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/*
* 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 "modules/video_coding/h264_sps_pps_tracker.h"
#include <memory>
#include <string>
#include <utility>
#include "absl/types/variant.h"
#include "common_video/h264/h264_common.h"
#include "common_video/h264/pps_parser.h"
#include "common_video/h264/sps_parser.h"
#include "modules/video_coding/codecs/h264/include/h264_globals.h"
#include "rtc_base/checks.h"
#include "rtc_base/logging.h"
namespace webrtc {
namespace video_coding {
namespace {
const uint8_t start_code_h264[] = {0, 0, 0, 1};
} // namespace
H264SpsPpsTracker::H264SpsPpsTracker() = default;
H264SpsPpsTracker::~H264SpsPpsTracker() = default;
H264SpsPpsTracker::PpsInfo::PpsInfo() = default;
H264SpsPpsTracker::PpsInfo::PpsInfo(PpsInfo&& rhs) = default;
H264SpsPpsTracker::PpsInfo& H264SpsPpsTracker::PpsInfo::operator=(
PpsInfo&& rhs) = default;
H264SpsPpsTracker::PpsInfo::~PpsInfo() = default;
H264SpsPpsTracker::SpsInfo::SpsInfo() = default;
H264SpsPpsTracker::SpsInfo::SpsInfo(SpsInfo&& rhs) = default;
H264SpsPpsTracker::SpsInfo& H264SpsPpsTracker::SpsInfo::operator=(
SpsInfo&& rhs) = default;
H264SpsPpsTracker::SpsInfo::~SpsInfo() = default;
H264SpsPpsTracker::FixedBitstream H264SpsPpsTracker::CopyAndFixBitstream(
rtc::ArrayView<const uint8_t> bitstream,
RTPVideoHeader* video_header) {
RTC_DCHECK(video_header);
RTC_DCHECK(video_header->codec == kVideoCodecH264);
RTC_DCHECK_GT(bitstream.size(), 0);
auto& h264_header =
absl::get<RTPVideoHeaderH264>(video_header->video_type_header);
bool append_sps_pps = false;
auto sps = sps_data_.end();
auto pps = pps_data_.end();
for (const NaluInfo& nalu : h264_header.nalus) {
switch (nalu.type) {
case H264::NaluType::kSps: {
SpsInfo& sps_info = sps_data_[nalu.sps_id];
sps_info.width = video_header->width;
sps_info.height = video_header->height;
break;
}
case H264::NaluType::kPps: {
pps_data_[nalu.pps_id].sps_id = nalu.sps_id;
break;
}
case H264::NaluType::kIdr: {
// If this is the first packet of an IDR, make sure we have the required
// SPS/PPS and also calculate how much extra space we need in the buffer
// to prepend the SPS/PPS to the bitstream with start codes.
if (video_header->is_first_packet_in_frame) {
if (nalu.pps_id == -1) {
RTC_LOG(LS_WARNING) << "No PPS id in IDR nalu.";
return {kRequestKeyframe};
}
pps = pps_data_.find(nalu.pps_id);
if (pps == pps_data_.end()) {
RTC_LOG(LS_WARNING)
<< "No PPS with id << " << nalu.pps_id << " received";
return {kRequestKeyframe};
}
sps = sps_data_.find(pps->second.sps_id);
if (sps == sps_data_.end()) {
RTC_LOG(LS_WARNING)
<< "No SPS with id << " << pps->second.sps_id << " received";
return {kRequestKeyframe};
}
// Since the first packet of every keyframe should have its width and
// height set we set it here in the case of it being supplied out of
// band.
video_header->width = sps->second.width;
video_header->height = sps->second.height;
// If the SPS/PPS was supplied out of band then we will have saved
// the actual bitstream in `data`.
if (sps->second.data && pps->second.data) {
RTC_DCHECK_GT(sps->second.size, 0);
RTC_DCHECK_GT(pps->second.size, 0);
append_sps_pps = true;
}
}
break;
}
default:
break;
}
}
RTC_CHECK(!append_sps_pps ||
(sps != sps_data_.end() && pps != pps_data_.end()));
// Calculate how much space we need for the rest of the bitstream.
size_t required_size = 0;
if (append_sps_pps) {
required_size += sps->second.size + sizeof(start_code_h264);
required_size += pps->second.size + sizeof(start_code_h264);
}
if (h264_header.packetization_type == kH264StapA) {
const uint8_t* nalu_ptr = bitstream.data() + 1;
while (nalu_ptr < bitstream.data() + bitstream.size() - 1) {
required_size += sizeof(start_code_h264);
// The first two bytes describe the length of a segment.
uint16_t segment_length = nalu_ptr[0] << 8 | nalu_ptr[1];
nalu_ptr += 2;
required_size += segment_length;
nalu_ptr += segment_length;
}
} else {
if (!h264_header.nalus.empty()) {
required_size += sizeof(start_code_h264);
}
required_size += bitstream.size();
}
// Then we copy to the new buffer.
H264SpsPpsTracker::FixedBitstream fixed;
fixed.bitstream.EnsureCapacity(required_size);
if (append_sps_pps) {
// Insert SPS.
fixed.bitstream.AppendData(start_code_h264);
fixed.bitstream.AppendData(sps->second.data.get(), sps->second.size);
// Insert PPS.
fixed.bitstream.AppendData(start_code_h264);
fixed.bitstream.AppendData(pps->second.data.get(), pps->second.size);
// Update codec header to reflect the newly added SPS and PPS.
h264_header.nalus.push_back(
{.type = H264::NaluType::kSps, .sps_id = sps->first, .pps_id = -1});
h264_header.nalus.push_back({.type = H264::NaluType::kPps,
.sps_id = sps->first,
.pps_id = pps->first});
}
// Copy the rest of the bitstream and insert start codes.
if (h264_header.packetization_type == kH264StapA) {
const uint8_t* nalu_ptr = bitstream.data() + 1;
while (nalu_ptr < bitstream.data() + bitstream.size() - 1) {
fixed.bitstream.AppendData(start_code_h264);
// The first two bytes describe the length of a segment.
uint16_t segment_length = nalu_ptr[0] << 8 | nalu_ptr[1];
nalu_ptr += 2;
size_t copy_end = nalu_ptr - bitstream.data() + segment_length;
if (copy_end > bitstream.size()) {
return {kDrop};
}
fixed.bitstream.AppendData(nalu_ptr, segment_length);
nalu_ptr += segment_length;
}
} else {
if (!h264_header.nalus.empty()) {
fixed.bitstream.AppendData(start_code_h264);
}
fixed.bitstream.AppendData(bitstream.data(), bitstream.size());
}
fixed.action = kInsert;
return fixed;
}
void H264SpsPpsTracker::InsertSpsPpsNalus(const std::vector<uint8_t>& sps,
const std::vector<uint8_t>& pps) {
constexpr size_t kNaluHeaderOffset = 1;
if (sps.size() < kNaluHeaderOffset) {
RTC_LOG(LS_WARNING) << "SPS size " << sps.size() << " is smaller than "
<< kNaluHeaderOffset;
return;
}
if ((sps[0] & 0x1f) != H264::NaluType::kSps) {
RTC_LOG(LS_WARNING) << "SPS Nalu header missing";
return;
}
if (pps.size() < kNaluHeaderOffset) {
RTC_LOG(LS_WARNING) << "PPS size " << pps.size() << " is smaller than "
<< kNaluHeaderOffset;
return;
}
if ((pps[0] & 0x1f) != H264::NaluType::kPps) {
RTC_LOG(LS_WARNING) << "SPS Nalu header missing";
return;
}
absl::optional<SpsParser::SpsState> parsed_sps = SpsParser::ParseSps(
rtc::ArrayView<const uint8_t>(sps).subview(kNaluHeaderOffset));
absl::optional<PpsParser::PpsState> parsed_pps = PpsParser::ParsePps(
rtc::ArrayView<const uint8_t>(pps).subview(kNaluHeaderOffset));
if (!parsed_sps) {
RTC_LOG(LS_WARNING) << "Failed to parse SPS.";
}
if (!parsed_pps) {
RTC_LOG(LS_WARNING) << "Failed to parse PPS.";
}
if (!parsed_pps || !parsed_sps) {
return;
}
SpsInfo sps_info;
sps_info.size = sps.size();
sps_info.width = parsed_sps->width;
sps_info.height = parsed_sps->height;
uint8_t* sps_data = new uint8_t[sps_info.size];
memcpy(sps_data, sps.data(), sps_info.size);
sps_info.data.reset(sps_data);
sps_data_[parsed_sps->id] = std::move(sps_info);
PpsInfo pps_info;
pps_info.size = pps.size();
pps_info.sps_id = parsed_pps->sps_id;
uint8_t* pps_data = new uint8_t[pps_info.size];
memcpy(pps_data, pps.data(), pps_info.size);
pps_info.data.reset(pps_data);
pps_data_[parsed_pps->id] = std::move(pps_info);
RTC_LOG(LS_INFO) << "Inserted SPS id " << parsed_sps->id << " and PPS id "
<< parsed_pps->id << " (referencing SPS "
<< parsed_pps->sps_id << ")";
}
} // namespace video_coding
} // namespace webrtc