIsAllowed[bitrate_index][channel_mode]) { 1421320f92c476a1ad9d19dba2a48c72b75566198e9Primiano Tucci MEDIA_LOG(log_cb) << "Invalid (bitrate_index, channel_mode) combination :" 1431320f92c476a1ad9d19dba2a48c72b75566198e9Primiano Tucci << std::hex 1441320f92c476a1ad9d19dba2a48c72b75566198e9Primiano Tucci << " bitrate_index " << bitrate_index 1451320f92c476a1ad9d19dba2a48c72b75566198e9Primiano Tucci << " channel_mode " << channel_mode; 1461320f92c476a1ad9d19dba2a48c72b75566198e9Primiano Tucci return false; 1475d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) } 1485d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) 1495d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) int bitrate = kBitrateMap[bitrate_index][kVersionLayerMap[version][layer]]; 1505d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) 1515d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) if (bitrate == 0) { 1521320f92c476a1ad9d19dba2a48c72b75566198e9Primiano Tucci MEDIA_LOG(log_cb) << "Invalid bitrate :" << std::hex 1531320f92c476a1ad9d19dba2a48c72b75566198e9Primiano Tucci << " version " << version 1541320f92c476a1ad9d19dba2a48c72b75566198e9Primiano Tucci << " layer " << layer 1551320f92c476a1ad9d19dba2a48c72b75566198e9Primiano Tucci << " bitrate_index " << bitrate_index; 1561320f92c476a1ad9d19dba2a48c72b75566198e9Primiano Tucci return false; 1575d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) } 1585d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) 1595d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) DVLOG(2) << " bitrate " << bitrate; 1605d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) 1615d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) int frame_sample_rate = kSampleRateMap[sample_rate_index][version]; 1625d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) if (frame_sample_rate == 0) { 1631320f92c476a1ad9d19dba2a48c72b75566198e9Primiano Tucci MEDIA_LOG(log_cb) << "Invalid sample rate :" << std::hex 1641320f92c476a1ad9d19dba2a48c72b75566198e9Primiano Tucci << " version " << version 1651320f92c476a1ad9d19dba2a48c72b75566198e9Primiano Tucci << " sample_rate_index " << sample_rate_index; 1661320f92c476a1ad9d19dba2a48c72b75566198e9Primiano Tucci return false; 1675d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) } 1681320f92c476a1ad9d19dba2a48c72b75566198e9Primiano Tucci header->sample_rate = frame_sample_rate; 1695d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) 1705d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) // http://teslabs.com/openplayer/docs/docs/specs/mp3_structure2.pdf 1715d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) // Table 2.1.5 1725d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) int samples_per_frame; 1735d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) switch (layer) { 1745d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) case kLayer1: 1755d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) samples_per_frame = 384; 1765d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) break; 1775d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) 1785d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) case kLayer2: 1795d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) samples_per_frame = 1152; 1805d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) break; 1815d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) 1825d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) case kLayer3: 1835d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) if (version == kVersion2 || version == kVersion2_5) 1845d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) samples_per_frame = 576; 1855d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) else 1865d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) samples_per_frame = 1152; 1875d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) break; 1885d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) 1895d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) default: 1901320f92c476a1ad9d19dba2a48c72b75566198e9Primiano Tucci return false; 1915d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) } 1921320f92c476a1ad9d19dba2a48c72b75566198e9Primiano Tucci header->sample_count = samples_per_frame; 1935d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) 1945d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) // http://teslabs.com/openplayer/docs/docs/specs/mp3_structure2.pdf 1955d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) // Text just below Table 2.1.5. 1965d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) if (layer == kLayer1) { 1975d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) // This formulation is a slight variation on the equation below, 1985d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) // but has slightly different truncation characteristics to deal 1995d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) // with the fact that Layer 1 has 4 byte "slots" instead of single 2005d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) // byte ones. 2011320f92c476a1ad9d19dba2a48c72b75566198e9Primiano Tucci header->frame_size = 4 * (12 * bitrate * 1000 / frame_sample_rate); 2025d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) } else { 2031320f92c476a1ad9d19dba2a48c72b75566198e9Primiano Tucci header->frame_size = 2045d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) ((samples_per_frame / 8) * bitrate * 1000) / frame_sample_rate; 2055d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) } 2065d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) 2075d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) if (has_padding) 2081320f92c476a1ad9d19dba2a48c72b75566198e9Primiano Tucci header->frame_size += (layer == kLayer1) ? 4 : 1; 2095d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) 2101320f92c476a1ad9d19dba2a48c72b75566198e9Primiano Tucci // Map Stereo(0), Joint Stereo(1), and Dual Channel (2) to 2111320f92c476a1ad9d19dba2a48c72b75566198e9Primiano Tucci // CHANNEL_LAYOUT_STEREO and Single Channel (3) to CHANNEL_LAYOUT_MONO. 2121320f92c476a1ad9d19dba2a48c72b75566198e9Primiano Tucci header->channel_layout = 2131320f92c476a1ad9d19dba2a48c72b75566198e9Primiano Tucci (channel_mode == 3) ? CHANNEL_LAYOUT_MONO : CHANNEL_LAYOUT_STEREO; 2141320f92c476a1ad9d19dba2a48c72b75566198e9Primiano Tucci 2151320f92c476a1ad9d19dba2a48c72b75566198e9Primiano Tucci header->version = static_cast<Version>(version); 2161320f92c476a1ad9d19dba2a48c72b75566198e9Primiano Tucci header->layer = static_cast<Layer>(layer); 2171320f92c476a1ad9d19dba2a48c72b75566198e9Primiano Tucci header->channel_mode = channel_mode; 2181320f92c476a1ad9d19dba2a48c72b75566198e9Primiano Tucci return true; 2191320f92c476a1ad9d19dba2a48c72b75566198e9Primiano Tucci} 2201320f92c476a1ad9d19dba2a48c72b75566198e9Primiano Tucci 2211320f92c476a1ad9d19dba2a48c72b75566198e9Primiano Tucci 2221320f92c476a1ad9d19dba2a48c72b75566198e9Primiano TucciMPEG1AudioStreamParser::MPEG1AudioStreamParser() 2231320f92c476a1ad9d19dba2a48c72b75566198e9Primiano Tucci : MPEGAudioStreamParserBase(kMPEG1StartCodeMask, kCodecMP3, kCodecDelay) {} 2241320f92c476a1ad9d19dba2a48c72b75566198e9Primiano Tucci 2251320f92c476a1ad9d19dba2a48c72b75566198e9Primiano TucciMPEG1AudioStreamParser::~MPEG1AudioStreamParser() {} 2261320f92c476a1ad9d19dba2a48c72b75566198e9Primiano Tucci 2271320f92c476a1ad9d19dba2a48c72b75566198e9Primiano Tucciint MPEG1AudioStreamParser::ParseFrameHeader(const uint8* data, 2281320f92c476a1ad9d19dba2a48c72b75566198e9Primiano Tucci int size, 2291320f92c476a1ad9d19dba2a48c72b75566198e9Primiano Tucci int* frame_size, 2301320f92c476a1ad9d19dba2a48c72b75566198e9Primiano Tucci int* sample_rate, 2311320f92c476a1ad9d19dba2a48c72b75566198e9Primiano Tucci ChannelLayout* channel_layout, 2321320f92c476a1ad9d19dba2a48c72b75566198e9Primiano Tucci int* sample_count, 2331320f92c476a1ad9d19dba2a48c72b75566198e9Primiano Tucci bool* metadata_frame) const { 2341320f92c476a1ad9d19dba2a48c72b75566198e9Primiano Tucci DCHECK(data); 2351320f92c476a1ad9d19dba2a48c72b75566198e9Primiano Tucci DCHECK_GE(size, 0); 2361320f92c476a1ad9d19dba2a48c72b75566198e9Primiano Tucci DCHECK(frame_size); 2371320f92c476a1ad9d19dba2a48c72b75566198e9Primiano Tucci 2381320f92c476a1ad9d19dba2a48c72b75566198e9Primiano Tucci if (size < kHeaderSize) 2391320f92c476a1ad9d19dba2a48c72b75566198e9Primiano Tucci return 0; 2405d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) 2411320f92c476a1ad9d19dba2a48c72b75566198e9Primiano Tucci Header header; 2421320f92c476a1ad9d19dba2a48c72b75566198e9Primiano Tucci if (!ParseHeader(log_cb(), data, &header)) 2431320f92c476a1ad9d19dba2a48c72b75566198e9Primiano Tucci return -1; 2441320f92c476a1ad9d19dba2a48c72b75566198e9Primiano Tucci 2451320f92c476a1ad9d19dba2a48c72b75566198e9Primiano Tucci *frame_size = header.frame_size; 2461320f92c476a1ad9d19dba2a48c72b75566198e9Primiano Tucci if (sample_rate) 2471320f92c476a1ad9d19dba2a48c72b75566198e9Primiano Tucci *sample_rate = header.sample_rate; 2481320f92c476a1ad9d19dba2a48c72b75566198e9Primiano Tucci if (sample_count) 2491320f92c476a1ad9d19dba2a48c72b75566198e9Primiano Tucci *sample_count = header.sample_count; 2501320f92c476a1ad9d19dba2a48c72b75566198e9Primiano Tucci if (channel_layout) 2511320f92c476a1ad9d19dba2a48c72b75566198e9Primiano Tucci *channel_layout = header.channel_layout; 2520529e5d033099cbfc42635f6f6183833b09dff6eBen Murdoch if (metadata_frame) 2530529e5d033099cbfc42635f6f6183833b09dff6eBen Murdoch *metadata_frame = false; 2540529e5d033099cbfc42635f6f6183833b09dff6eBen Murdoch 2551320f92c476a1ad9d19dba2a48c72b75566198e9Primiano Tucci const int header_bytes_read = kHeaderSize; 2561320f92c476a1ad9d19dba2a48c72b75566198e9Primiano Tucci if (header.layer != kLayer3) 2570529e5d033099cbfc42635f6f6183833b09dff6eBen Murdoch return header_bytes_read; 2580529e5d033099cbfc42635f6f6183833b09dff6eBen Murdoch 2590529e5d033099cbfc42635f6f6183833b09dff6eBen Murdoch // Check if this is a XING frame and tell the base parser to skip it if so. 2600529e5d033099cbfc42635f6f6183833b09dff6eBen Murdoch const int xing_header_index = 2611320f92c476a1ad9d19dba2a48c72b75566198e9Primiano Tucci kXingHeaderMap[header.version == kVersion2 || 2621320f92c476a1ad9d19dba2a48c72b75566198e9Primiano Tucci header.version == kVersion2_5][header.channel_mode == 3]; 2630529e5d033099cbfc42635f6f6183833b09dff6eBen Murdoch uint32_t tag = 0; 2640529e5d033099cbfc42635f6f6183833b09dff6eBen Murdoch 2650529e5d033099cbfc42635f6f6183833b09dff6eBen Murdoch // It's not a XING frame if the frame isn't big enough to be one. 2660529e5d033099cbfc42635f6f6183833b09dff6eBen Murdoch if (*frame_size < 2670529e5d033099cbfc42635f6f6183833b09dff6eBen Murdoch header_bytes_read + xing_header_index + static_cast<int>(sizeof(tag))) { 2680529e5d033099cbfc42635f6f6183833b09dff6eBen Murdoch return header_bytes_read; 2690529e5d033099cbfc42635f6f6183833b09dff6eBen Murdoch } 2700529e5d033099cbfc42635f6f6183833b09dff6eBen Murdoch 2710529e5d033099cbfc42635f6f6183833b09dff6eBen Murdoch // If we don't have enough data available to check, return 0 so frame parsing 2720529e5d033099cbfc42635f6f6183833b09dff6eBen Murdoch // will be retried once more data is available. 2731320f92c476a1ad9d19dba2a48c72b75566198e9Primiano Tucci BitReader reader(data + header_bytes_read, size - header_bytes_read); 2740529e5d033099cbfc42635f6f6183833b09dff6eBen Murdoch if (!reader.SkipBits(xing_header_index * 8) || 2750529e5d033099cbfc42635f6f6183833b09dff6eBen Murdoch !reader.ReadBits(sizeof(tag) * 8, &tag)) { 2760529e5d033099cbfc42635f6f6183833b09dff6eBen Murdoch return 0; 2770529e5d033099cbfc42635f6f6183833b09dff6eBen Murdoch } 2780529e5d033099cbfc42635f6f6183833b09dff6eBen Murdoch 2790529e5d033099cbfc42635f6f6183833b09dff6eBen Murdoch // Check to see if the tag contains 'Xing' or 'Info' 2800529e5d033099cbfc42635f6f6183833b09dff6eBen Murdoch if (tag == 0x496e666f || tag == 0x58696e67) { 2810529e5d033099cbfc42635f6f6183833b09dff6eBen Murdoch MEDIA_LOG(log_cb()) << "Skipping XING header."; 2820529e5d033099cbfc42635f6f6183833b09dff6eBen Murdoch if (metadata_frame) 2830529e5d033099cbfc42635f6f6183833b09dff6eBen Murdoch *metadata_frame = true; 2841320f92c476a1ad9d19dba2a48c72b75566198e9Primiano Tucci return header_bytes_read + reader.bits_read() / 8; 2850529e5d033099cbfc42635f6f6183833b09dff6eBen Murdoch } 2860529e5d033099cbfc42635f6f6183833b09dff6eBen Murdoch 2870529e5d033099cbfc42635f6f6183833b09dff6eBen Murdoch // If it wasn't a XING frame, just return the number consumed bytes. 2880529e5d033099cbfc42635f6f6183833b09dff6eBen Murdoch return header_bytes_read; 2895d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles)} 2905d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles) 2915d1f7b1de12d16ceb2c938c56701a3e8bfa558f7Torne (Richard Coles)} // namespace media 292