blob: 8b6de047ca5bb6aa3e7f542dacdd8f48cf6c5559 [file] [log] [blame]
/*
* 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 "webrtc/modules/video_coding/packet_buffer.h"
#include <algorithm>
#include <limits>
#include <utility>
#include "webrtc/common_video/h264/h264_common.h"
#include "webrtc/modules/video_coding/frame_object.h"
#include "webrtc/rtc_base/atomicops.h"
#include "webrtc/rtc_base/checks.h"
#include "webrtc/rtc_base/logging.h"
#include "webrtc/system_wrappers/include/clock.h"
namespace webrtc {
namespace video_coding {
rtc::scoped_refptr<PacketBuffer> PacketBuffer::Create(
Clock* clock,
size_t start_buffer_size,
size_t max_buffer_size,
OnReceivedFrameCallback* received_frame_callback) {
return rtc::scoped_refptr<PacketBuffer>(new PacketBuffer(
clock, start_buffer_size, max_buffer_size, received_frame_callback));
}
PacketBuffer::PacketBuffer(Clock* clock,
size_t start_buffer_size,
size_t max_buffer_size,
OnReceivedFrameCallback* received_frame_callback)
: clock_(clock),
size_(start_buffer_size),
max_size_(max_buffer_size),
first_seq_num_(0),
first_packet_received_(false),
is_cleared_to_first_seq_num_(false),
data_buffer_(start_buffer_size),
sequence_buffer_(start_buffer_size),
received_frame_callback_(received_frame_callback) {
RTC_DCHECK_LE(start_buffer_size, max_buffer_size);
// Buffer size must always be a power of 2.
RTC_DCHECK((start_buffer_size & (start_buffer_size - 1)) == 0);
RTC_DCHECK((max_buffer_size & (max_buffer_size - 1)) == 0);
}
PacketBuffer::~PacketBuffer() {
Clear();
}
bool PacketBuffer::InsertPacket(VCMPacket* packet) {
std::vector<std::unique_ptr<RtpFrameObject>> found_frames;
{
rtc::CritScope lock(&crit_);
uint16_t seq_num = packet->seqNum;
size_t index = seq_num % size_;
if (!first_packet_received_) {
first_seq_num_ = seq_num;
first_packet_received_ = true;
} else if (AheadOf(first_seq_num_, seq_num)) {
// If we have explicitly cleared past this packet then it's old,
// don't insert it.
if (is_cleared_to_first_seq_num_) {
delete[] packet->dataPtr;
packet->dataPtr = nullptr;
return false;
}
first_seq_num_ = seq_num;
}
if (sequence_buffer_[index].used) {
// Duplicate packet, just delete the payload.
if (data_buffer_[index].seqNum == packet->seqNum) {
delete[] packet->dataPtr;
packet->dataPtr = nullptr;
return true;
}
// The packet buffer is full, try to expand the buffer.
while (ExpandBufferSize() && sequence_buffer_[seq_num % size_].used) {
}
index = seq_num % size_;
// Packet buffer is still full.
if (sequence_buffer_[index].used) {
delete[] packet->dataPtr;
packet->dataPtr = nullptr;
return false;
}
}
sequence_buffer_[index].frame_begin = packet->is_first_packet_in_frame;
sequence_buffer_[index].frame_end = packet->markerBit;
sequence_buffer_[index].seq_num = packet->seqNum;
sequence_buffer_[index].continuous = false;
sequence_buffer_[index].frame_created = false;
sequence_buffer_[index].used = true;
data_buffer_[index] = *packet;
packet->dataPtr = nullptr;
UpdateMissingPackets(packet->seqNum);
int64_t now_ms = clock_->TimeInMilliseconds();
last_received_packet_ms_ = rtc::Optional<int64_t>(now_ms);
if (packet->frameType == kVideoFrameKey)
last_received_keyframe_packet_ms_ = rtc::Optional<int64_t>(now_ms);
found_frames = FindFrames(seq_num);
}
for (std::unique_ptr<RtpFrameObject>& frame : found_frames)
received_frame_callback_->OnReceivedFrame(std::move(frame));
return true;
}
void PacketBuffer::ClearTo(uint16_t seq_num) {
rtc::CritScope lock(&crit_);
// If the packet buffer was cleared between a frame was created and returned.
if (!first_packet_received_)
return;
is_cleared_to_first_seq_num_ = true;
while (AheadOrAt<uint16_t>(seq_num, first_seq_num_)) {
size_t index = first_seq_num_ % size_;
delete[] data_buffer_[index].dataPtr;
data_buffer_[index].dataPtr = nullptr;
sequence_buffer_[index].used = false;
++first_seq_num_;
}
missing_packets_.erase(missing_packets_.begin(),
missing_packets_.upper_bound(seq_num));
}
void PacketBuffer::Clear() {
rtc::CritScope lock(&crit_);
for (size_t i = 0; i < size_; ++i) {
delete[] data_buffer_[i].dataPtr;
data_buffer_[i].dataPtr = nullptr;
sequence_buffer_[i].used = false;
}
first_packet_received_ = false;
is_cleared_to_first_seq_num_ = false;
last_received_packet_ms_.reset();
last_received_keyframe_packet_ms_.reset();
newest_inserted_seq_num_.reset();
missing_packets_.clear();
}
void PacketBuffer::PaddingReceived(uint16_t seq_num) {
std::vector<std::unique_ptr<RtpFrameObject>> found_frames;
{
rtc::CritScope lock(&crit_);
UpdateMissingPackets(seq_num);
found_frames = FindFrames(static_cast<uint16_t>(seq_num + 1));
}
for (std::unique_ptr<RtpFrameObject>& frame : found_frames)
received_frame_callback_->OnReceivedFrame(std::move(frame));
}
rtc::Optional<int64_t> PacketBuffer::LastReceivedPacketMs() const {
rtc::CritScope lock(&crit_);
return last_received_packet_ms_;
}
rtc::Optional<int64_t> PacketBuffer::LastReceivedKeyframePacketMs() const {
rtc::CritScope lock(&crit_);
return last_received_keyframe_packet_ms_;
}
bool PacketBuffer::ExpandBufferSize() {
if (size_ == max_size_) {
LOG(LS_WARNING) << "PacketBuffer is already at max size (" << max_size_
<< "), failed to increase size. Clearing PacketBuffer.";
Clear();
return false;
}
size_t new_size = std::min(max_size_, 2 * size_);
std::vector<VCMPacket> new_data_buffer(new_size);
std::vector<ContinuityInfo> new_sequence_buffer(new_size);
for (size_t i = 0; i < size_; ++i) {
if (sequence_buffer_[i].used) {
size_t index = sequence_buffer_[i].seq_num % new_size;
new_sequence_buffer[index] = sequence_buffer_[i];
new_data_buffer[index] = data_buffer_[i];
}
}
size_ = new_size;
sequence_buffer_ = std::move(new_sequence_buffer);
data_buffer_ = std::move(new_data_buffer);
LOG(LS_INFO) << "PacketBuffer size expanded to " << new_size;
return true;
}
bool PacketBuffer::PotentialNewFrame(uint16_t seq_num) const {
size_t index = seq_num % size_;
int prev_index = index > 0 ? index - 1 : size_ - 1;
if (!sequence_buffer_[index].used)
return false;
if (sequence_buffer_[index].seq_num != seq_num)
return false;
if (sequence_buffer_[index].frame_created)
return false;
if (sequence_buffer_[index].frame_begin)
return true;
if (!sequence_buffer_[prev_index].used)
return false;
if (sequence_buffer_[prev_index].frame_created)
return false;
if (sequence_buffer_[prev_index].seq_num !=
static_cast<uint16_t>(sequence_buffer_[index].seq_num - 1)) {
return false;
}
if (sequence_buffer_[prev_index].continuous)
return true;
return false;
}
std::vector<std::unique_ptr<RtpFrameObject>> PacketBuffer::FindFrames(
uint16_t seq_num) {
std::vector<std::unique_ptr<RtpFrameObject>> found_frames;
for (size_t i = 0; i < size_ && PotentialNewFrame(seq_num); ++i) {
size_t index = seq_num % size_;
sequence_buffer_[index].continuous = true;
// If all packets of the frame is continuous, find the first packet of the
// frame and create an RtpFrameObject.
if (sequence_buffer_[index].frame_end) {
size_t frame_size = 0;
int max_nack_count = -1;
uint16_t start_seq_num = seq_num;
// Find the start index by searching backward until the packet with
// the |frame_begin| flag is set.
int start_index = index;
bool is_h264 = data_buffer_[start_index].codec == kVideoCodecH264;
bool is_h264_keyframe = false;
int64_t frame_timestamp = data_buffer_[start_index].timestamp;
// Since packet at |data_buffer_[index]| is already part of the frame
// we will have at most |size_ - 1| packets left to check.
for (size_t j = 0; j < size_ - 1; ++j) {
frame_size += data_buffer_[start_index].sizeBytes;
max_nack_count =
std::max(max_nack_count, data_buffer_[start_index].timesNacked);
sequence_buffer_[start_index].frame_created = true;
if (!is_h264 && sequence_buffer_[start_index].frame_begin)
break;
if (is_h264 && !is_h264_keyframe) {
const RTPVideoHeaderH264& header =
data_buffer_[start_index].video_header.codecHeader.H264;
for (size_t i = 0; i < header.nalus_length; ++i) {
if (header.nalus[i].type == H264::NaluType::kIdr) {
is_h264_keyframe = true;
break;
}
}
}
start_index = start_index > 0 ? start_index - 1 : size_ - 1;
// In the case of H264 we don't have a frame_begin bit (yes,
// |frame_begin| might be set to true but that is a lie). So instead
// we traverese backwards as long as we have a previous packet and
// the timestamp of that packet is the same as this one. This may cause
// the PacketBuffer to hand out incomplete frames.
// See: https://bugs.chromium.org/p/webrtc/issues/detail?id=7106
if (is_h264 &&
(!sequence_buffer_[start_index].used ||
data_buffer_[start_index].timestamp != frame_timestamp)) {
break;
}
--start_seq_num;
}
// If this is H264 but not a keyframe, make sure there are no gaps in the
// packet sequence numbers up until this point.
if (is_h264 && !is_h264_keyframe &&
missing_packets_.upper_bound(start_seq_num) !=
missing_packets_.begin()) {
uint16_t stop_index = (index + 1) % size_;
while (start_index != stop_index) {
sequence_buffer_[start_index].frame_created = false;
start_index = (start_index + 1) % size_;
}
return found_frames;
}
missing_packets_.erase(missing_packets_.begin(),
missing_packets_.upper_bound(seq_num));
found_frames.emplace_back(
new RtpFrameObject(this, start_seq_num, seq_num, frame_size,
max_nack_count, clock_->TimeInMilliseconds()));
}
++seq_num;
}
return found_frames;
}
void PacketBuffer::ReturnFrame(RtpFrameObject* frame) {
rtc::CritScope lock(&crit_);
size_t index = frame->first_seq_num() % size_;
size_t end = (frame->last_seq_num() + 1) % size_;
uint16_t seq_num = frame->first_seq_num();
while (index != end) {
if (sequence_buffer_[index].seq_num == seq_num) {
delete[] data_buffer_[index].dataPtr;
data_buffer_[index].dataPtr = nullptr;
sequence_buffer_[index].used = false;
}
index = (index + 1) % size_;
++seq_num;
}
}
bool PacketBuffer::GetBitstream(const RtpFrameObject& frame,
uint8_t* destination) {
rtc::CritScope lock(&crit_);
size_t index = frame.first_seq_num() % size_;
size_t end = (frame.last_seq_num() + 1) % size_;
uint16_t seq_num = frame.first_seq_num();
while (index != end) {
if (!sequence_buffer_[index].used ||
sequence_buffer_[index].seq_num != seq_num) {
return false;
}
const uint8_t* source = data_buffer_[index].dataPtr;
size_t length = data_buffer_[index].sizeBytes;
memcpy(destination, source, length);
destination += length;
index = (index + 1) % size_;
++seq_num;
}
return true;
}
VCMPacket* PacketBuffer::GetPacket(uint16_t seq_num) {
size_t index = seq_num % size_;
if (!sequence_buffer_[index].used ||
seq_num != sequence_buffer_[index].seq_num) {
return nullptr;
}
return &data_buffer_[index];
}
int PacketBuffer::AddRef() const {
return rtc::AtomicOps::Increment(&ref_count_);
}
int PacketBuffer::Release() const {
int count = rtc::AtomicOps::Decrement(&ref_count_);
if (!count) {
delete this;
}
return count;
}
void PacketBuffer::UpdateMissingPackets(uint16_t seq_num) {
if (!newest_inserted_seq_num_)
newest_inserted_seq_num_ = rtc::Optional<uint16_t>(seq_num);
const int kMaxPaddingAge = 1000;
if (AheadOf(seq_num, *newest_inserted_seq_num_)) {
uint16_t old_seq_num = seq_num - kMaxPaddingAge;
auto erase_to = missing_packets_.lower_bound(old_seq_num);
missing_packets_.erase(missing_packets_.begin(), erase_to);
// Guard against inserting a large amount of missing packets if there is a
// jump in the sequence number.
if (AheadOf(old_seq_num, *newest_inserted_seq_num_))
*newest_inserted_seq_num_ = old_seq_num;
++*newest_inserted_seq_num_;
while (AheadOf(seq_num, *newest_inserted_seq_num_)) {
missing_packets_.insert(*newest_inserted_seq_num_);
++*newest_inserted_seq_num_;
}
} else {
missing_packets_.erase(seq_num);
}
}
} // namespace video_coding
} // namespace webrtc