785 lines
23 KiB
C++
785 lines
23 KiB
C++
/*
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* Copyright (C) 2010 The Android Open Source Project
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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//#define LOG_NDEBUG 0
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#define LOG_TAG "avc_utils"
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#include <utils/Log.h>
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#include <media/stagefright/foundation/ABitReader.h>
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#include <media/stagefright/foundation/ADebug.h>
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#include <media/stagefright/foundation/avc_utils.h>
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#include <media/stagefright/foundation/hexdump.h>
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#include <media/stagefright/MediaDefs.h>
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#include <media/stagefright/MediaErrors.h>
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#include <media/stagefright/MetaData.h>
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#include <utils/misc.h>
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namespace android {
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unsigned parseUE(ABitReader *br) {
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unsigned numZeroes = 0;
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while (br->getBits(1) == 0) {
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++numZeroes;
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}
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unsigned x = br->getBits(numZeroes);
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return x + (1u << numZeroes) - 1;
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}
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unsigned parseUEWithFallback(ABitReader *br, unsigned fallback) {
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unsigned numZeroes = 0;
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while (br->getBitsWithFallback(1, 1) == 0) {
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++numZeroes;
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}
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uint32_t x;
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if (numZeroes < 32) {
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if (br->getBitsGraceful(numZeroes, &x)) {
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return x + (1u << numZeroes) - 1;
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} else {
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return fallback;
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}
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} else {
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br->skipBits(numZeroes);
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return fallback;
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}
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}
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signed parseSE(ABitReader *br) {
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unsigned codeNum = parseUE(br);
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return (codeNum & 1) ? (codeNum + 1) / 2 : -signed(codeNum / 2);
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}
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signed parseSEWithFallback(ABitReader *br, signed fallback) {
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// NOTE: parseUE cannot normally return ~0 as the max supported value is 0xFFFE
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unsigned codeNum = parseUEWithFallback(br, ~0U);
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if (codeNum == ~0U) {
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return fallback;
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}
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return (codeNum & 1) ? (codeNum + 1) / 2 : -signed(codeNum / 2);
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}
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static void skipScalingList(ABitReader *br, size_t sizeOfScalingList) {
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size_t lastScale = 8;
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size_t nextScale = 8;
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for (size_t j = 0; j < sizeOfScalingList; ++j) {
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if (nextScale != 0) {
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signed delta_scale = parseSE(br);
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// ISO_IEC_14496-10_201402-ITU, 7.4.2.1.1.1, The value of delta_scale
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// shall be in the range of −128 to +127, inclusive.
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if (delta_scale < -128) {
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ALOGW("delta_scale (%d) is below range, capped to -128", delta_scale);
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delta_scale = -128;
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} else if (delta_scale > 127) {
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ALOGW("delta_scale (%d) is above range, capped to 127", delta_scale);
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delta_scale = 127;
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}
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nextScale = (lastScale + (delta_scale + 256)) % 256;
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}
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lastScale = (nextScale == 0) ? lastScale : nextScale;
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}
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}
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// Determine video dimensions from the sequence parameterset.
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void FindAVCDimensions(
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const sp<ABuffer> &seqParamSet,
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int32_t *width, int32_t *height,
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int32_t *sarWidth, int32_t *sarHeight) {
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ABitReader br(seqParamSet->data() + 1, seqParamSet->size() - 1);
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unsigned profile_idc = br.getBits(8);
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br.skipBits(16);
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parseUE(&br); // seq_parameter_set_id
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unsigned chroma_format_idc = 1; // 4:2:0 chroma format
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if (profile_idc == 100 || profile_idc == 110
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|| profile_idc == 122 || profile_idc == 244
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|| profile_idc == 44 || profile_idc == 83 || profile_idc == 86) {
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chroma_format_idc = parseUE(&br);
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if (chroma_format_idc == 3) {
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br.skipBits(1); // residual_colour_transform_flag
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}
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parseUE(&br); // bit_depth_luma_minus8
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parseUE(&br); // bit_depth_chroma_minus8
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br.skipBits(1); // qpprime_y_zero_transform_bypass_flag
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if (br.getBits(1)) { // seq_scaling_matrix_present_flag
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for (size_t i = 0; i < 8; ++i) {
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if (br.getBits(1)) { // seq_scaling_list_present_flag[i]
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// WARNING: the code below has not ever been exercised...
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// need a real-world example.
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if (i < 6) {
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// ScalingList4x4[i],16,...
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skipScalingList(&br, 16);
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} else {
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// ScalingList8x8[i-6],64,...
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skipScalingList(&br, 64);
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}
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}
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}
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}
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}
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parseUE(&br); // log2_max_frame_num_minus4
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unsigned pic_order_cnt_type = parseUE(&br);
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if (pic_order_cnt_type == 0) {
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parseUE(&br); // log2_max_pic_order_cnt_lsb_minus4
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} else if (pic_order_cnt_type == 1) {
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// offset_for_non_ref_pic, offset_for_top_to_bottom_field and
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// offset_for_ref_frame are technically se(v), but since we are
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// just skipping over them the midpoint does not matter.
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br.getBits(1); // delta_pic_order_always_zero_flag
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parseUE(&br); // offset_for_non_ref_pic
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parseUE(&br); // offset_for_top_to_bottom_field
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unsigned num_ref_frames_in_pic_order_cnt_cycle = parseUE(&br);
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for (unsigned i = 0; i < num_ref_frames_in_pic_order_cnt_cycle; ++i) {
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parseUE(&br); // offset_for_ref_frame
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}
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}
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parseUE(&br); // num_ref_frames
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br.getBits(1); // gaps_in_frame_num_value_allowed_flag
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unsigned pic_width_in_mbs_minus1 = parseUE(&br);
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unsigned pic_height_in_map_units_minus1 = parseUE(&br);
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unsigned frame_mbs_only_flag = br.getBits(1);
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// *width = pic_width_in_mbs_minus1 * 16 + 16;
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if (__builtin_mul_overflow(pic_width_in_mbs_minus1, 16, &pic_width_in_mbs_minus1) ||
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__builtin_add_overflow(pic_width_in_mbs_minus1, 16, width)) {
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*width = 0;
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}
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// *height = (2 - frame_mbs_only_flag) * (pic_height_in_map_units_minus1 * 16 + 16);
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if (__builtin_mul_overflow(
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pic_height_in_map_units_minus1, 16, &pic_height_in_map_units_minus1) ||
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__builtin_add_overflow(
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pic_height_in_map_units_minus1, 16, &pic_height_in_map_units_minus1) ||
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__builtin_mul_overflow(
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pic_height_in_map_units_minus1, (2 - frame_mbs_only_flag), height)) {
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*height = 0;
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}
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if (!frame_mbs_only_flag) {
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br.getBits(1); // mb_adaptive_frame_field_flag
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}
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br.getBits(1); // direct_8x8_inference_flag
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if (br.getBits(1)) { // frame_cropping_flag
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unsigned frame_crop_left_offset = parseUE(&br);
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unsigned frame_crop_right_offset = parseUE(&br);
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unsigned frame_crop_top_offset = parseUE(&br);
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unsigned frame_crop_bottom_offset = parseUE(&br);
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unsigned cropUnitX, cropUnitY;
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if (chroma_format_idc == 0 /* monochrome */) {
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cropUnitX = 1;
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cropUnitY = 2 - frame_mbs_only_flag;
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} else {
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unsigned subWidthC = (chroma_format_idc == 3) ? 1 : 2;
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unsigned subHeightC = (chroma_format_idc == 1) ? 2 : 1;
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cropUnitX = subWidthC;
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cropUnitY = subHeightC * (2 - frame_mbs_only_flag);
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}
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ALOGV("frame_crop = (%u, %u, %u, %u), cropUnitX = %u, cropUnitY = %u",
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frame_crop_left_offset, frame_crop_right_offset,
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frame_crop_top_offset, frame_crop_bottom_offset,
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cropUnitX, cropUnitY);
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// *width -= (frame_crop_left_offset + frame_crop_right_offset) * cropUnitX;
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if(__builtin_add_overflow(
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frame_crop_left_offset, frame_crop_right_offset, &frame_crop_left_offset) ||
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__builtin_mul_overflow(frame_crop_left_offset, cropUnitX, &frame_crop_left_offset) ||
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__builtin_sub_overflow(*width, frame_crop_left_offset, width) ||
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*width < 0) {
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*width = 0;
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}
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//*height -= (frame_crop_top_offset + frame_crop_bottom_offset) * cropUnitY;
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if(__builtin_add_overflow(
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frame_crop_top_offset, frame_crop_bottom_offset, &frame_crop_top_offset) ||
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__builtin_mul_overflow(frame_crop_top_offset, cropUnitY, &frame_crop_top_offset) ||
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__builtin_sub_overflow(*height, frame_crop_top_offset, height) ||
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*height < 0) {
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*height = 0;
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}
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}
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if (sarWidth != NULL) {
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*sarWidth = 0;
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}
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if (sarHeight != NULL) {
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*sarHeight = 0;
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}
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if (br.getBits(1)) { // vui_parameters_present_flag
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unsigned sar_width = 0, sar_height = 0;
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if (br.getBits(1)) { // aspect_ratio_info_present_flag
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unsigned aspect_ratio_idc = br.getBits(8);
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if (aspect_ratio_idc == 255 /* extendedSAR */) {
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sar_width = br.getBits(16);
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sar_height = br.getBits(16);
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} else {
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static const struct { unsigned width, height; } kFixedSARs[] = {
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{ 0, 0 }, // Invalid
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{ 1, 1 },
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{ 12, 11 },
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{ 10, 11 },
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{ 16, 11 },
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{ 40, 33 },
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{ 24, 11 },
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{ 20, 11 },
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{ 32, 11 },
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{ 80, 33 },
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{ 18, 11 },
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{ 15, 11 },
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{ 64, 33 },
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{ 160, 99 },
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{ 4, 3 },
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{ 3, 2 },
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{ 2, 1 },
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};
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if (aspect_ratio_idc > 0 && aspect_ratio_idc < NELEM(kFixedSARs)) {
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sar_width = kFixedSARs[aspect_ratio_idc].width;
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sar_height = kFixedSARs[aspect_ratio_idc].height;
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}
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}
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}
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ALOGV("sample aspect ratio = %u : %u", sar_width, sar_height);
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if (sarWidth != NULL) {
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*sarWidth = sar_width;
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}
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if (sarHeight != NULL) {
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*sarHeight = sar_height;
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}
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}
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}
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status_t getNextNALUnit(
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const uint8_t **_data, size_t *_size,
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const uint8_t **nalStart, size_t *nalSize,
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bool startCodeFollows) {
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const uint8_t *data = *_data;
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size_t size = *_size;
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*nalStart = NULL;
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*nalSize = 0;
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if (size < 3) {
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return -EAGAIN;
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}
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size_t offset = 0;
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// A valid startcode consists of at least two 0x00 bytes followed by 0x01.
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for (; offset + 2 < size; ++offset) {
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if (data[offset + 2] == 0x01 && data[offset] == 0x00
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&& data[offset + 1] == 0x00) {
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break;
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}
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}
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if (offset + 2 >= size) {
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*_data = &data[offset];
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*_size = 2;
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return -EAGAIN;
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}
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offset += 3;
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size_t startOffset = offset;
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for (;;) {
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while (offset < size && data[offset] != 0x01) {
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++offset;
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}
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if (offset == size) {
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if (startCodeFollows) {
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offset = size + 2;
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break;
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}
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return -EAGAIN;
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}
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if (data[offset - 1] == 0x00 && data[offset - 2] == 0x00) {
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break;
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}
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++offset;
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}
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size_t endOffset = offset - 2;
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while (endOffset > startOffset + 1 && data[endOffset - 1] == 0x00) {
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--endOffset;
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}
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*nalStart = &data[startOffset];
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*nalSize = endOffset - startOffset;
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if (offset + 2 < size) {
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*_data = &data[offset - 2];
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*_size = size - offset + 2;
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} else {
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*_data = NULL;
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*_size = 0;
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}
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return OK;
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}
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static sp<ABuffer> FindNAL(const uint8_t *data, size_t size, unsigned nalType) {
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const uint8_t *nalStart;
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size_t nalSize;
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while (getNextNALUnit(&data, &size, &nalStart, &nalSize, true) == OK) {
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if (nalSize > 0 && (nalStart[0] & 0x1f) == nalType) {
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sp<ABuffer> buffer = new ABuffer(nalSize);
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memcpy(buffer->data(), nalStart, nalSize);
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return buffer;
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}
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}
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return NULL;
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}
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const char *AVCProfileToString(uint8_t profile) {
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switch (profile) {
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case kAVCProfileBaseline:
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return "Baseline";
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case kAVCProfileMain:
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return "Main";
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case kAVCProfileExtended:
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return "Extended";
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case kAVCProfileHigh:
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return "High";
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case kAVCProfileHigh10:
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return "High 10";
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case kAVCProfileHigh422:
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return "High 422";
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case kAVCProfileHigh444:
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return "High 444";
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case kAVCProfileCAVLC444Intra:
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return "CAVLC 444 Intra";
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default: return "Unknown";
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}
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}
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sp<ABuffer> MakeAVCCodecSpecificData(
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const sp<ABuffer> &accessUnit, int32_t *width, int32_t *height,
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int32_t *sarWidth, int32_t *sarHeight) {
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const uint8_t *data = accessUnit->data();
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size_t size = accessUnit->size();
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sp<ABuffer> seqParamSet = FindNAL(data, size, 7);
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if (seqParamSet == NULL) {
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return NULL;
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}
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FindAVCDimensions(
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seqParamSet, width, height, sarWidth, sarHeight);
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sp<ABuffer> picParamSet = FindNAL(data, size, 8);
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CHECK(picParamSet != NULL);
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size_t csdSize =
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1 + 3 + 1 + 1
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+ 2 * 1 + seqParamSet->size()
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+ 1 + 2 * 1 + picParamSet->size();
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sp<ABuffer> csd = new ABuffer(csdSize);
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uint8_t *out = csd->data();
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*out++ = 0x01; // configurationVersion
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memcpy(out, seqParamSet->data() + 1, 3); // profile/level...
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uint8_t profile = out[0];
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uint8_t level = out[2];
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out += 3;
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*out++ = (0x3f << 2) | 1; // lengthSize == 2 bytes
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*out++ = 0xe0 | 1;
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*out++ = seqParamSet->size() >> 8;
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*out++ = seqParamSet->size() & 0xff;
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memcpy(out, seqParamSet->data(), seqParamSet->size());
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out += seqParamSet->size();
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*out++ = 1;
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*out++ = picParamSet->size() >> 8;
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*out++ = picParamSet->size() & 0xff;
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memcpy(out, picParamSet->data(), picParamSet->size());
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#if 0
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ALOGI("AVC seq param set");
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hexdump(seqParamSet->data(), seqParamSet->size());
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#endif
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if (sarWidth != nullptr && sarHeight != nullptr) {
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if ((*sarWidth > 0 && *sarHeight > 0) && (*sarWidth != 1 || *sarHeight != 1)) {
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ALOGI("found AVC codec config (%d x %d, %s-profile level %d.%d) "
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"SAR %d : %d",
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*width,
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*height,
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AVCProfileToString(profile),
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level / 10,
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level % 10,
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*sarWidth,
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*sarHeight);
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} else {
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// We treat *:0 and 0:* (unspecified) as 1:1.
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*sarWidth = 0;
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*sarHeight = 0;
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ALOGI("found AVC codec config (%d x %d, %s-profile level %d.%d)",
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*width,
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*height,
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AVCProfileToString(profile),
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level / 10,
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level % 10);
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}
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}
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return csd;
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}
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bool IsIDR(const uint8_t *data, size_t size) {
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// const uint8_t *data = buffer->data();
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// size_t size = buffer->size();
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bool foundIDR = false;
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const uint8_t *nalStart;
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size_t nalSize;
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while (getNextNALUnit(&data, &size, &nalStart, &nalSize, true) == OK) {
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if (nalSize == 0u) {
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ALOGW("skipping empty nal unit from potentially malformed bitstream");
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continue;
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}
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unsigned nalType = nalStart[0] & 0x1f;
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if (nalType == 5) {
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foundIDR = true;
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break;
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}
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}
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return foundIDR;
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}
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bool IsAVCReferenceFrame(const sp<ABuffer> &accessUnit) {
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const uint8_t *data = accessUnit->data();
|
||
size_t size = accessUnit->size();
|
||
if (data == NULL) {
|
||
ALOGE("IsAVCReferenceFrame: called on NULL data (%p, %zu)", accessUnit.get(), size);
|
||
return false;
|
||
}
|
||
|
||
const uint8_t *nalStart;
|
||
size_t nalSize;
|
||
while (getNextNALUnit(&data, &size, &nalStart, &nalSize, true) == OK) {
|
||
if (nalSize == 0) {
|
||
ALOGE("IsAVCReferenceFrame: invalid nalSize: 0 (%p, %zu)", accessUnit.get(), size);
|
||
return false;
|
||
}
|
||
|
||
unsigned nalType = nalStart[0] & 0x1f;
|
||
|
||
if (nalType == 5) {
|
||
return true;
|
||
} else if (nalType == 1) {
|
||
unsigned nal_ref_idc = (nalStart[0] >> 5) & 3;
|
||
return nal_ref_idc != 0;
|
||
}
|
||
}
|
||
|
||
return true;
|
||
}
|
||
|
||
uint32_t FindAVCLayerId(const uint8_t *data, size_t size) {
|
||
CHECK(data != NULL);
|
||
|
||
const unsigned kSvcNalType = 0xE;
|
||
const unsigned kSvcNalSearchRange = 32;
|
||
// SVC NAL
|
||
// |---0 1110|1--- ----|---- ----|iii- ---|
|
||
// ^ ^
|
||
// NAL-type = 0xE layer-Id
|
||
//
|
||
// layer_id 0 is for base layer, while 1, 2, ... are enhancement layers.
|
||
// Layer n uses reference frames from layer 0, 1, ..., n-1.
|
||
|
||
uint32_t layerId = 0;
|
||
sp<ABuffer> svcNAL = FindNAL(
|
||
data, size > kSvcNalSearchRange ? kSvcNalSearchRange : size, kSvcNalType);
|
||
if (svcNAL != NULL && svcNAL->size() >= 4) {
|
||
layerId = (*(svcNAL->data() + 3) >> 5) & 0x7;
|
||
}
|
||
return layerId;
|
||
}
|
||
|
||
bool ExtractDimensionsFromVOLHeader(
|
||
const uint8_t *data, size_t size, int32_t *width, int32_t *height) {
|
||
ABitReader br(&data[4], size - 4);
|
||
br.skipBits(1); // random_accessible_vol
|
||
unsigned video_object_type_indication = br.getBits(8);
|
||
|
||
CHECK_NE(video_object_type_indication,
|
||
0x21u /* Fine Granularity Scalable */);
|
||
|
||
if (br.getBits(1)) {
|
||
br.skipBits(4); //video_object_layer_verid
|
||
br.skipBits(3); //video_object_layer_priority
|
||
}
|
||
unsigned aspect_ratio_info = br.getBits(4);
|
||
if (aspect_ratio_info == 0x0f /* extended PAR */) {
|
||
br.skipBits(8); // par_width
|
||
br.skipBits(8); // par_height
|
||
}
|
||
if (br.getBits(1)) { // vol_control_parameters
|
||
br.skipBits(2); // chroma_format
|
||
br.skipBits(1); // low_delay
|
||
if (br.getBits(1)) { // vbv_parameters
|
||
br.skipBits(15); // first_half_bit_rate
|
||
CHECK(br.getBits(1)); // marker_bit
|
||
br.skipBits(15); // latter_half_bit_rate
|
||
CHECK(br.getBits(1)); // marker_bit
|
||
br.skipBits(15); // first_half_vbv_buffer_size
|
||
CHECK(br.getBits(1)); // marker_bit
|
||
br.skipBits(3); // latter_half_vbv_buffer_size
|
||
br.skipBits(11); // first_half_vbv_occupancy
|
||
CHECK(br.getBits(1)); // marker_bit
|
||
br.skipBits(15); // latter_half_vbv_occupancy
|
||
CHECK(br.getBits(1)); // marker_bit
|
||
}
|
||
}
|
||
unsigned video_object_layer_shape = br.getBits(2);
|
||
CHECK_EQ(video_object_layer_shape, 0x00u /* rectangular */);
|
||
|
||
CHECK(br.getBits(1)); // marker_bit
|
||
unsigned vop_time_increment_resolution = br.getBits(16);
|
||
CHECK(br.getBits(1)); // marker_bit
|
||
|
||
if (br.getBits(1)) { // fixed_vop_rate
|
||
// range [0..vop_time_increment_resolution)
|
||
|
||
// vop_time_increment_resolution
|
||
// 2 => 0..1, 1 bit
|
||
// 3 => 0..2, 2 bits
|
||
// 4 => 0..3, 2 bits
|
||
// 5 => 0..4, 3 bits
|
||
// ...
|
||
|
||
CHECK_GT(vop_time_increment_resolution, 0u);
|
||
--vop_time_increment_resolution;
|
||
|
||
unsigned numBits = 0;
|
||
while (vop_time_increment_resolution > 0) {
|
||
++numBits;
|
||
vop_time_increment_resolution >>= 1;
|
||
}
|
||
|
||
br.skipBits(numBits); // fixed_vop_time_increment
|
||
}
|
||
|
||
CHECK(br.getBits(1)); // marker_bit
|
||
unsigned video_object_layer_width = br.getBits(13);
|
||
CHECK(br.getBits(1)); // marker_bit
|
||
unsigned video_object_layer_height = br.getBits(13);
|
||
CHECK(br.getBits(1)); // marker_bit
|
||
|
||
br.skipBits(1); // interlaced
|
||
|
||
*width = video_object_layer_width;
|
||
*height = video_object_layer_height;
|
||
|
||
return true;
|
||
}
|
||
|
||
bool GetMPEGAudioFrameSize(
|
||
uint32_t header, size_t *frame_size,
|
||
int *out_sampling_rate, int *out_channels,
|
||
int *out_bitrate, int *out_num_samples) {
|
||
*frame_size = 0;
|
||
|
||
if (out_sampling_rate) {
|
||
*out_sampling_rate = 0;
|
||
}
|
||
|
||
if (out_channels) {
|
||
*out_channels = 0;
|
||
}
|
||
|
||
if (out_bitrate) {
|
||
*out_bitrate = 0;
|
||
}
|
||
|
||
if (out_num_samples) {
|
||
*out_num_samples = 1152;
|
||
}
|
||
|
||
if ((header & 0xffe00000) != 0xffe00000) {
|
||
return false;
|
||
}
|
||
|
||
unsigned version = (header >> 19) & 3;
|
||
|
||
if (version == 0x01) {
|
||
return false;
|
||
}
|
||
|
||
unsigned layer = (header >> 17) & 3;
|
||
|
||
if (layer == 0x00) {
|
||
return false;
|
||
}
|
||
|
||
// we can get protection value from (header >> 16) & 1
|
||
|
||
unsigned bitrate_index = (header >> 12) & 0x0f;
|
||
|
||
if (bitrate_index == 0 || bitrate_index == 0x0f) {
|
||
// Disallow "free" bitrate.
|
||
return false;
|
||
}
|
||
|
||
unsigned sampling_rate_index = (header >> 10) & 3;
|
||
|
||
if (sampling_rate_index == 3) {
|
||
return false;
|
||
}
|
||
|
||
static const int kSamplingRateV1[] = { 44100, 48000, 32000 };
|
||
int sampling_rate = kSamplingRateV1[sampling_rate_index];
|
||
if (version == 2 /* V2 */) {
|
||
sampling_rate /= 2;
|
||
} else if (version == 0 /* V2.5 */) {
|
||
sampling_rate /= 4;
|
||
}
|
||
|
||
unsigned padding = (header >> 9) & 1;
|
||
|
||
if (layer == 3) {
|
||
// layer I
|
||
|
||
static const int kBitrateV1[] = {
|
||
32, 64, 96, 128, 160, 192, 224, 256,
|
||
288, 320, 352, 384, 416, 448
|
||
};
|
||
|
||
static const int kBitrateV2[] = {
|
||
32, 48, 56, 64, 80, 96, 112, 128,
|
||
144, 160, 176, 192, 224, 256
|
||
};
|
||
|
||
int bitrate =
|
||
(version == 3 /* V1 */)
|
||
? kBitrateV1[bitrate_index - 1]
|
||
: kBitrateV2[bitrate_index - 1];
|
||
|
||
if (out_bitrate) {
|
||
*out_bitrate = bitrate;
|
||
}
|
||
|
||
*frame_size = (12000 * bitrate / sampling_rate + padding) * 4;
|
||
|
||
if (out_num_samples) {
|
||
*out_num_samples = 384;
|
||
}
|
||
} else {
|
||
// layer II or III
|
||
|
||
static const int kBitrateV1L2[] = {
|
||
32, 48, 56, 64, 80, 96, 112, 128,
|
||
160, 192, 224, 256, 320, 384
|
||
};
|
||
|
||
static const int kBitrateV1L3[] = {
|
||
32, 40, 48, 56, 64, 80, 96, 112,
|
||
128, 160, 192, 224, 256, 320
|
||
};
|
||
|
||
static const int kBitrateV2[] = {
|
||
8, 16, 24, 32, 40, 48, 56, 64,
|
||
80, 96, 112, 128, 144, 160
|
||
};
|
||
|
||
int bitrate;
|
||
if (version == 3 /* V1 */) {
|
||
bitrate = (layer == 2 /* L2 */)
|
||
? kBitrateV1L2[bitrate_index - 1]
|
||
: kBitrateV1L3[bitrate_index - 1];
|
||
|
||
if (out_num_samples) {
|
||
*out_num_samples = 1152;
|
||
}
|
||
} else {
|
||
// V2 (or 2.5)
|
||
|
||
bitrate = kBitrateV2[bitrate_index - 1];
|
||
if (out_num_samples) {
|
||
*out_num_samples = (layer == 1 /* L3 */) ? 576 : 1152;
|
||
}
|
||
}
|
||
|
||
if (out_bitrate) {
|
||
*out_bitrate = bitrate;
|
||
}
|
||
|
||
if (version == 3 /* V1 */) {
|
||
*frame_size = 144000 * bitrate / sampling_rate + padding;
|
||
} else {
|
||
// V2 or V2.5
|
||
size_t tmp = (layer == 1 /* L3 */) ? 72000 : 144000;
|
||
*frame_size = tmp * bitrate / sampling_rate + padding;
|
||
}
|
||
}
|
||
|
||
if (out_sampling_rate) {
|
||
*out_sampling_rate = sampling_rate;
|
||
}
|
||
|
||
if (out_channels) {
|
||
int channel_mode = (header >> 6) & 3;
|
||
|
||
*out_channels = (channel_mode == 3) ? 1 : 2;
|
||
}
|
||
|
||
return true;
|
||
}
|
||
|
||
} // namespace android
|
||
|