blob: 0c6f204edbd72979838f28dece9a37f269fabc4d [file] [log] [blame]
* Copyright (c) 2012 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 <stdint.h>
#include <list>
#include <memory>
#include "api/audio_codecs/audio_decoder.h"
#include "api/neteq/tick_timer.h"
#include "api/rtp_packet_info.h"
#include "rtc_base/buffer.h"
#include "rtc_base/checks.h"
namespace webrtc {
// Struct for holding RTP packets.
struct Packet {
struct Priority {
Priority() : codec_level(0), red_level(0) {}
Priority(int codec_level, int red_level)
: codec_level(codec_level), red_level(red_level) {
int codec_level;
int red_level;
// Priorities are sorted low-to-high, first on the level the codec
// prioritizes it, then on the level of RED packet it is; i.e. if it is a
// primary or secondary payload of a RED packet. For example: with Opus, an
// Fec packet (which the decoder prioritizes lower than a regular packet)
// will not be used if there is _any_ RED payload for the same
// timeframe. The highest priority packet will have levels {0, 0}. Negative
// priorities are not allowed.
bool operator<(const Priority& b) const {
if (codec_level == b.codec_level)
return red_level < b.red_level;
return codec_level < b.codec_level;
bool operator==(const Priority& b) const {
return codec_level == b.codec_level && red_level == b.red_level;
bool operator!=(const Priority& b) const { return !(*this == b); }
bool operator>(const Priority& b) const { return b < *this; }
bool operator<=(const Priority& b) const { return !(b > *this); }
bool operator>=(const Priority& b) const { return !(b < *this); }
void CheckInvariant() const {
RTC_DCHECK_GE(codec_level, 0);
RTC_DCHECK_GE(red_level, 0);
uint32_t timestamp;
uint16_t sequence_number;
uint8_t payload_type;
// Datagram excluding RTP header and header extension.
rtc::Buffer payload;
Priority priority;
RtpPacketInfo packet_info;
std::unique_ptr<TickTimer::Stopwatch> waiting_time;
std::unique_ptr<AudioDecoder::EncodedAudioFrame> frame;
Packet(Packet&& b);
// Packets should generally be moved around but sometimes it's useful to make
// a copy, for example for testing purposes. NOTE: Will only work for
// un-parsed packets, i.e. `frame` must be unset. The payload will, however,
// be copied. `waiting_time` will also not be copied.
Packet Clone() const;
Packet& operator=(Packet&& b);
// Comparison operators. Establish a packet ordering based on (1) timestamp,
// (2) sequence number and (3) redundancy.
// Timestamp and sequence numbers are compared taking wrap-around into
// account. For two packets with the same sequence number and timestamp a
// primary payload is considered "smaller" than a secondary.
bool operator==(const Packet& rhs) const {
return (this->timestamp == rhs.timestamp &&
this->sequence_number == rhs.sequence_number &&
this->priority == rhs.priority);
bool operator!=(const Packet& rhs) const { return !operator==(rhs); }
bool operator<(const Packet& rhs) const {
if (this->timestamp == rhs.timestamp) {
if (this->sequence_number == rhs.sequence_number) {
// Timestamp and sequence numbers are identical - deem the left hand
// side to be "smaller" (i.e., "earlier") if it has higher priority.
return this->priority < rhs.priority;
return (static_cast<uint16_t>(rhs.sequence_number -
this->sequence_number) < 0xFFFF / 2);
return (static_cast<uint32_t>(rhs.timestamp - this->timestamp) <
0xFFFFFFFF / 2);
bool operator>(const Packet& rhs) const { return rhs.operator<(*this); }
bool operator<=(const Packet& rhs) const { return !operator>(rhs); }
bool operator>=(const Packet& rhs) const { return !operator<(rhs); }
bool empty() const { return !frame && payload.empty(); }
// A list of packets.
typedef std::list<Packet> PacketList;
} // namespace webrtc