| /* |
| * 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 <algorithm> |
| #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/bitstream_reader.h" |
| #include "rtc_base/checks.h" |
| #include "rtc_base/logging.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) \ |
| do { \ |
| if (!(x)) { \ |
| RTC_LOG_F(LS_ERROR) << " (line:" << __LINE__ << ") FAILED: " #x; \ |
| return false; \ |
| } \ |
| } while (0) |
| |
| uint8_t CopyUInt8(BitstreamReader& source, rtc::BitBufferWriter& destination) { |
| uint8_t tmp = source.Read<uint8_t>(); |
| if (!destination.WriteUInt8(tmp)) { |
| source.Invalidate(); |
| } |
| return tmp; |
| } |
| |
| uint32_t CopyExpGolomb(BitstreamReader& source, |
| rtc::BitBufferWriter& destination) { |
| uint32_t tmp = source.ReadExponentialGolomb(); |
| if (!destination.WriteExponentialGolomb(tmp)) { |
| source.Invalidate(); |
| } |
| return tmp; |
| } |
| |
| uint32_t CopyBits(int bits, |
| BitstreamReader& source, |
| rtc::BitBufferWriter& destination) { |
| RTC_DCHECK_GT(bits, 0); |
| RTC_DCHECK_LE(bits, 32); |
| uint64_t tmp = source.ReadBits(bits); |
| if (!destination.WriteBits(tmp, bits)) { |
| source.Invalidate(); |
| } |
| return tmp; |
| } |
| |
| bool CopyAndRewriteVui(const SpsParser::SpsState& sps, |
| BitstreamReader& source, |
| rtc::BitBufferWriter& destination, |
| const webrtc::ColorSpace* color_space, |
| SpsVuiRewriter::ParseResult& out_vui_rewritten); |
| |
| void CopyHrdParameters(BitstreamReader& 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( |
| BitstreamReader& source, |
| rtc::BitBufferWriter& destination, |
| const ColorSpace* color_space, |
| SpsVuiRewriter::ParseResult& out_vui_rewritten); |
| bool CopyRemainingBits(BitstreamReader& 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( |
| rtc::ArrayView<const uint8_t> buffer, |
| std::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); |
| BitstreamReader source_buffer(rbsp_buffer); |
| std::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 BitBufferWriter |
| // to write with. |
| rtc::Buffer out_buffer(buffer.size() + kMaxVuiSpsIncrease); |
| rtc::BitBufferWriter sps_writer(out_buffer.data(), out_buffer.size()); |
| |
| // Check how far the SpsParser has read, and copy that data in bulk. |
| RTC_DCHECK(source_buffer.Ok()); |
| size_t total_bit_offset = |
| rbsp_buffer.size() * 8 - source_buffer.RemainingBitCount(); |
| size_t byte_offset = total_bit_offset / 8; |
| size_t bit_offset = total_bit_offset % 8; |
| 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 <= buffer.size() + kMaxVuiSpsIncrease); |
| RTC_CHECK(destination != nullptr); |
| |
| out_buffer.SetSize(byte_offset); |
| |
| // Write updates SPS to destination with added RBSP |
| H264::WriteRbsp(out_buffer, destination); |
| |
| return ParseResult::kVuiRewritten; |
| } |
| |
| SpsVuiRewriter::ParseResult SpsVuiRewriter::ParseAndRewriteSps( |
| rtc::ArrayView<const uint8_t> buffer, |
| std::optional<SpsParser::SpsState>* sps, |
| const webrtc::ColorSpace* color_space, |
| rtc::Buffer* destination, |
| Direction direction) { |
| ParseResult result = |
| ParseAndRewriteSps(buffer, sps, color_space, destination); |
| UpdateStats(result, direction); |
| return result; |
| } |
| |
| rtc::Buffer SpsVuiRewriter::ParseOutgoingBitstreamAndRewrite( |
| rtc::ArrayView<const uint8_t> buffer, |
| const webrtc::ColorSpace* color_space) { |
| std::vector<H264::NaluIndex> nalus = H264::FindNaluIndices(buffer); |
| |
| // Allocate some extra space for potentially adding a missing VUI. |
| rtc::Buffer output_buffer(/*size=*/0, /*capacity=*/buffer.size() + |
| nalus.size() * kMaxVuiSpsIncrease); |
| |
| for (const H264::NaluIndex& nalu_index : nalus) { |
| // Copy NAL unit start code. |
| rtc::ArrayView<const uint8_t> start_code = buffer.subview( |
| nalu_index.start_offset, |
| nalu_index.payload_start_offset - nalu_index.start_offset); |
| rtc::ArrayView<const uint8_t> nalu = buffer.subview( |
| nalu_index.payload_start_offset, nalu_index.payload_size); |
| if (nalu.empty()) { |
| continue; |
| } |
| if (H264::ParseNaluType(nalu[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). |
| std::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[0]); |
| |
| ParseResult result = |
| ParseAndRewriteSps(nalu.subview(H264::kNaluTypeSize), &sps, |
| color_space, &output_nalu, Direction::kOutgoing); |
| if (result == ParseResult::kVuiRewritten) { |
| output_buffer.AppendData(start_code); |
| output_buffer.AppendData(output_nalu.data(), output_nalu.size()); |
| continue; |
| } |
| } else if (H264::ParseNaluType(nalu[0]) == H264::NaluType::kAud) { |
| // Skip the access unit delimiter copy. |
| continue; |
| } |
| |
| // vui wasn't rewritten and it is not aud, copy the nal unit as is. |
| output_buffer.AppendData(start_code); |
| output_buffer.AppendData(nalu); |
| } |
| return output_buffer; |
| } |
| |
| namespace { |
| bool CopyAndRewriteVui(const SpsParser::SpsState& sps, |
| BitstreamReader& source, |
| rtc::BitBufferWriter& destination, |
| const webrtc::ColorSpace* color_space, |
| SpsVuiRewriter::ParseResult& out_vui_rewritten) { |
| 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) |
| uint32_t aspect_ratio_info_present_flag = CopyBits(1, source, destination); |
| if (aspect_ratio_info_present_flag) { |
| // aspect_ratio_idc: u(8) |
| uint8_t aspect_ratio_idc = CopyUInt8(source, destination); |
| if (aspect_ratio_idc == 255u) { // Extended_SAR |
| // sar_width/sar_height: u(16) each. |
| CopyBits(32, source, destination); |
| } |
| } |
| // overscan_info_present_flag: u(1) |
| uint32_t overscan_info_present_flag = CopyBits(1, source, destination); |
| if (overscan_info_present_flag) { |
| // overscan_appropriate_flag: u(1) |
| CopyBits(1, source, destination); |
| } |
| |
| CopyOrRewriteVideoSignalTypeInfo(source, destination, color_space, |
| out_vui_rewritten); |
| |
| // chroma_loc_info_present_flag: u(1) |
| uint32_t chroma_loc_info_present_flag = CopyBits(1, source, destination); |
| if (chroma_loc_info_present_flag == 1) { |
| // chroma_sample_loc_type_(top|bottom)_field: ue(v) each. |
| CopyExpGolomb(source, destination); |
| CopyExpGolomb(source, destination); |
| } |
| // timing_info_present_flag: u(1) |
| uint32_t timing_info_present_flag = CopyBits(1, source, destination); |
| if (timing_info_present_flag == 1) { |
| // num_units_in_tick, time_scale: u(32) each |
| CopyBits(32, source, destination); |
| CopyBits(32, source, destination); |
| // fixed_frame_rate_flag: u(1) |
| CopyBits(1, source, destination); |
| } |
| // nal_hrd_parameters_present_flag: u(1) |
| uint32_t nal_hrd_parameters_present_flag = CopyBits(1, source, destination); |
| if (nal_hrd_parameters_present_flag == 1) { |
| CopyHrdParameters(source, destination); |
| } |
| // vcl_hrd_parameters_present_flag: u(1) |
| uint32_t vcl_hrd_parameters_present_flag = CopyBits(1, source, destination); |
| if (vcl_hrd_parameters_present_flag == 1) { |
| CopyHrdParameters(source, destination); |
| } |
| if (nal_hrd_parameters_present_flag == 1 || |
| vcl_hrd_parameters_present_flag == 1) { |
| // low_delay_hrd_flag: u(1) |
| CopyBits(1, source, destination); |
| } |
| // pic_struct_present_flag: u(1) |
| CopyBits(1, source, destination); |
| |
| // bitstream_restriction_flag: u(1) |
| uint32_t bitstream_restriction_flag = source.ReadBit(); |
| 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) |
| CopyBits(1, source, destination); |
| // max_bytes_per_pic_denom: ue(v) |
| CopyExpGolomb(source, destination); |
| // max_bits_per_mb_denom: ue(v) |
| CopyExpGolomb(source, destination); |
| // log2_max_mv_length_horizontal: ue(v) |
| CopyExpGolomb(source, destination); |
| // log2_max_mv_length_vertical: ue(v) |
| CopyExpGolomb(source, destination); |
| // ********* 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 = source.ReadExponentialGolomb(); |
| uint32_t max_dec_frame_buffering = source.ReadExponentialGolomb(); |
| 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 source.Ok(); |
| } |
| |
| // Copies a VUI HRD parameters segment. |
| void CopyHrdParameters(BitstreamReader& source, |
| rtc::BitBufferWriter& destination) { |
| // cbp_cnt_minus1: ue(v) |
| uint32_t cbp_cnt_minus1 = CopyExpGolomb(source, destination); |
| // bit_rate_scale and cbp_size_scale: u(4) each |
| CopyBits(8, source, destination); |
| for (size_t i = 0; source.Ok() && i <= cbp_cnt_minus1; ++i) { |
| // bit_rate_value_minus1 and cbp_size_value_minus1: ue(v) each |
| CopyExpGolomb(source, destination); |
| CopyExpGolomb(source, destination); |
| // cbr_flag: u(1) |
| CopyBits(1, source, destination); |
| } |
| // initial_cbp_removal_delay_length_minus1: u(5) |
| // cbp_removal_delay_length_minus1: u(5) |
| // dbp_output_delay_length_minus1: u(5) |
| // time_offset_length: u(5) |
| CopyBits(5 * 4, source, destination); |
| } |
| |
| // 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( |
| BitstreamReader& source, |
| rtc::BitBufferWriter& destination, |
| const ColorSpace* color_space, |
| SpsVuiRewriter::ParseResult& out_vui_rewritten) { |
| // Read. |
| 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 |
| uint32_t video_signal_type_present_flag = source.ReadBit(); |
| if (video_signal_type_present_flag) { |
| video_format = source.ReadBits(3); |
| video_full_range_flag = source.ReadBit(); |
| colour_description_present_flag = source.ReadBit(); |
| if (colour_description_present_flag) { |
| colour_primaries = source.Read<uint8_t>(); |
| transfer_characteristics = source.Read<uint8_t>(); |
| matrix_coefficients = source.Read<uint8_t>(); |
| } |
| } |
| RETURN_FALSE_ON_FAIL(source.Ok()); |
| |
| // 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(BitstreamReader& source, |
| rtc::BitBufferWriter& destination) { |
| // Try to get at least the destination aligned. |
| if (source.RemainingBitCount() > 0 && source.RemainingBitCount() % 8 != 0) { |
| size_t misaligned_bits = source.RemainingBitCount() % 8; |
| CopyBits(misaligned_bits, source, destination); |
| } |
| while (source.RemainingBitCount() > 0) { |
| int count = std::min(32, source.RemainingBitCount()); |
| CopyBits(count, source, destination); |
| } |
| // TODO(noahric): The last byte could be all zeroes now, which we should just |
| // strip. |
| return source.Ok(); |
| } |
| |
| } // namespace |
| |
| } // namespace webrtc |
