1 /* 2 * Copyright (c) 2012 The WebRTC project authors. All Rights Reserved. 3 * 4 * Use of this source code is governed by a BSD-style license 5 * that can be found in the LICENSE file in the root of the source 6 * tree. An additional intellectual property rights grant can be found 7 * in the file PATENTS. All contributing project authors may 8 * be found in the AUTHORS file in the root of the source tree. 9 */ 10 11 #ifndef WEBRTC_MODULES_AUDIO_CODING_NETEQ_PACKET_H_ 12 #define WEBRTC_MODULES_AUDIO_CODING_NETEQ_PACKET_H_ 13 14 #include <list> 15 16 #include "webrtc/modules/interface/module_common_types.h" 17 #include "webrtc/typedefs.h" 18 19 namespace webrtc { 20 21 // Struct for holding RTP packets. 22 struct Packet { 23 RTPHeader header; 24 uint8_t* payload; // Datagram excluding RTP header and header extension. 25 int payload_length; 26 bool primary; // Primary, i.e., not redundant payload. 27 int waiting_time; 28 bool sync_packet; 29 30 // Constructor. 31 Packet() 32 : payload(NULL), 33 payload_length(0), 34 primary(true), 35 waiting_time(0), 36 sync_packet(false) { 37 } 38 39 // Comparison operators. Establish a packet ordering based on (1) timestamp, 40 // (2) sequence number, (3) regular packet vs sync-packet and (4) redundancy. 41 // Timestamp and sequence numbers are compared taking wrap-around into 42 // account. If both timestamp and sequence numbers are identical and one of 43 // the packets is sync-packet, the regular packet is considered earlier. For 44 // two regular packets with the same sequence number and timestamp a primary 45 // payload is considered "smaller" than a secondary. 46 bool operator==(const Packet& rhs) const { 47 return (this->header.timestamp == rhs.header.timestamp && 48 this->header.sequenceNumber == rhs.header.sequenceNumber && 49 this->primary == rhs.primary && 50 this->sync_packet == rhs.sync_packet); 51 } 52 bool operator!=(const Packet& rhs) const { return !operator==(rhs); } 53 bool operator<(const Packet& rhs) const { 54 if (this->header.timestamp == rhs.header.timestamp) { 55 if (this->header.sequenceNumber == rhs.header.sequenceNumber) { 56 // Timestamp and sequence numbers are identical. A sync packet should 57 // be recognized "larger" (i.e. "later") compared to a "network packet" 58 // (regular packet from network not sync-packet). If none of the packets 59 // are sync-packets, then deem the left hand side to be "smaller" 60 // (i.e., "earlier") if it is primary, and right hand side is not. 61 // 62 // The condition on sync packets to be larger than "network packets," 63 // given same RTP sequence number and timestamp, guarantees that a 64 // "network packet" to be inserted in an earlier position into 65 // |packet_buffer_| compared to a sync packet of same timestamp and 66 // sequence number. 67 if (rhs.sync_packet) 68 return true; 69 if (this->sync_packet) 70 return false; 71 return (this->primary && !rhs.primary); 72 } 73 return (static_cast<uint16_t>(rhs.header.sequenceNumber 74 - this->header.sequenceNumber) < 0xFFFF / 2); 75 } 76 return (static_cast<uint32_t>(rhs.header.timestamp 77 - this->header.timestamp) < 0xFFFFFFFF / 2); 78 } 79 bool operator>(const Packet& rhs) const { return rhs.operator<(*this); } 80 bool operator<=(const Packet& rhs) const { return !operator>(rhs); } 81 bool operator>=(const Packet& rhs) const { return !operator<(rhs); } 82 }; 83 84 // A list of packets. 85 typedef std::list<Packet*> PacketList; 86 87 } // namespace webrtc 88 #endif // WEBRTC_MODULES_AUDIO_CODING_NETEQ_PACKET_H_ 89
