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fcebe0e1ca5c4c32211337a287af81fe0a8b9e3f
platform-external-webrtc/modules/rtp_rtcp/source/rtp_format_h264.cc
Danil Chapovalov fcebe0e1ca in RtpPacketizers separate case 'frame fits into single packet'. 
Assumption extra needed bytes for single packet needs is sum
of extra bytes for first and last packet
moved up to RTPSenderVideo from individual packetizers.
There it can be fixed.

Bug: webrtc:9868
Change-Id: I24c80ffa5c174afd3fe3e92fa86ef75560bb961e
Reviewed-on: https://webrtc-review.googlesource.com/c/105662
Commit-Queue: Danil Chapovalov <danilchap@webrtc.org>
Reviewed-by: Ilya Nikolaevskiy <ilnik@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#25160}
2018-10-15 08:46:27 +00:00

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/*
* Copyright (c) 2014 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/rtp_rtcp/source/rtp_format_h264.h"
#include <string.h>
#include <memory>
#include <utility>
#include <vector>
#include "common_video/h264/h264_common.h"
#include "common_video/h264/pps_parser.h"
#include "common_video/h264/sps_parser.h"
#include "common_video/h264/sps_vui_rewriter.h"
#include "modules/include/module_common_types.h"
#include "modules/rtp_rtcp/source/byte_io.h"
#include "modules/rtp_rtcp/source/rtp_packet_to_send.h"
#include "rtc_base/checks.h"
#include "rtc_base/logging.h"
#include "rtc_base/system/fallthrough.h"
#include "system_wrappers/include/metrics.h"
namespace webrtc {
namespace {
static const size_t kNalHeaderSize = 1;
static const size_t kFuAHeaderSize = 2;
static const size_t kLengthFieldSize = 2;
static const size_t kStapAHeaderSize = kNalHeaderSize + kLengthFieldSize;
static const char* kSpsValidHistogramName = "WebRTC.Video.H264.SpsValid";
enum SpsValidEvent {
kReceivedSpsPocOk = 0,
kReceivedSpsVuiOk = 1,
kReceivedSpsRewritten = 2,
kReceivedSpsParseFailure = 3,
kSentSpsPocOk = 4,
kSentSpsVuiOk = 5,
kSentSpsRewritten = 6,
kSentSpsParseFailure = 7,
kSpsRewrittenMax = 8
};
// Bit masks for FU (A and B) indicators.
enum NalDefs : uint8_t { kFBit = 0x80, kNriMask = 0x60, kTypeMask = 0x1F };
// Bit masks for FU (A and B) headers.
enum FuDefs : uint8_t { kSBit = 0x80, kEBit = 0x40, kRBit = 0x20 };
// TODO(pbos): Avoid parsing this here as well as inside the jitter buffer.
bool ParseStapAStartOffsets(const uint8_t* nalu_ptr,
size_t length_remaining,
std::vector<size_t>* offsets) {
size_t offset = 0;
while (length_remaining > 0) {
// Buffer doesn't contain room for additional nalu length.
if (length_remaining < sizeof(uint16_t))
return false;
uint16_t nalu_size = ByteReader<uint16_t>::ReadBigEndian(nalu_ptr);
nalu_ptr += sizeof(uint16_t);
length_remaining -= sizeof(uint16_t);
if (nalu_size > length_remaining)
return false;
nalu_ptr += nalu_size;
length_remaining -= nalu_size;
offsets->push_back(offset + kStapAHeaderSize);
offset += kLengthFieldSize + nalu_size;
}
return true;
}
} // namespace
RtpPacketizerH264::RtpPacketizerH264(
rtc::ArrayView<const uint8_t> payload,
PayloadSizeLimits limits,
H264PacketizationMode packetization_mode,
const RTPFragmentationHeader& fragmentation)
: limits_(limits), num_packets_left_(0) {
// Guard against uninitialized memory in packetization_mode.
RTC_CHECK(packetization_mode == H264PacketizationMode::NonInterleaved ||
packetization_mode == H264PacketizationMode::SingleNalUnit);
for (int i = 0; i < fragmentation.fragmentationVectorSize; ++i) {
const uint8_t* buffer =
payload.data() + fragmentation.fragmentationOffset[i];
size_t length = fragmentation.fragmentationLength[i];
bool updated_sps = false;
H264::NaluType nalu_type = H264::ParseNaluType(buffer[0]);
if (nalu_type == 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) and below in
// RtpDepacketizerH264::ParseSingleNalu (receive side, in orderer to
// protect us from unknown or legacy send clients).
absl::optional<SpsParser::SpsState> sps;
std::unique_ptr<rtc::Buffer> output_buffer(new rtc::Buffer());
// Add the type header to the output buffer first, so that the rewriter
// can append modified payload on top of that.
output_buffer->AppendData(buffer[0]);
SpsVuiRewriter::ParseResult result = SpsVuiRewriter::ParseAndRewriteSps(
buffer + H264::kNaluTypeSize, length - H264::kNaluTypeSize, &sps,
output_buffer.get());
switch (result) {
case SpsVuiRewriter::ParseResult::kVuiRewritten:
input_fragments_.push_back(
Fragment(output_buffer->data(), output_buffer->size()));
input_fragments_.rbegin()->tmp_buffer = std::move(output_buffer);
updated_sps = true;
RTC_HISTOGRAM_ENUMERATION(kSpsValidHistogramName,
SpsValidEvent::kSentSpsRewritten,
SpsValidEvent::kSpsRewrittenMax);
break;
case SpsVuiRewriter::ParseResult::kPocOk:
RTC_HISTOGRAM_ENUMERATION(kSpsValidHistogramName,
SpsValidEvent::kSentSpsPocOk,
SpsValidEvent::kSpsRewrittenMax);
break;
case SpsVuiRewriter::ParseResult::kVuiOk:
RTC_HISTOGRAM_ENUMERATION(kSpsValidHistogramName,
SpsValidEvent::kSentSpsVuiOk,
SpsValidEvent::kSpsRewrittenMax);
break;
case SpsVuiRewriter::ParseResult::kFailure:
RTC_HISTOGRAM_ENUMERATION(kSpsValidHistogramName,
SpsValidEvent::kSentSpsParseFailure,
SpsValidEvent::kSpsRewrittenMax);
break;
}
}
if (!updated_sps)
input_fragments_.push_back(Fragment(buffer, length));
}
if (!GeneratePackets(packetization_mode)) {
// If failed to generate all the packets, discard already generated
// packets in case the caller would ignore return value and still try to
// call NextPacket().
num_packets_left_ = 0;
while (!packets_.empty()) {
packets_.pop();
}
}
}
RtpPacketizerH264::~RtpPacketizerH264() = default;
RtpPacketizerH264::Fragment::~Fragment() = default;
RtpPacketizerH264::Fragment::Fragment(const uint8_t* buffer, size_t length)
: buffer(buffer), length(length) {}
RtpPacketizerH264::Fragment::Fragment(const Fragment& fragment)
: buffer(fragment.buffer), length(fragment.length) {}
size_t RtpPacketizerH264::NumPackets() const {
return num_packets_left_;
}
bool RtpPacketizerH264::GeneratePackets(
H264PacketizationMode packetization_mode) {
for (size_t i = 0; i < input_fragments_.size();) {
switch (packetization_mode) {
case H264PacketizationMode::SingleNalUnit:
if (!PacketizeSingleNalu(i))
return false;
++i;
break;
case H264PacketizationMode::NonInterleaved:
int fragment_len = input_fragments_[i].length;
int single_packet_capacity = limits_.max_payload_len;
if (input_fragments_.size() == 1)
single_packet_capacity -= limits_.single_packet_reduction_len;
else if (i == 0)
single_packet_capacity -= limits_.first_packet_reduction_len;
else if (i + 1 == input_fragments_.size())
single_packet_capacity -= limits_.last_packet_reduction_len;
if (fragment_len > single_packet_capacity) {
if (!PacketizeFuA(i))
return false;
++i;
} else {
i = PacketizeStapA(i);
}
break;
}
}
return true;
}
bool RtpPacketizerH264::PacketizeFuA(size_t fragment_index) {
// Fragment payload into packets (FU-A).
const Fragment& fragment = input_fragments_[fragment_index];
PayloadSizeLimits limits = limits_;
// Leave room for the FU-A header.
limits.max_payload_len -= kFuAHeaderSize;
// Ignore single/first/last packet reductions unless it is single/first/last
// fragment.
if (input_fragments_.size() != 1)
limits.single_packet_reduction_len = 0;
if (fragment_index != 0)
limits.first_packet_reduction_len = 0;
if (fragment_index != input_fragments_.size() - 1)
limits.last_packet_reduction_len = 0;
// Strip out the original header.
size_t payload_left = fragment.length - kNalHeaderSize;
int offset = kNalHeaderSize;
std::vector<int> payload_sizes = SplitAboutEqually(payload_left, limits);
if (payload_sizes.empty())
return false;
for (size_t i = 0; i < payload_sizes.size(); ++i) {
int packet_length = payload_sizes[i];
RTC_CHECK_GT(packet_length, 0);
packets_.push(PacketUnit(Fragment(fragment.buffer + offset, packet_length),
/*first_fragment=*/i == 0,
/*last_fragment=*/i == payload_sizes.size() - 1,
false, fragment.buffer[0]));
offset += packet_length;
payload_left -= packet_length;
}
num_packets_left_ += payload_sizes.size();
RTC_CHECK_EQ(0, payload_left);
return true;
}
size_t RtpPacketizerH264::PacketizeStapA(size_t fragment_index) {
// Aggregate fragments into one packet (STAP-A).
size_t payload_size_left = limits_.max_payload_len;
if (input_fragments_.size() == 1)
payload_size_left -= limits_.single_packet_reduction_len;
else if (fragment_index == 0)
payload_size_left -= limits_.first_packet_reduction_len;
int aggregated_fragments = 0;
size_t fragment_headers_length = 0;
const Fragment* fragment = &input_fragments_[fragment_index];
RTC_CHECK_GE(payload_size_left, fragment->length);
++num_packets_left_;
auto payload_size_needed = [&] {
size_t fragment_size = fragment->length + fragment_headers_length;
if (input_fragments_.size() == 1) {
// Single fragment, single packet, payload_size_left already adjusted
// with limits_.single_packet_reduction_len.
return fragment_size;
}
if (fragment_index == input_fragments_.size() - 1) {
// Last fragment, so StrapA might be the last packet.
return fragment_size + limits_.last_packet_reduction_len;
}
return fragment_size;
};
while (payload_size_left >= payload_size_needed()) {
RTC_CHECK_GT(fragment->length, 0);
packets_.push(PacketUnit(*fragment, aggregated_fragments == 0, false, true,
fragment->buffer[0]));
payload_size_left -= fragment->length;
payload_size_left -= fragment_headers_length;
fragment_headers_length = kLengthFieldSize;
// If we are going to try to aggregate more fragments into this packet
// we need to add the STAP-A NALU header and a length field for the first
// NALU of this packet.
if (aggregated_fragments == 0)
fragment_headers_length += kNalHeaderSize + kLengthFieldSize;
++aggregated_fragments;
// Next fragment.
++fragment_index;
if (fragment_index == input_fragments_.size())
break;
fragment = &input_fragments_[fragment_index];
}
RTC_CHECK_GT(aggregated_fragments, 0);
packets_.back().last_fragment = true;
return fragment_index;
}
bool RtpPacketizerH264::PacketizeSingleNalu(size_t fragment_index) {
// Add a single NALU to the queue, no aggregation.
size_t payload_size_left = limits_.max_payload_len;
if (input_fragments_.size() == 1)
payload_size_left -= limits_.single_packet_reduction_len;
else if (fragment_index == 0)
payload_size_left -= limits_.first_packet_reduction_len;
else if (fragment_index + 1 == input_fragments_.size())
payload_size_left -= limits_.last_packet_reduction_len;
const Fragment* fragment = &input_fragments_[fragment_index];
if (payload_size_left < fragment->length) {
RTC_LOG(LS_ERROR) << "Failed to fit a fragment to packet in SingleNalu "
"packetization mode. Payload size left "
<< payload_size_left << ", fragment length "
<< fragment->length << ", packet capacity "
<< limits_.max_payload_len;
return false;
}
RTC_CHECK_GT(fragment->length, 0u);
packets_.push(PacketUnit(*fragment, true /* first */, true /* last */,
false /* aggregated */, fragment->buffer[0]));
++num_packets_left_;
return true;
}
bool RtpPacketizerH264::NextPacket(RtpPacketToSend* rtp_packet) {
RTC_DCHECK(rtp_packet);
if (packets_.empty()) {
return false;
}
PacketUnit packet = packets_.front();
if (packet.first_fragment && packet.last_fragment) {
// Single NAL unit packet.
size_t bytes_to_send = packet.source_fragment.length;
uint8_t* buffer = rtp_packet->AllocatePayload(bytes_to_send);
memcpy(buffer, packet.source_fragment.buffer, bytes_to_send);
packets_.pop();
input_fragments_.pop_front();
} else if (packet.aggregated) {
NextAggregatePacket(rtp_packet);
} else {
NextFragmentPacket(rtp_packet);
}
rtp_packet->SetMarker(packets_.empty());
--num_packets_left_;
return true;
}
void RtpPacketizerH264::NextAggregatePacket(RtpPacketToSend* rtp_packet) {
// Reserve maximum available payload, set actual payload size later.
size_t payload_capacity = rtp_packet->FreeCapacity();
RTC_CHECK_GE(payload_capacity, kNalHeaderSize);
uint8_t* buffer = rtp_packet->AllocatePayload(payload_capacity);
RTC_DCHECK(buffer);
PacketUnit* packet = &packets_.front();
RTC_CHECK(packet->first_fragment);
// STAP-A NALU header.
buffer[0] = (packet->header & (kFBit | kNriMask)) | H264::NaluType::kStapA;
size_t index = kNalHeaderSize;
bool is_last_fragment = packet->last_fragment;
while (packet->aggregated) {
const Fragment& fragment = packet->source_fragment;
RTC_CHECK_LE(index + kLengthFieldSize + fragment.length, payload_capacity);
// Add NAL unit length field.
ByteWriter<uint16_t>::WriteBigEndian(&buffer[index], fragment.length);
index += kLengthFieldSize;
// Add NAL unit.
memcpy(&buffer[index], fragment.buffer, fragment.length);
index += fragment.length;
packets_.pop();
input_fragments_.pop_front();
if (is_last_fragment)
break;
packet = &packets_.front();
is_last_fragment = packet->last_fragment;
}
RTC_CHECK(is_last_fragment);
rtp_packet->SetPayloadSize(index);
}
void RtpPacketizerH264::NextFragmentPacket(RtpPacketToSend* rtp_packet) {
PacketUnit* packet = &packets_.front();
// NAL unit fragmented over multiple packets (FU-A).
// We do not send original NALU header, so it will be replaced by the
// FU indicator header of the first packet.
uint8_t fu_indicator =
(packet->header & (kFBit | kNriMask)) | H264::NaluType::kFuA;
uint8_t fu_header = 0;
// S | E | R | 5 bit type.
fu_header |= (packet->first_fragment ? kSBit : 0);
fu_header |= (packet->last_fragment ? kEBit : 0);
uint8_t type = packet->header & kTypeMask;
fu_header |= type;
const Fragment& fragment = packet->source_fragment;
uint8_t* buffer =
rtp_packet->AllocatePayload(kFuAHeaderSize + fragment.length);
buffer[0] = fu_indicator;
buffer[1] = fu_header;
memcpy(buffer + kFuAHeaderSize, fragment.buffer, fragment.length);
if (packet->last_fragment)
input_fragments_.pop_front();
packets_.pop();
}
RtpDepacketizerH264::RtpDepacketizerH264() : offset_(0), length_(0) {}
RtpDepacketizerH264::~RtpDepacketizerH264() {}
bool RtpDepacketizerH264::Parse(ParsedPayload* parsed_payload,
const uint8_t* payload_data,
size_t payload_data_length) {
RTC_CHECK(parsed_payload != nullptr);
if (payload_data_length == 0) {
RTC_LOG(LS_ERROR) << "Empty payload.";
return false;
}
offset_ = 0;
length_ = payload_data_length;
modified_buffer_.reset();
uint8_t nal_type = payload_data[0] & kTypeMask;
parsed_payload->video_header()
.video_type_header.emplace<RTPVideoHeaderH264>();
if (nal_type == H264::NaluType::kFuA) {
// Fragmented NAL units (FU-A).
if (!ParseFuaNalu(parsed_payload, payload_data))
return false;
} else {
// We handle STAP-A and single NALU's the same way here. The jitter buffer
// will depacketize the STAP-A into NAL units later.
// TODO(sprang): Parse STAP-A offsets here and store in fragmentation vec.
if (!ProcessStapAOrSingleNalu(parsed_payload, payload_data))
return false;
}
const uint8_t* payload =
modified_buffer_ ? modified_buffer_->data() : payload_data;
parsed_payload->payload = payload + offset_;
parsed_payload->payload_length = length_;
return true;
}
bool RtpDepacketizerH264::ProcessStapAOrSingleNalu(
ParsedPayload* parsed_payload,
const uint8_t* payload_data) {
parsed_payload->video_header().width = 0;
parsed_payload->video_header().height = 0;
parsed_payload->video_header().codec = kVideoCodecH264;
parsed_payload->video_header().simulcastIdx = 0;
parsed_payload->video_header().is_first_packet_in_frame = true;
auto& h264_header = absl::get<RTPVideoHeaderH264>(
parsed_payload->video_header().video_type_header);
const uint8_t* nalu_start = payload_data + kNalHeaderSize;
const size_t nalu_length = length_ - kNalHeaderSize;
uint8_t nal_type = payload_data[0] & kTypeMask;
std::vector<size_t> nalu_start_offsets;
if (nal_type == H264::NaluType::kStapA) {
// Skip the StapA header (StapA NAL type + length).
if (length_ <= kStapAHeaderSize) {
RTC_LOG(LS_ERROR) << "StapA header truncated.";
return false;
}
if (!ParseStapAStartOffsets(nalu_start, nalu_length, &nalu_start_offsets)) {
RTC_LOG(LS_ERROR) << "StapA packet with incorrect NALU packet lengths.";
return false;
}
h264_header.packetization_type = kH264StapA;
nal_type = payload_data[kStapAHeaderSize] & kTypeMask;
} else {
h264_header.packetization_type = kH264SingleNalu;
nalu_start_offsets.push_back(0);
}
h264_header.nalu_type = nal_type;
parsed_payload->frame_type = kVideoFrameDelta;
nalu_start_offsets.push_back(length_ + kLengthFieldSize); // End offset.
for (size_t i = 0; i < nalu_start_offsets.size() - 1; ++i) {
size_t start_offset = nalu_start_offsets[i];
// End offset is actually start offset for next unit, excluding length field
// so remove that from this units length.
size_t end_offset = nalu_start_offsets[i + 1] - kLengthFieldSize;
if (end_offset - start_offset < H264::kNaluTypeSize) {
RTC_LOG(LS_ERROR) << "STAP-A packet too short";
return false;
}
NaluInfo nalu;
nalu.type = payload_data[start_offset] & kTypeMask;
nalu.sps_id = -1;
nalu.pps_id = -1;
start_offset += H264::kNaluTypeSize;
switch (nalu.type) {
case H264::NaluType::kSps: {
// Check if VUI is present in SPS and if it needs to be modified to
// avoid
// excessive decoder latency.
// Copy any previous data first (likely just the first header).
std::unique_ptr<rtc::Buffer> output_buffer(new rtc::Buffer());
if (start_offset)
output_buffer->AppendData(payload_data, start_offset);
absl::optional<SpsParser::SpsState> sps;
SpsVuiRewriter::ParseResult result = SpsVuiRewriter::ParseAndRewriteSps(
&payload_data[start_offset], end_offset - start_offset, &sps,
output_buffer.get());
switch (result) {
case SpsVuiRewriter::ParseResult::kVuiRewritten:
if (modified_buffer_) {
RTC_LOG(LS_WARNING)
<< "More than one H264 SPS NAL units needing "
"rewriting found within a single STAP-A packet. "
"Keeping the first and rewriting the last.";
}
// Rewrite length field to new SPS size.
if (h264_header.packetization_type == kH264StapA) {
size_t length_field_offset =
start_offset - (H264::kNaluTypeSize + kLengthFieldSize);
// Stap-A Length includes payload data and type header.
size_t rewritten_size =
output_buffer->size() - start_offset + H264::kNaluTypeSize;
ByteWriter<uint16_t>::WriteBigEndian(
&(*output_buffer)[length_field_offset], rewritten_size);
}
// Append rest of packet.
output_buffer->AppendData(
&payload_data[end_offset],
nalu_length + kNalHeaderSize - end_offset);
modified_buffer_ = std::move(output_buffer);
length_ = modified_buffer_->size();
RTC_HISTOGRAM_ENUMERATION(kSpsValidHistogramName,
SpsValidEvent::kReceivedSpsRewritten,
SpsValidEvent::kSpsRewrittenMax);
break;
case SpsVuiRewriter::ParseResult::kPocOk:
RTC_HISTOGRAM_ENUMERATION(kSpsValidHistogramName,
SpsValidEvent::kReceivedSpsPocOk,
SpsValidEvent::kSpsRewrittenMax);
break;
case SpsVuiRewriter::ParseResult::kVuiOk:
RTC_HISTOGRAM_ENUMERATION(kSpsValidHistogramName,
SpsValidEvent::kReceivedSpsVuiOk,
SpsValidEvent::kSpsRewrittenMax);
break;
case SpsVuiRewriter::ParseResult::kFailure:
RTC_HISTOGRAM_ENUMERATION(kSpsValidHistogramName,
SpsValidEvent::kReceivedSpsParseFailure,
SpsValidEvent::kSpsRewrittenMax);
break;
}
if (sps) {
parsed_payload->video_header().width = sps->width;
parsed_payload->video_header().height = sps->height;
nalu.sps_id = sps->id;
} else {
RTC_LOG(LS_WARNING) << "Failed to parse SPS id from SPS slice.";
}
parsed_payload->frame_type = kVideoFrameKey;
break;
}
case H264::NaluType::kPps: {
uint32_t pps_id;
uint32_t sps_id;
if (PpsParser::ParsePpsIds(&payload_data[start_offset],
end_offset - start_offset, &pps_id,
&sps_id)) {
nalu.pps_id = pps_id;
nalu.sps_id = sps_id;
} else {
RTC_LOG(LS_WARNING)
<< "Failed to parse PPS id and SPS id from PPS slice.";
}
break;
}
case H264::NaluType::kIdr:
parsed_payload->frame_type = kVideoFrameKey;
RTC_FALLTHROUGH();
case H264::NaluType::kSlice: {
absl::optional<uint32_t> pps_id = PpsParser::ParsePpsIdFromSlice(
&payload_data[start_offset], end_offset - start_offset);
if (pps_id) {
nalu.pps_id = *pps_id;
} else {
RTC_LOG(LS_WARNING) << "Failed to parse PPS id from slice of type: "
<< static_cast<int>(nalu.type);
}
break;
}
// Slices below don't contain SPS or PPS ids.
case H264::NaluType::kAud:
case H264::NaluType::kEndOfSequence:
case H264::NaluType::kEndOfStream:
case H264::NaluType::kFiller:
case H264::NaluType::kSei:
break;
case H264::NaluType::kStapA:
case H264::NaluType::kFuA:
RTC_LOG(LS_WARNING) << "Unexpected STAP-A or FU-A received.";
return false;
}
if (h264_header.nalus_length == kMaxNalusPerPacket) {
RTC_LOG(LS_WARNING)
<< "Received packet containing more than " << kMaxNalusPerPacket
<< " NAL units. Will not keep track sps and pps ids for all of them.";
} else {
h264_header.nalus[h264_header.nalus_length++] = nalu;
}
}
return true;
}
bool RtpDepacketizerH264::ParseFuaNalu(
RtpDepacketizer::ParsedPayload* parsed_payload,
const uint8_t* payload_data) {
if (length_ < kFuAHeaderSize) {
RTC_LOG(LS_ERROR) << "FU-A NAL units truncated.";
return false;
}
uint8_t fnri = payload_data[0] & (kFBit | kNriMask);
uint8_t original_nal_type = payload_data[1] & kTypeMask;
bool first_fragment = (payload_data[1] & kSBit) > 0;
NaluInfo nalu;
nalu.type = original_nal_type;
nalu.sps_id = -1;
nalu.pps_id = -1;
if (first_fragment) {
offset_ = 0;
length_ -= kNalHeaderSize;
absl::optional<uint32_t> pps_id = PpsParser::ParsePpsIdFromSlice(
payload_data + 2 * kNalHeaderSize, length_ - kNalHeaderSize);
if (pps_id) {
nalu.pps_id = *pps_id;
} else {
RTC_LOG(LS_WARNING)
<< "Failed to parse PPS from first fragment of FU-A NAL "
"unit with original type: "
<< static_cast<int>(nalu.type);
}
uint8_t original_nal_header = fnri | original_nal_type;
modified_buffer_.reset(new rtc::Buffer());
modified_buffer_->AppendData(payload_data + kNalHeaderSize, length_);
(*modified_buffer_)[0] = original_nal_header;
} else {
offset_ = kFuAHeaderSize;
length_ -= kFuAHeaderSize;
}
if (original_nal_type == H264::NaluType::kIdr) {
parsed_payload->frame_type = kVideoFrameKey;
} else {
parsed_payload->frame_type = kVideoFrameDelta;
}
parsed_payload->video_header().width = 0;
parsed_payload->video_header().height = 0;
parsed_payload->video_header().codec = kVideoCodecH264;
parsed_payload->video_header().simulcastIdx = 0;
parsed_payload->video_header().is_first_packet_in_frame = first_fragment;
auto& h264_header = absl::get<RTPVideoHeaderH264>(
parsed_payload->video_header().video_type_header);
h264_header.packetization_type = kH264FuA;
h264_header.nalu_type = original_nal_type;
if (first_fragment) {
h264_header.nalus[h264_header.nalus_length] = nalu;
h264_header.nalus_length = 1;
}
return true;
}
} // namespace webrtc
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