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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.
*/
#ifndef MODULES_VIDEO_CODING_PACKET_BUFFER_H_
#define MODULES_VIDEO_CODING_PACKET_BUFFER_H_
#include <cstddef>
#include <cstdint>
#include <memory>
#include <optional>
#include <set>
#include <vector>
#include "absl/base/attributes.h"
#include "api/video/video_codec_type.h"
#include "modules/rtp_rtcp/source/rtp_packet_received.h"
#include "modules/rtp_rtcp/source/rtp_video_header.h"
#include "rtc_base/copy_on_write_buffer.h"
#include "rtc_base/numerics/sequence_number_util.h"
namespace webrtc {
namespace video_coding {
class PacketBuffer {
public:
struct Packet {
Packet() = default;
Packet(const RtpPacketReceived& rtp_packet,
int64_t sequence_number,
const RTPVideoHeader& video_header);
Packet(const Packet&) = delete;
Packet(Packet&&) = delete;
Packet& operator=(const Packet&) = delete;
Packet& operator=(Packet&&) = delete;
~Packet() = default;
VideoCodecType codec() const { return video_header.codec; }
int width() const { return video_header.width; }
int height() const { return video_header.height; }
bool is_first_packet_in_frame() const {
return video_header.is_first_packet_in_frame;
}
bool is_last_packet_in_frame() const {
return video_header.is_last_packet_in_frame;
}
uint16_t seq_num() const { return static_cast<uint16_t>(sequence_number); }
// If all its previous packets have been inserted into the packet buffer.
// Set and used internally by the PacketBuffer.
bool continuous = false;
bool marker_bit = false;
uint8_t payload_type = 0;
int64_t sequence_number = 0;
uint32_t timestamp = 0;
int times_nacked = -1;
CopyOnWriteBuffer video_payload;
RTPVideoHeader video_header;
};
struct InsertResult {
std::vector<std::unique_ptr<Packet>> packets;
// Indicates if the packet buffer was cleared, which means that a key
// frame request should be sent.
bool buffer_cleared = false;
};
// Both `start_buffer_size` and `max_buffer_size` must be a power of 2.
PacketBuffer(size_t start_buffer_size, size_t max_buffer_size);
~PacketBuffer();
ABSL_MUST_USE_RESULT InsertResult
InsertPacket(std::unique_ptr<Packet> packet);
ABSL_MUST_USE_RESULT InsertResult InsertPadding(uint16_t seq_num);
void ClearTo(uint16_t seq_num);
void Clear();
void ForceSpsPpsIdrIsH264Keyframe();
void ResetSpsPpsIdrIsH264Keyframe();
private:
void ClearInternal();
// Tries to expand the buffer.
bool ExpandBufferSize();
// Test if all previous packets has arrived for the given sequence number.
bool PotentialNewFrame(uint16_t seq_num) const;
// Test if all packets of a frame has arrived, and if so, returns packets to
// create frames.
std::vector<std::unique_ptr<Packet>> FindFrames(uint16_t seq_num);
void UpdateMissingPackets(uint16_t seq_num);
// buffer_.size() and max_size_ must always be a power of two.
const size_t max_size_;
// The fist sequence number currently in the buffer.
uint16_t first_seq_num_;
// If the packet buffer has received its first packet.
bool first_packet_received_;
// If the buffer is cleared to `first_seq_num_`.
bool is_cleared_to_first_seq_num_;
// Buffer that holds the the inserted packets and information needed to
// determine continuity between them.
std::vector<std::unique_ptr<Packet>> buffer_;
std::optional<uint16_t> newest_inserted_seq_num_;
std::set<uint16_t, DescendingSeqNumComp<uint16_t>> missing_packets_;
std::set<uint16_t, DescendingSeqNumComp<uint16_t>> received_padding_;
// Indicates if we should require SPS, PPS, and IDR for a particular
// RTP timestamp to treat the corresponding frame as a keyframe.
bool sps_pps_idr_is_h264_keyframe_;
};
} // namespace video_coding
} // namespace webrtc
#endif // MODULES_VIDEO_CODING_PACKET_BUFFER_H_
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