aosp12/external/webrtc/common_video/h264/sps_vui_rewriter.cc

627 lines
24 KiB
C++

/*
* Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
*
* Use of this source code is governed by a BSD-style license
* that can be found in the LICENSE file in the root of the source
* tree. An additional intellectual property rights grant can be found
* in the file PATENTS. All contributing project authors may
* be found in the AUTHORS file in the root of the source tree.
*
*/
#include "common_video/h264/sps_vui_rewriter.h"
#include <string.h>
#include <cstdint>
#include <vector>
#include "api/video/color_space.h"
#include "common_video/h264/h264_common.h"
#include "common_video/h264/sps_parser.h"
#include "rtc_base/bit_buffer.h"
#include "rtc_base/checks.h"
#include "rtc_base/logging.h"
#include "rtc_base/numerics/safe_minmax.h"
#include "system_wrappers/include/metrics.h"
namespace webrtc {
namespace {
// The maximum expected growth from adding a VUI to the SPS. It's actually
// closer to 24 or so, but better safe than sorry.
const size_t kMaxVuiSpsIncrease = 64;
const char* kSpsValidHistogramName = "WebRTC.Video.H264.SpsValid";
enum SpsValidEvent {
kReceivedSpsVuiOk = 1,
kReceivedSpsRewritten = 2,
kReceivedSpsParseFailure = 3,
kSentSpsPocOk = 4,
kSentSpsVuiOk = 5,
kSentSpsRewritten = 6,
kSentSpsParseFailure = 7,
kSpsRewrittenMax = 8
};
#define RETURN_FALSE_ON_FAIL(x) \
if (!(x)) { \
RTC_LOG_F(LS_ERROR) << " (line:" << __LINE__ << ") FAILED: " #x; \
return false; \
}
#define COPY_UINT8(src, dest, tmp) \
do { \
RETURN_FALSE_ON_FAIL((src)->ReadUInt8(&tmp)); \
if (dest) \
RETURN_FALSE_ON_FAIL((dest)->WriteUInt8(tmp)); \
} while (0)
#define COPY_EXP_GOLOMB(src, dest, tmp) \
do { \
RETURN_FALSE_ON_FAIL((src)->ReadExponentialGolomb(&tmp)); \
if (dest) \
RETURN_FALSE_ON_FAIL((dest)->WriteExponentialGolomb(tmp)); \
} while (0)
#define COPY_BITS(src, dest, tmp, bits) \
do { \
RETURN_FALSE_ON_FAIL((src)->ReadBits(&tmp, bits)); \
if (dest) \
RETURN_FALSE_ON_FAIL((dest)->WriteBits(tmp, bits)); \
} while (0)
bool CopyAndRewriteVui(const SpsParser::SpsState& sps,
rtc::BitBuffer* source,
rtc::BitBufferWriter* destination,
const webrtc::ColorSpace* color_space,
SpsVuiRewriter::ParseResult* out_vui_rewritten);
bool CopyHrdParameters(rtc::BitBuffer* source,
rtc::BitBufferWriter* destination);
bool AddBitstreamRestriction(rtc::BitBufferWriter* destination,
uint32_t max_num_ref_frames);
bool IsDefaultColorSpace(const ColorSpace& color_space);
bool AddVideoSignalTypeInfo(rtc::BitBufferWriter* destination,
const ColorSpace& color_space);
bool CopyOrRewriteVideoSignalTypeInfo(
rtc::BitBuffer* source,
rtc::BitBufferWriter* destination,
const ColorSpace* color_space,
SpsVuiRewriter::ParseResult* out_vui_rewritten);
bool CopyRemainingBits(rtc::BitBuffer* source,
rtc::BitBufferWriter* destination);
} // namespace
void SpsVuiRewriter::UpdateStats(ParseResult result, Direction direction) {
switch (result) {
case SpsVuiRewriter::ParseResult::kVuiRewritten:
RTC_HISTOGRAM_ENUMERATION(
kSpsValidHistogramName,
direction == SpsVuiRewriter::Direction::kIncoming
? SpsValidEvent::kReceivedSpsRewritten
: SpsValidEvent::kSentSpsRewritten,
SpsValidEvent::kSpsRewrittenMax);
break;
case SpsVuiRewriter::ParseResult::kVuiOk:
RTC_HISTOGRAM_ENUMERATION(
kSpsValidHistogramName,
direction == SpsVuiRewriter::Direction::kIncoming
? SpsValidEvent::kReceivedSpsVuiOk
: SpsValidEvent::kSentSpsVuiOk,
SpsValidEvent::kSpsRewrittenMax);
break;
case SpsVuiRewriter::ParseResult::kFailure:
RTC_HISTOGRAM_ENUMERATION(
kSpsValidHistogramName,
direction == SpsVuiRewriter::Direction::kIncoming
? SpsValidEvent::kReceivedSpsParseFailure
: SpsValidEvent::kSentSpsParseFailure,
SpsValidEvent::kSpsRewrittenMax);
break;
}
}
SpsVuiRewriter::ParseResult SpsVuiRewriter::ParseAndRewriteSps(
const uint8_t* buffer,
size_t length,
absl::optional<SpsParser::SpsState>* sps,
const webrtc::ColorSpace* color_space,
rtc::Buffer* destination) {
// Create temporary RBSP decoded buffer of the payload (exlcuding the
// leading nalu type header byte (the SpsParser uses only the payload).
std::vector<uint8_t> rbsp_buffer = H264::ParseRbsp(buffer, length);
rtc::BitBuffer source_buffer(rbsp_buffer.data(), rbsp_buffer.size());
absl::optional<SpsParser::SpsState> sps_state =
SpsParser::ParseSpsUpToVui(&source_buffer);
if (!sps_state)
return ParseResult::kFailure;
*sps = sps_state;
// We're going to completely muck up alignment, so we need a BitBuffer to
// write with.
rtc::Buffer out_buffer(length + kMaxVuiSpsIncrease);
rtc::BitBufferWriter sps_writer(out_buffer.data(), out_buffer.size());
// Check how far the SpsParser has read, and copy that data in bulk.
size_t byte_offset;
size_t bit_offset;
source_buffer.GetCurrentOffset(&byte_offset, &bit_offset);
memcpy(out_buffer.data(), rbsp_buffer.data(),
byte_offset + (bit_offset > 0 ? 1 : 0)); // OK to copy the last bits.
// SpsParser will have read the vui_params_present flag, which we want to
// modify, so back off a bit;
if (bit_offset == 0) {
--byte_offset;
bit_offset = 7;
} else {
--bit_offset;
}
sps_writer.Seek(byte_offset, bit_offset);
ParseResult vui_updated;
if (!CopyAndRewriteVui(*sps_state, &source_buffer, &sps_writer, color_space,
&vui_updated)) {
RTC_LOG(LS_ERROR) << "Failed to parse/copy SPS VUI.";
return ParseResult::kFailure;
}
if (vui_updated == ParseResult::kVuiOk) {
// No update necessary after all, just return.
return vui_updated;
}
if (!CopyRemainingBits(&source_buffer, &sps_writer)) {
RTC_LOG(LS_ERROR) << "Failed to parse/copy SPS VUI.";
return ParseResult::kFailure;
}
// Pad up to next byte with zero bits.
sps_writer.GetCurrentOffset(&byte_offset, &bit_offset);
if (bit_offset > 0) {
sps_writer.WriteBits(0, 8 - bit_offset);
++byte_offset;
bit_offset = 0;
}
RTC_DCHECK(byte_offset <= length + kMaxVuiSpsIncrease);
RTC_CHECK(destination != nullptr);
out_buffer.SetSize(byte_offset);
// Write updates SPS to destination with added RBSP
H264::WriteRbsp(out_buffer.data(), out_buffer.size(), destination);
return ParseResult::kVuiRewritten;
}
SpsVuiRewriter::ParseResult SpsVuiRewriter::ParseAndRewriteSps(
const uint8_t* buffer,
size_t length,
absl::optional<SpsParser::SpsState>* sps,
const webrtc::ColorSpace* color_space,
rtc::Buffer* destination,
Direction direction) {
ParseResult result =
ParseAndRewriteSps(buffer, length, sps, color_space, destination);
UpdateStats(result, direction);
return result;
}
void SpsVuiRewriter::ParseOutgoingBitstreamAndRewriteSps(
rtc::ArrayView<const uint8_t> buffer,
size_t num_nalus,
const size_t* nalu_offsets,
const size_t* nalu_lengths,
const webrtc::ColorSpace* color_space,
rtc::Buffer* output_buffer,
size_t* output_nalu_offsets,
size_t* output_nalu_lengths) {
// Allocate some extra space for potentially adding a missing VUI.
output_buffer->EnsureCapacity(buffer.size() + num_nalus * kMaxVuiSpsIncrease);
const uint8_t* prev_nalu_ptr = buffer.data();
size_t prev_nalu_length = 0;
for (size_t i = 0; i < num_nalus; ++i) {
const uint8_t* nalu_ptr = buffer.data() + nalu_offsets[i];
const size_t nalu_length = nalu_lengths[i];
// Copy NAL unit start code.
const uint8_t* start_code_ptr = prev_nalu_ptr + prev_nalu_length;
const size_t start_code_length =
(nalu_ptr - prev_nalu_ptr) - prev_nalu_length;
output_buffer->AppendData(start_code_ptr, start_code_length);
bool updated_sps = false;
if (H264::ParseNaluType(nalu_ptr[0]) == H264::NaluType::kSps) {
// Check if stream uses picture order count type 0, and if so rewrite it
// to enable faster decoding. Streams in that format incur additional
// delay because it allows decode order to differ from render order.
// The mechanism used is to rewrite (edit or add) the SPS's VUI to contain
// restrictions on the maximum number of reordered pictures. This reduces
// latency significantly, though it still adds about a frame of latency to
// decoding.
// Note that we do this rewriting both here (send side, in order to
// protect legacy receive clients) in RtpDepacketizerH264::ParseSingleNalu
// (receive side, in orderer to protect us from unknown or legacy send
// clients).
absl::optional<SpsParser::SpsState> sps;
rtc::Buffer output_nalu;
// Add the type header to the output buffer first, so that the rewriter
// can append modified payload on top of that.
output_nalu.AppendData(nalu_ptr[0]);
ParseResult result = ParseAndRewriteSps(
nalu_ptr + H264::kNaluTypeSize, nalu_length - H264::kNaluTypeSize,
&sps, color_space, &output_nalu, Direction::kOutgoing);
if (result == ParseResult::kVuiRewritten) {
updated_sps = true;
output_nalu_offsets[i] = output_buffer->size();
output_nalu_lengths[i] = output_nalu.size();
output_buffer->AppendData(output_nalu.data(), output_nalu.size());
}
}
if (!updated_sps) {
output_nalu_offsets[i] = output_buffer->size();
output_nalu_lengths[i] = nalu_length;
output_buffer->AppendData(nalu_ptr, nalu_length);
}
prev_nalu_ptr = nalu_ptr;
prev_nalu_length = nalu_length;
}
}
namespace {
bool CopyAndRewriteVui(const SpsParser::SpsState& sps,
rtc::BitBuffer* source,
rtc::BitBufferWriter* destination,
const webrtc::ColorSpace* color_space,
SpsVuiRewriter::ParseResult* out_vui_rewritten) {
uint32_t golomb_tmp;
uint32_t bits_tmp;
*out_vui_rewritten = SpsVuiRewriter::ParseResult::kVuiOk;
//
// vui_parameters_present_flag: u(1)
//
RETURN_FALSE_ON_FAIL(destination->WriteBits(1, 1));
// ********* IMPORTANT! **********
// Now we're at the VUI, so we want to (1) add it if it isn't present, and
// (2) rewrite frame reordering values so no reordering is allowed.
if (!sps.vui_params_present) {
// Write a simple VUI with the parameters we want and 0 for all other flags.
// aspect_ratio_info_present_flag, overscan_info_present_flag. Both u(1).
RETURN_FALSE_ON_FAIL(destination->WriteBits(0, 2));
uint32_t video_signal_type_present_flag =
(color_space && !IsDefaultColorSpace(*color_space)) ? 1 : 0;
RETURN_FALSE_ON_FAIL(
destination->WriteBits(video_signal_type_present_flag, 1));
if (video_signal_type_present_flag) {
RETURN_FALSE_ON_FAIL(AddVideoSignalTypeInfo(destination, *color_space));
}
// chroma_loc_info_present_flag, timing_info_present_flag,
// nal_hrd_parameters_present_flag, vcl_hrd_parameters_present_flag,
// pic_struct_present_flag, All u(1)
RETURN_FALSE_ON_FAIL(destination->WriteBits(0, 5));
// bitstream_restriction_flag: u(1)
RETURN_FALSE_ON_FAIL(destination->WriteBits(1, 1));
RETURN_FALSE_ON_FAIL(
AddBitstreamRestriction(destination, sps.max_num_ref_frames));
*out_vui_rewritten = SpsVuiRewriter::ParseResult::kVuiRewritten;
} else {
// Parse out the full VUI.
// aspect_ratio_info_present_flag: u(1)
COPY_BITS(source, destination, bits_tmp, 1);
if (bits_tmp == 1) {
// aspect_ratio_idc: u(8)
COPY_BITS(source, destination, bits_tmp, 8);
if (bits_tmp == 255u) { // Extended_SAR
// sar_width/sar_height: u(16) each.
COPY_BITS(source, destination, bits_tmp, 32);
}
}
// overscan_info_present_flag: u(1)
COPY_BITS(source, destination, bits_tmp, 1);
if (bits_tmp == 1) {
// overscan_appropriate_flag: u(1)
COPY_BITS(source, destination, bits_tmp, 1);
}
CopyOrRewriteVideoSignalTypeInfo(source, destination, color_space,
out_vui_rewritten);
// chroma_loc_info_present_flag: u(1)
COPY_BITS(source, destination, bits_tmp, 1);
if (bits_tmp == 1) {
// chroma_sample_loc_type_(top|bottom)_field: ue(v) each.
COPY_EXP_GOLOMB(source, destination, golomb_tmp);
COPY_EXP_GOLOMB(source, destination, golomb_tmp);
}
// timing_info_present_flag: u(1)
COPY_BITS(source, destination, bits_tmp, 1);
if (bits_tmp == 1) {
// num_units_in_tick, time_scale: u(32) each
COPY_BITS(source, destination, bits_tmp, 32);
COPY_BITS(source, destination, bits_tmp, 32);
// fixed_frame_rate_flag: u(1)
COPY_BITS(source, destination, bits_tmp, 1);
}
// nal_hrd_parameters_present_flag: u(1)
uint32_t nal_hrd_parameters_present_flag;
COPY_BITS(source, destination, nal_hrd_parameters_present_flag, 1);
if (nal_hrd_parameters_present_flag == 1) {
RETURN_FALSE_ON_FAIL(CopyHrdParameters(source, destination));
}
// vcl_hrd_parameters_present_flag: u(1)
uint32_t vcl_hrd_parameters_present_flag;
COPY_BITS(source, destination, vcl_hrd_parameters_present_flag, 1);
if (vcl_hrd_parameters_present_flag == 1) {
RETURN_FALSE_ON_FAIL(CopyHrdParameters(source, destination));
}
if (nal_hrd_parameters_present_flag == 1 ||
vcl_hrd_parameters_present_flag == 1) {
// low_delay_hrd_flag: u(1)
COPY_BITS(source, destination, bits_tmp, 1);
}
// pic_struct_present_flag: u(1)
COPY_BITS(source, destination, bits_tmp, 1);
// bitstream_restriction_flag: u(1)
uint32_t bitstream_restriction_flag;
RETURN_FALSE_ON_FAIL(source->ReadBits(&bitstream_restriction_flag, 1));
RETURN_FALSE_ON_FAIL(destination->WriteBits(1, 1));
if (bitstream_restriction_flag == 0) {
// We're adding one from scratch.
RETURN_FALSE_ON_FAIL(
AddBitstreamRestriction(destination, sps.max_num_ref_frames));
*out_vui_rewritten = SpsVuiRewriter::ParseResult::kVuiRewritten;
} else {
// We're replacing.
// motion_vectors_over_pic_boundaries_flag: u(1)
COPY_BITS(source, destination, bits_tmp, 1);
// max_bytes_per_pic_denom: ue(v)
COPY_EXP_GOLOMB(source, destination, golomb_tmp);
// max_bits_per_mb_denom: ue(v)
COPY_EXP_GOLOMB(source, destination, golomb_tmp);
// log2_max_mv_length_horizontal: ue(v)
COPY_EXP_GOLOMB(source, destination, golomb_tmp);
// log2_max_mv_length_vertical: ue(v)
COPY_EXP_GOLOMB(source, destination, golomb_tmp);
// ********* IMPORTANT! **********
// The next two are the ones we need to set to low numbers:
// max_num_reorder_frames: ue(v)
// max_dec_frame_buffering: ue(v)
// However, if they are already set to no greater than the numbers we
// want, then we don't need to be rewriting.
uint32_t max_num_reorder_frames, max_dec_frame_buffering;
RETURN_FALSE_ON_FAIL(
source->ReadExponentialGolomb(&max_num_reorder_frames));
RETURN_FALSE_ON_FAIL(
source->ReadExponentialGolomb(&max_dec_frame_buffering));
RETURN_FALSE_ON_FAIL(destination->WriteExponentialGolomb(0));
RETURN_FALSE_ON_FAIL(
destination->WriteExponentialGolomb(sps.max_num_ref_frames));
if (max_num_reorder_frames != 0 ||
max_dec_frame_buffering > sps.max_num_ref_frames) {
*out_vui_rewritten = SpsVuiRewriter::ParseResult::kVuiRewritten;
}
}
}
return true;
}
// Copies a VUI HRD parameters segment.
bool CopyHrdParameters(rtc::BitBuffer* source,
rtc::BitBufferWriter* destination) {
uint32_t golomb_tmp;
uint32_t bits_tmp;
// cbp_cnt_minus1: ue(v)
uint32_t cbp_cnt_minus1;
COPY_EXP_GOLOMB(source, destination, cbp_cnt_minus1);
// bit_rate_scale and cbp_size_scale: u(4) each
COPY_BITS(source, destination, bits_tmp, 8);
for (size_t i = 0; i <= cbp_cnt_minus1; ++i) {
// bit_rate_value_minus1 and cbp_size_value_minus1: ue(v) each
COPY_EXP_GOLOMB(source, destination, golomb_tmp);
COPY_EXP_GOLOMB(source, destination, golomb_tmp);
// cbr_flag: u(1)
COPY_BITS(source, destination, bits_tmp, 1);
}
// initial_cbp_removal_delay_length_minus1: u(5)
COPY_BITS(source, destination, bits_tmp, 5);
// cbp_removal_delay_length_minus1: u(5)
COPY_BITS(source, destination, bits_tmp, 5);
// dbp_output_delay_length_minus1: u(5)
COPY_BITS(source, destination, bits_tmp, 5);
// time_offset_length: u(5)
COPY_BITS(source, destination, bits_tmp, 5);
return true;
}
// These functions are similar to webrtc::H264SpsParser::Parse, and based on the
// same version of the H.264 standard. You can find it here:
// http://www.itu.int/rec/T-REC-H.264
// Adds a bitstream restriction VUI segment.
bool AddBitstreamRestriction(rtc::BitBufferWriter* destination,
uint32_t max_num_ref_frames) {
// motion_vectors_over_pic_boundaries_flag: u(1)
// Default is 1 when not present.
RETURN_FALSE_ON_FAIL(destination->WriteBits(1, 1));
// max_bytes_per_pic_denom: ue(v)
// Default is 2 when not present.
RETURN_FALSE_ON_FAIL(destination->WriteExponentialGolomb(2));
// max_bits_per_mb_denom: ue(v)
// Default is 1 when not present.
RETURN_FALSE_ON_FAIL(destination->WriteExponentialGolomb(1));
// log2_max_mv_length_horizontal: ue(v)
// log2_max_mv_length_vertical: ue(v)
// Both default to 16 when not present.
RETURN_FALSE_ON_FAIL(destination->WriteExponentialGolomb(16));
RETURN_FALSE_ON_FAIL(destination->WriteExponentialGolomb(16));
// ********* IMPORTANT! **********
// max_num_reorder_frames: ue(v)
RETURN_FALSE_ON_FAIL(destination->WriteExponentialGolomb(0));
// max_dec_frame_buffering: ue(v)
RETURN_FALSE_ON_FAIL(destination->WriteExponentialGolomb(max_num_ref_frames));
return true;
}
bool IsDefaultColorSpace(const ColorSpace& color_space) {
return color_space.range() != ColorSpace::RangeID::kFull &&
color_space.primaries() == ColorSpace::PrimaryID::kUnspecified &&
color_space.transfer() == ColorSpace::TransferID::kUnspecified &&
color_space.matrix() == ColorSpace::MatrixID::kUnspecified;
}
bool AddVideoSignalTypeInfo(rtc::BitBufferWriter* destination,
const ColorSpace& color_space) {
// video_format: u(3).
RETURN_FALSE_ON_FAIL(destination->WriteBits(5, 3)); // 5 = Unspecified
// video_full_range_flag: u(1)
RETURN_FALSE_ON_FAIL(destination->WriteBits(
color_space.range() == ColorSpace::RangeID::kFull ? 1 : 0, 1));
// colour_description_present_flag: u(1)
RETURN_FALSE_ON_FAIL(destination->WriteBits(1, 1));
// colour_primaries: u(8)
RETURN_FALSE_ON_FAIL(
destination->WriteUInt8(static_cast<uint8_t>(color_space.primaries())));
// transfer_characteristics: u(8)
RETURN_FALSE_ON_FAIL(
destination->WriteUInt8(static_cast<uint8_t>(color_space.transfer())));
// matrix_coefficients: u(8)
RETURN_FALSE_ON_FAIL(
destination->WriteUInt8(static_cast<uint8_t>(color_space.matrix())));
return true;
}
bool CopyOrRewriteVideoSignalTypeInfo(
rtc::BitBuffer* source,
rtc::BitBufferWriter* destination,
const ColorSpace* color_space,
SpsVuiRewriter::ParseResult* out_vui_rewritten) {
// Read.
uint32_t video_signal_type_present_flag;
uint32_t video_format = 5; // H264 default: unspecified
uint32_t video_full_range_flag = 0; // H264 default: limited
uint32_t colour_description_present_flag = 0;
uint8_t colour_primaries = 3; // H264 default: unspecified
uint8_t transfer_characteristics = 3; // H264 default: unspecified
uint8_t matrix_coefficients = 3; // H264 default: unspecified
RETURN_FALSE_ON_FAIL(source->ReadBits(&video_signal_type_present_flag, 1));
if (video_signal_type_present_flag) {
RETURN_FALSE_ON_FAIL(source->ReadBits(&video_format, 3));
RETURN_FALSE_ON_FAIL(source->ReadBits(&video_full_range_flag, 1));
RETURN_FALSE_ON_FAIL(source->ReadBits(&colour_description_present_flag, 1));
if (colour_description_present_flag) {
RETURN_FALSE_ON_FAIL(source->ReadUInt8(&colour_primaries));
RETURN_FALSE_ON_FAIL(source->ReadUInt8(&transfer_characteristics));
RETURN_FALSE_ON_FAIL(source->ReadUInt8(&matrix_coefficients));
}
}
// Update.
uint32_t video_signal_type_present_flag_override =
video_signal_type_present_flag;
uint32_t video_format_override = video_format;
uint32_t video_full_range_flag_override = video_full_range_flag;
uint32_t colour_description_present_flag_override =
colour_description_present_flag;
uint8_t colour_primaries_override = colour_primaries;
uint8_t transfer_characteristics_override = transfer_characteristics;
uint8_t matrix_coefficients_override = matrix_coefficients;
if (color_space) {
if (IsDefaultColorSpace(*color_space)) {
video_signal_type_present_flag_override = 0;
} else {
video_signal_type_present_flag_override = 1;
video_format_override = 5; // unspecified
if (color_space->range() == ColorSpace::RangeID::kFull) {
video_full_range_flag_override = 1;
} else {
// ColorSpace::RangeID::kInvalid and kDerived are treated as limited.
video_full_range_flag_override = 0;
}
colour_description_present_flag_override =
color_space->primaries() != ColorSpace::PrimaryID::kUnspecified ||
color_space->transfer() != ColorSpace::TransferID::kUnspecified ||
color_space->matrix() != ColorSpace::MatrixID::kUnspecified;
colour_primaries_override =
static_cast<uint8_t>(color_space->primaries());
transfer_characteristics_override =
static_cast<uint8_t>(color_space->transfer());
matrix_coefficients_override =
static_cast<uint8_t>(color_space->matrix());
}
}
// Write.
RETURN_FALSE_ON_FAIL(
destination->WriteBits(video_signal_type_present_flag_override, 1));
if (video_signal_type_present_flag_override) {
RETURN_FALSE_ON_FAIL(destination->WriteBits(video_format_override, 3));
RETURN_FALSE_ON_FAIL(
destination->WriteBits(video_full_range_flag_override, 1));
RETURN_FALSE_ON_FAIL(
destination->WriteBits(colour_description_present_flag_override, 1));
if (colour_description_present_flag_override) {
RETURN_FALSE_ON_FAIL(destination->WriteUInt8(colour_primaries_override));
RETURN_FALSE_ON_FAIL(
destination->WriteUInt8(transfer_characteristics_override));
RETURN_FALSE_ON_FAIL(
destination->WriteUInt8(matrix_coefficients_override));
}
}
if (video_signal_type_present_flag_override !=
video_signal_type_present_flag ||
video_format_override != video_format ||
video_full_range_flag_override != video_full_range_flag ||
colour_description_present_flag_override !=
colour_description_present_flag ||
colour_primaries_override != colour_primaries ||
transfer_characteristics_override != transfer_characteristics ||
matrix_coefficients_override != matrix_coefficients) {
*out_vui_rewritten = SpsVuiRewriter::ParseResult::kVuiRewritten;
}
return true;
}
bool CopyRemainingBits(rtc::BitBuffer* source,
rtc::BitBufferWriter* destination) {
uint32_t bits_tmp;
// Try to get at least the destination aligned.
if (source->RemainingBitCount() > 0 && source->RemainingBitCount() % 8 != 0) {
size_t misaligned_bits = source->RemainingBitCount() % 8;
COPY_BITS(source, destination, bits_tmp, misaligned_bits);
}
while (source->RemainingBitCount() > 0) {
auto count = rtc::SafeMin<size_t>(32u, source->RemainingBitCount());
COPY_BITS(source, destination, bits_tmp, count);
}
// TODO(noahric): The last byte could be all zeroes now, which we should just
// strip.
return true;
}
} // namespace
} // namespace webrtc