1/* 2 * Copyright (C) 2010 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17//#define LOG_NDEBUG 0 18#define LOG_TAG "avc_utils" 19#include <utils/Log.h> 20 21#include "include/avc_utils.h" 22 23#include <media/stagefright/foundation/ABitReader.h> 24#include <media/stagefright/foundation/ADebug.h> 25#include <media/stagefright/foundation/hexdump.h> 26#include <media/stagefright/MediaDefs.h> 27#include <media/stagefright/MediaErrors.h> 28#include <media/stagefright/MetaData.h> 29#include <utils/misc.h> 30 31namespace android { 32 33unsigned parseUE(ABitReader *br) { 34 unsigned numZeroes = 0; 35 while (br->getBits(1) == 0) { 36 ++numZeroes; 37 } 38 39 unsigned x = br->getBits(numZeroes); 40 41 return x + (1u << numZeroes) - 1; 42} 43 44unsigned parseUEWithFallback(ABitReader *br, unsigned fallback) { 45 unsigned numZeroes = 0; 46 while (br->getBitsWithFallback(1, 1) == 0) { 47 ++numZeroes; 48 } 49 uint32_t x; 50 if (numZeroes < 32) { 51 if (br->getBitsGraceful(numZeroes, &x)) { 52 return x + (1u << numZeroes) - 1; 53 } else { 54 return fallback; 55 } 56 } else { 57 br->skipBits(numZeroes); 58 return fallback; 59 } 60} 61 62signed parseSE(ABitReader *br) { 63 unsigned codeNum = parseUE(br); 64 65 return (codeNum & 1) ? (codeNum + 1) / 2 : -signed(codeNum / 2); 66} 67 68signed parseSEWithFallback(ABitReader *br, signed fallback) { 69 // NOTE: parseUE cannot normally return ~0 as the max supported value is 0xFFFE 70 unsigned codeNum = parseUEWithFallback(br, ~0U); 71 if (codeNum == ~0U) { 72 return fallback; 73 } 74 return (codeNum & 1) ? (codeNum + 1) / 2 : -signed(codeNum / 2); 75} 76 77static void skipScalingList(ABitReader *br, size_t sizeOfScalingList) { 78 size_t lastScale = 8; 79 size_t nextScale = 8; 80 for (size_t j = 0; j < sizeOfScalingList; ++j) { 81 if (nextScale != 0) { 82 signed delta_scale = parseSE(br); 83 nextScale = (lastScale + delta_scale + 256) % 256; 84 } 85 86 lastScale = (nextScale == 0) ? lastScale : nextScale; 87 } 88} 89 90// Determine video dimensions from the sequence parameterset. 91void FindAVCDimensions( 92 const sp<ABuffer> &seqParamSet, 93 int32_t *width, int32_t *height, 94 int32_t *sarWidth, int32_t *sarHeight) { 95 ABitReader br(seqParamSet->data() + 1, seqParamSet->size() - 1); 96 97 unsigned profile_idc = br.getBits(8); 98 br.skipBits(16); 99 parseUE(&br); // seq_parameter_set_id 100 101 unsigned chroma_format_idc = 1; // 4:2:0 chroma format 102 103 if (profile_idc == 100 || profile_idc == 110 104 || profile_idc == 122 || profile_idc == 244 105 || profile_idc == 44 || profile_idc == 83 || profile_idc == 86) { 106 chroma_format_idc = parseUE(&br); 107 if (chroma_format_idc == 3) { 108 br.skipBits(1); // residual_colour_transform_flag 109 } 110 parseUE(&br); // bit_depth_luma_minus8 111 parseUE(&br); // bit_depth_chroma_minus8 112 br.skipBits(1); // qpprime_y_zero_transform_bypass_flag 113 114 if (br.getBits(1)) { // seq_scaling_matrix_present_flag 115 for (size_t i = 0; i < 8; ++i) { 116 if (br.getBits(1)) { // seq_scaling_list_present_flag[i] 117 118 // WARNING: the code below has not ever been exercised... 119 // need a real-world example. 120 121 if (i < 6) { 122 // ScalingList4x4[i],16,... 123 skipScalingList(&br, 16); 124 } else { 125 // ScalingList8x8[i-6],64,... 126 skipScalingList(&br, 64); 127 } 128 } 129 } 130 } 131 } 132 133 parseUE(&br); // log2_max_frame_num_minus4 134 unsigned pic_order_cnt_type = parseUE(&br); 135 136 if (pic_order_cnt_type == 0) { 137 parseUE(&br); // log2_max_pic_order_cnt_lsb_minus4 138 } else if (pic_order_cnt_type == 1) { 139 // offset_for_non_ref_pic, offset_for_top_to_bottom_field and 140 // offset_for_ref_frame are technically se(v), but since we are 141 // just skipping over them the midpoint does not matter. 142 143 br.getBits(1); // delta_pic_order_always_zero_flag 144 parseUE(&br); // offset_for_non_ref_pic 145 parseUE(&br); // offset_for_top_to_bottom_field 146 147 unsigned num_ref_frames_in_pic_order_cnt_cycle = parseUE(&br); 148 for (unsigned i = 0; i < num_ref_frames_in_pic_order_cnt_cycle; ++i) { 149 parseUE(&br); // offset_for_ref_frame 150 } 151 } 152 153 parseUE(&br); // num_ref_frames 154 br.getBits(1); // gaps_in_frame_num_value_allowed_flag 155 156 unsigned pic_width_in_mbs_minus1 = parseUE(&br); 157 unsigned pic_height_in_map_units_minus1 = parseUE(&br); 158 unsigned frame_mbs_only_flag = br.getBits(1); 159 160 *width = pic_width_in_mbs_minus1 * 16 + 16; 161 162 *height = (2 - frame_mbs_only_flag) 163 * (pic_height_in_map_units_minus1 * 16 + 16); 164 165 if (!frame_mbs_only_flag) { 166 br.getBits(1); // mb_adaptive_frame_field_flag 167 } 168 169 br.getBits(1); // direct_8x8_inference_flag 170 171 if (br.getBits(1)) { // frame_cropping_flag 172 unsigned frame_crop_left_offset = parseUE(&br); 173 unsigned frame_crop_right_offset = parseUE(&br); 174 unsigned frame_crop_top_offset = parseUE(&br); 175 unsigned frame_crop_bottom_offset = parseUE(&br); 176 177 unsigned cropUnitX, cropUnitY; 178 if (chroma_format_idc == 0 /* monochrome */) { 179 cropUnitX = 1; 180 cropUnitY = 2 - frame_mbs_only_flag; 181 } else { 182 unsigned subWidthC = (chroma_format_idc == 3) ? 1 : 2; 183 unsigned subHeightC = (chroma_format_idc == 1) ? 2 : 1; 184 185 cropUnitX = subWidthC; 186 cropUnitY = subHeightC * (2 - frame_mbs_only_flag); 187 } 188 189 ALOGV("frame_crop = (%u, %u, %u, %u), cropUnitX = %u, cropUnitY = %u", 190 frame_crop_left_offset, frame_crop_right_offset, 191 frame_crop_top_offset, frame_crop_bottom_offset, 192 cropUnitX, cropUnitY); 193 194 *width -= 195 (frame_crop_left_offset + frame_crop_right_offset) * cropUnitX; 196 *height -= 197 (frame_crop_top_offset + frame_crop_bottom_offset) * cropUnitY; 198 } 199 200 if (sarWidth != NULL) { 201 *sarWidth = 0; 202 } 203 204 if (sarHeight != NULL) { 205 *sarHeight = 0; 206 } 207 208 if (br.getBits(1)) { // vui_parameters_present_flag 209 unsigned sar_width = 0, sar_height = 0; 210 211 if (br.getBits(1)) { // aspect_ratio_info_present_flag 212 unsigned aspect_ratio_idc = br.getBits(8); 213 214 if (aspect_ratio_idc == 255 /* extendedSAR */) { 215 sar_width = br.getBits(16); 216 sar_height = br.getBits(16); 217 } else { 218 static const struct { unsigned width, height; } kFixedSARs[] = { 219 { 0, 0 }, // Invalid 220 { 1, 1 }, 221 { 12, 11 }, 222 { 10, 11 }, 223 { 16, 11 }, 224 { 40, 33 }, 225 { 24, 11 }, 226 { 20, 11 }, 227 { 32, 11 }, 228 { 80, 33 }, 229 { 18, 11 }, 230 { 15, 11 }, 231 { 64, 33 }, 232 { 160, 99 }, 233 { 4, 3 }, 234 { 3, 2 }, 235 { 2, 1 }, 236 }; 237 238 if (aspect_ratio_idc > 0 && aspect_ratio_idc < NELEM(kFixedSARs)) { 239 sar_width = kFixedSARs[aspect_ratio_idc].width; 240 sar_height = kFixedSARs[aspect_ratio_idc].height; 241 } 242 } 243 } 244 245 ALOGV("sample aspect ratio = %u : %u", sar_width, sar_height); 246 247 if (sarWidth != NULL) { 248 *sarWidth = sar_width; 249 } 250 251 if (sarHeight != NULL) { 252 *sarHeight = sar_height; 253 } 254 } 255} 256 257status_t getNextNALUnit( 258 const uint8_t **_data, size_t *_size, 259 const uint8_t **nalStart, size_t *nalSize, 260 bool startCodeFollows) { 261 const uint8_t *data = *_data; 262 size_t size = *_size; 263 264 *nalStart = NULL; 265 *nalSize = 0; 266 267 if (size < 3) { 268 return -EAGAIN; 269 } 270 271 size_t offset = 0; 272 273 // A valid startcode consists of at least two 0x00 bytes followed by 0x01. 274 for (; offset + 2 < size; ++offset) { 275 if (data[offset + 2] == 0x01 && data[offset] == 0x00 276 && data[offset + 1] == 0x00) { 277 break; 278 } 279 } 280 if (offset + 2 >= size) { 281 *_data = &data[offset]; 282 *_size = 2; 283 return -EAGAIN; 284 } 285 offset += 3; 286 287 size_t startOffset = offset; 288 289 for (;;) { 290 while (offset < size && data[offset] != 0x01) { 291 ++offset; 292 } 293 294 if (offset == size) { 295 if (startCodeFollows) { 296 offset = size + 2; 297 break; 298 } 299 300 return -EAGAIN; 301 } 302 303 if (data[offset - 1] == 0x00 && data[offset - 2] == 0x00) { 304 break; 305 } 306 307 ++offset; 308 } 309 310 size_t endOffset = offset - 2; 311 while (endOffset > startOffset + 1 && data[endOffset - 1] == 0x00) { 312 --endOffset; 313 } 314 315 *nalStart = &data[startOffset]; 316 *nalSize = endOffset - startOffset; 317 318 if (offset + 2 < size) { 319 *_data = &data[offset - 2]; 320 *_size = size - offset + 2; 321 } else { 322 *_data = NULL; 323 *_size = 0; 324 } 325 326 return OK; 327} 328 329static sp<ABuffer> FindNAL(const uint8_t *data, size_t size, unsigned nalType) { 330 const uint8_t *nalStart; 331 size_t nalSize; 332 while (getNextNALUnit(&data, &size, &nalStart, &nalSize, true) == OK) { 333 if ((nalStart[0] & 0x1f) == nalType) { 334 sp<ABuffer> buffer = new ABuffer(nalSize); 335 memcpy(buffer->data(), nalStart, nalSize); 336 return buffer; 337 } 338 } 339 340 return NULL; 341} 342 343const char *AVCProfileToString(uint8_t profile) { 344 switch (profile) { 345 case kAVCProfileBaseline: 346 return "Baseline"; 347 case kAVCProfileMain: 348 return "Main"; 349 case kAVCProfileExtended: 350 return "Extended"; 351 case kAVCProfileHigh: 352 return "High"; 353 case kAVCProfileHigh10: 354 return "High 10"; 355 case kAVCProfileHigh422: 356 return "High 422"; 357 case kAVCProfileHigh444: 358 return "High 444"; 359 case kAVCProfileCAVLC444Intra: 360 return "CAVLC 444 Intra"; 361 default: return "Unknown"; 362 } 363} 364 365sp<MetaData> MakeAVCCodecSpecificData(const sp<ABuffer> &accessUnit) { 366 const uint8_t *data = accessUnit->data(); 367 size_t size = accessUnit->size(); 368 369 sp<ABuffer> seqParamSet = FindNAL(data, size, 7); 370 if (seqParamSet == NULL) { 371 return NULL; 372 } 373 374 int32_t width, height; 375 int32_t sarWidth, sarHeight; 376 FindAVCDimensions( 377 seqParamSet, &width, &height, &sarWidth, &sarHeight); 378 379 sp<ABuffer> picParamSet = FindNAL(data, size, 8); 380 CHECK(picParamSet != NULL); 381 382 size_t csdSize = 383 1 + 3 + 1 + 1 384 + 2 * 1 + seqParamSet->size() 385 + 1 + 2 * 1 + picParamSet->size(); 386 387 sp<ABuffer> csd = new ABuffer(csdSize); 388 uint8_t *out = csd->data(); 389 390 *out++ = 0x01; // configurationVersion 391 memcpy(out, seqParamSet->data() + 1, 3); // profile/level... 392 393 uint8_t profile = out[0]; 394 uint8_t level = out[2]; 395 396 out += 3; 397 *out++ = (0x3f << 2) | 1; // lengthSize == 2 bytes 398 *out++ = 0xe0 | 1; 399 400 *out++ = seqParamSet->size() >> 8; 401 *out++ = seqParamSet->size() & 0xff; 402 memcpy(out, seqParamSet->data(), seqParamSet->size()); 403 out += seqParamSet->size(); 404 405 *out++ = 1; 406 407 *out++ = picParamSet->size() >> 8; 408 *out++ = picParamSet->size() & 0xff; 409 memcpy(out, picParamSet->data(), picParamSet->size()); 410 411#if 0 412 ALOGI("AVC seq param set"); 413 hexdump(seqParamSet->data(), seqParamSet->size()); 414#endif 415 416 sp<MetaData> meta = new MetaData; 417 meta->setCString(kKeyMIMEType, MEDIA_MIMETYPE_VIDEO_AVC); 418 419 meta->setData(kKeyAVCC, kTypeAVCC, csd->data(), csd->size()); 420 meta->setInt32(kKeyWidth, width); 421 meta->setInt32(kKeyHeight, height); 422 423 if (sarWidth > 1 || sarHeight > 1) { 424 // We treat 0:0 (unspecified) as 1:1. 425 426 meta->setInt32(kKeySARWidth, sarWidth); 427 meta->setInt32(kKeySARHeight, sarHeight); 428 429 ALOGI("found AVC codec config (%d x %d, %s-profile level %d.%d) " 430 "SAR %d : %d", 431 width, 432 height, 433 AVCProfileToString(profile), 434 level / 10, 435 level % 10, 436 sarWidth, 437 sarHeight); 438 } else { 439 ALOGI("found AVC codec config (%d x %d, %s-profile level %d.%d)", 440 width, 441 height, 442 AVCProfileToString(profile), 443 level / 10, 444 level % 10); 445 } 446 447 return meta; 448} 449 450bool IsIDR(const sp<ABuffer> &buffer) { 451 const uint8_t *data = buffer->data(); 452 size_t size = buffer->size(); 453 454 bool foundIDR = false; 455 456 const uint8_t *nalStart; 457 size_t nalSize; 458 while (getNextNALUnit(&data, &size, &nalStart, &nalSize, true) == OK) { 459 CHECK_GT(nalSize, 0u); 460 461 unsigned nalType = nalStart[0] & 0x1f; 462 463 if (nalType == 5) { 464 foundIDR = true; 465 break; 466 } 467 } 468 469 return foundIDR; 470} 471 472bool IsAVCReferenceFrame(const sp<ABuffer> &accessUnit) { 473 const uint8_t *data = accessUnit->data(); 474 size_t size = accessUnit->size(); 475 476 const uint8_t *nalStart; 477 size_t nalSize; 478 while (getNextNALUnit(&data, &size, &nalStart, &nalSize, true) == OK) { 479 CHECK_GT(nalSize, 0u); 480 481 unsigned nalType = nalStart[0] & 0x1f; 482 483 if (nalType == 5) { 484 return true; 485 } else if (nalType == 1) { 486 unsigned nal_ref_idc = (nalStart[0] >> 5) & 3; 487 return nal_ref_idc != 0; 488 } 489 } 490 491 return true; 492} 493 494sp<MetaData> MakeAACCodecSpecificData( 495 unsigned profile, unsigned sampling_freq_index, 496 unsigned channel_configuration) { 497 sp<MetaData> meta = new MetaData; 498 meta->setCString(kKeyMIMEType, MEDIA_MIMETYPE_AUDIO_AAC); 499 500 CHECK_LE(sampling_freq_index, 11u); 501 static const int32_t kSamplingFreq[] = { 502 96000, 88200, 64000, 48000, 44100, 32000, 24000, 22050, 503 16000, 12000, 11025, 8000 504 }; 505 meta->setInt32(kKeySampleRate, kSamplingFreq[sampling_freq_index]); 506 meta->setInt32(kKeyChannelCount, channel_configuration); 507 508 static const uint8_t kStaticESDS[] = { 509 0x03, 22, 510 0x00, 0x00, // ES_ID 511 0x00, // streamDependenceFlag, URL_Flag, OCRstreamFlag 512 513 0x04, 17, 514 0x40, // Audio ISO/IEC 14496-3 515 0x00, 0x00, 0x00, 0x00, 516 0x00, 0x00, 0x00, 0x00, 517 0x00, 0x00, 0x00, 0x00, 518 519 0x05, 2, 520 // AudioSpecificInfo follows 521 522 // oooo offf fccc c000 523 // o - audioObjectType 524 // f - samplingFreqIndex 525 // c - channelConfig 526 }; 527 sp<ABuffer> csd = new ABuffer(sizeof(kStaticESDS) + 2); 528 memcpy(csd->data(), kStaticESDS, sizeof(kStaticESDS)); 529 530 csd->data()[sizeof(kStaticESDS)] = 531 ((profile + 1) << 3) | (sampling_freq_index >> 1); 532 533 csd->data()[sizeof(kStaticESDS) + 1] = 534 ((sampling_freq_index << 7) & 0x80) | (channel_configuration << 3); 535 536 meta->setData(kKeyESDS, 0, csd->data(), csd->size()); 537 538 return meta; 539} 540 541bool ExtractDimensionsFromVOLHeader( 542 const uint8_t *data, size_t size, int32_t *width, int32_t *height) { 543 ABitReader br(&data[4], size - 4); 544 br.skipBits(1); // random_accessible_vol 545 unsigned video_object_type_indication = br.getBits(8); 546 547 CHECK_NE(video_object_type_indication, 548 0x21u /* Fine Granularity Scalable */); 549 550 unsigned video_object_layer_verid __unused; 551 unsigned video_object_layer_priority __unused; 552 if (br.getBits(1)) { 553 video_object_layer_verid = br.getBits(4); 554 video_object_layer_priority = br.getBits(3); 555 } 556 unsigned aspect_ratio_info = br.getBits(4); 557 if (aspect_ratio_info == 0x0f /* extended PAR */) { 558 br.skipBits(8); // par_width 559 br.skipBits(8); // par_height 560 } 561 if (br.getBits(1)) { // vol_control_parameters 562 br.skipBits(2); // chroma_format 563 br.skipBits(1); // low_delay 564 if (br.getBits(1)) { // vbv_parameters 565 br.skipBits(15); // first_half_bit_rate 566 CHECK(br.getBits(1)); // marker_bit 567 br.skipBits(15); // latter_half_bit_rate 568 CHECK(br.getBits(1)); // marker_bit 569 br.skipBits(15); // first_half_vbv_buffer_size 570 CHECK(br.getBits(1)); // marker_bit 571 br.skipBits(3); // latter_half_vbv_buffer_size 572 br.skipBits(11); // first_half_vbv_occupancy 573 CHECK(br.getBits(1)); // marker_bit 574 br.skipBits(15); // latter_half_vbv_occupancy 575 CHECK(br.getBits(1)); // marker_bit 576 } 577 } 578 unsigned video_object_layer_shape = br.getBits(2); 579 CHECK_EQ(video_object_layer_shape, 0x00u /* rectangular */); 580 581 CHECK(br.getBits(1)); // marker_bit 582 unsigned vop_time_increment_resolution = br.getBits(16); 583 CHECK(br.getBits(1)); // marker_bit 584 585 if (br.getBits(1)) { // fixed_vop_rate 586 // range [0..vop_time_increment_resolution) 587 588 // vop_time_increment_resolution 589 // 2 => 0..1, 1 bit 590 // 3 => 0..2, 2 bits 591 // 4 => 0..3, 2 bits 592 // 5 => 0..4, 3 bits 593 // ... 594 595 CHECK_GT(vop_time_increment_resolution, 0u); 596 --vop_time_increment_resolution; 597 598 unsigned numBits = 0; 599 while (vop_time_increment_resolution > 0) { 600 ++numBits; 601 vop_time_increment_resolution >>= 1; 602 } 603 604 br.skipBits(numBits); // fixed_vop_time_increment 605 } 606 607 CHECK(br.getBits(1)); // marker_bit 608 unsigned video_object_layer_width = br.getBits(13); 609 CHECK(br.getBits(1)); // marker_bit 610 unsigned video_object_layer_height = br.getBits(13); 611 CHECK(br.getBits(1)); // marker_bit 612 613 unsigned interlaced __unused = br.getBits(1); 614 615 *width = video_object_layer_width; 616 *height = video_object_layer_height; 617 618 return true; 619} 620 621bool GetMPEGAudioFrameSize( 622 uint32_t header, size_t *frame_size, 623 int *out_sampling_rate, int *out_channels, 624 int *out_bitrate, int *out_num_samples) { 625 *frame_size = 0; 626 627 if (out_sampling_rate) { 628 *out_sampling_rate = 0; 629 } 630 631 if (out_channels) { 632 *out_channels = 0; 633 } 634 635 if (out_bitrate) { 636 *out_bitrate = 0; 637 } 638 639 if (out_num_samples) { 640 *out_num_samples = 1152; 641 } 642 643 if ((header & 0xffe00000) != 0xffe00000) { 644 return false; 645 } 646 647 unsigned version = (header >> 19) & 3; 648 649 if (version == 0x01) { 650 return false; 651 } 652 653 unsigned layer = (header >> 17) & 3; 654 655 if (layer == 0x00) { 656 return false; 657 } 658 659 unsigned protection __unused = (header >> 16) & 1; 660 661 unsigned bitrate_index = (header >> 12) & 0x0f; 662 663 if (bitrate_index == 0 || bitrate_index == 0x0f) { 664 // Disallow "free" bitrate. 665 return false; 666 } 667 668 unsigned sampling_rate_index = (header >> 10) & 3; 669 670 if (sampling_rate_index == 3) { 671 return false; 672 } 673 674 static const int kSamplingRateV1[] = { 44100, 48000, 32000 }; 675 int sampling_rate = kSamplingRateV1[sampling_rate_index]; 676 if (version == 2 /* V2 */) { 677 sampling_rate /= 2; 678 } else if (version == 0 /* V2.5 */) { 679 sampling_rate /= 4; 680 } 681 682 unsigned padding = (header >> 9) & 1; 683 684 if (layer == 3) { 685 // layer I 686 687 static const int kBitrateV1[] = { 688 32, 64, 96, 128, 160, 192, 224, 256, 689 288, 320, 352, 384, 416, 448 690 }; 691 692 static const int kBitrateV2[] = { 693 32, 48, 56, 64, 80, 96, 112, 128, 694 144, 160, 176, 192, 224, 256 695 }; 696 697 int bitrate = 698 (version == 3 /* V1 */) 699 ? kBitrateV1[bitrate_index - 1] 700 : kBitrateV2[bitrate_index - 1]; 701 702 if (out_bitrate) { 703 *out_bitrate = bitrate; 704 } 705 706 *frame_size = (12000 * bitrate / sampling_rate + padding) * 4; 707 708 if (out_num_samples) { 709 *out_num_samples = 384; 710 } 711 } else { 712 // layer II or III 713 714 static const int kBitrateV1L2[] = { 715 32, 48, 56, 64, 80, 96, 112, 128, 716 160, 192, 224, 256, 320, 384 717 }; 718 719 static const int kBitrateV1L3[] = { 720 32, 40, 48, 56, 64, 80, 96, 112, 721 128, 160, 192, 224, 256, 320 722 }; 723 724 static const int kBitrateV2[] = { 725 8, 16, 24, 32, 40, 48, 56, 64, 726 80, 96, 112, 128, 144, 160 727 }; 728 729 int bitrate; 730 if (version == 3 /* V1 */) { 731 bitrate = (layer == 2 /* L2 */) 732 ? kBitrateV1L2[bitrate_index - 1] 733 : kBitrateV1L3[bitrate_index - 1]; 734 735 if (out_num_samples) { 736 *out_num_samples = 1152; 737 } 738 } else { 739 // V2 (or 2.5) 740 741 bitrate = kBitrateV2[bitrate_index - 1]; 742 if (out_num_samples) { 743 *out_num_samples = (layer == 1 /* L3 */) ? 576 : 1152; 744 } 745 } 746 747 if (out_bitrate) { 748 *out_bitrate = bitrate; 749 } 750 751 if (version == 3 /* V1 */) { 752 *frame_size = 144000 * bitrate / sampling_rate + padding; 753 } else { 754 // V2 or V2.5 755 size_t tmp = (layer == 1 /* L3 */) ? 72000 : 144000; 756 *frame_size = tmp * bitrate / sampling_rate + padding; 757 } 758 } 759 760 if (out_sampling_rate) { 761 *out_sampling_rate = sampling_rate; 762 } 763 764 if (out_channels) { 765 int channel_mode = (header >> 6) & 3; 766 767 *out_channels = (channel_mode == 3) ? 1 : 2; 768 } 769 770 return true; 771} 772 773} // namespace android 774 775