1 /* 2 * Copyright (c) 2015 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_RTP_RTCP_SOURCE_RTCP_PACKET_TRANSPORT_FEEDBACK_H_ 12 #define WEBRTC_MODULES_RTP_RTCP_SOURCE_RTCP_PACKET_TRANSPORT_FEEDBACK_H_ 13 14 #include <deque> 15 #include <vector> 16 17 #include "webrtc/base/constructormagic.h" 18 #include "webrtc/modules/include/module_common_types.h" 19 #include "webrtc/modules/rtp_rtcp/source/rtcp_packet.h" 20 21 namespace webrtc { 22 namespace rtcp { 23 24 class PacketStatusChunk; 25 26 class TransportFeedback : public RtcpPacket { 27 public: 28 TransportFeedback(); 29 virtual ~TransportFeedback(); 30 31 void WithPacketSenderSsrc(uint32_t ssrc); 32 void WithMediaSourceSsrc(uint32_t ssrc); 33 void WithBase(uint16_t base_sequence, // Seq# of first packet in this msg. 34 int64_t ref_timestamp_us); // Reference timestamp for this msg. 35 void WithFeedbackSequenceNumber(uint8_t feedback_sequence); 36 // NOTE: This method requires increasing sequence numbers (excepting wraps). 37 bool WithReceivedPacket(uint16_t sequence_number, int64_t timestamp_us); 38 39 enum class StatusSymbol { 40 kNotReceived, 41 kReceivedSmallDelta, 42 kReceivedLargeDelta, 43 }; 44 45 uint16_t GetBaseSequence() const; 46 std::vector<TransportFeedback::StatusSymbol> GetStatusVector() const; 47 std::vector<int16_t> GetReceiveDeltas() const; 48 49 // Get the reference time in microseconds, including any precision loss. 50 int64_t GetBaseTimeUs() const; 51 // Convenience method for getting all deltas as microseconds. The first delta 52 // is relative the base time. 53 std::vector<int64_t> GetReceiveDeltasUs() const; 54 55 uint32_t GetPacketSenderSsrc() const; 56 uint32_t GetMediaSourceSsrc() const; 57 static const int kDeltaScaleFactor = 250; // Convert to multiples of 0.25ms. 58 static const uint8_t kFeedbackMessageType = 15; // TODO(sprang): IANA reg? 59 static const uint8_t kPayloadType = 205; // RTPFB, see RFC4585. 60 61 static rtc::scoped_ptr<TransportFeedback> ParseFrom(const uint8_t* buffer, 62 size_t length); 63 64 protected: 65 bool Create(uint8_t* packet, 66 size_t* position, 67 size_t max_length, 68 PacketReadyCallback* callback) const override; 69 70 size_t BlockLength() const override; 71 72 private: 73 static PacketStatusChunk* ParseChunk(const uint8_t* buffer, size_t max_size); 74 75 int64_t Unwrap(uint16_t sequence_number); 76 bool AddSymbol(StatusSymbol symbol, int64_t seq); 77 bool Encode(StatusSymbol symbol); 78 bool HandleRleCandidate(StatusSymbol symbol, 79 int current_capacity, 80 int delta_size); 81 void EmitRemaining(); 82 void EmitVectorChunk(); 83 void EmitRunLengthChunk(); 84 85 uint32_t packet_sender_ssrc_; 86 uint32_t media_source_ssrc_; 87 int32_t base_seq_; 88 int64_t base_time_; 89 uint8_t feedback_seq_; 90 std::vector<PacketStatusChunk*> status_chunks_; 91 std::vector<int16_t> receive_deltas_; 92 93 int64_t last_seq_; 94 int64_t last_timestamp_; 95 std::deque<StatusSymbol> symbol_vec_; 96 uint16_t first_symbol_cardinality_; 97 bool vec_needs_two_bit_symbols_; 98 uint32_t size_bytes_; 99 100 RTC_DISALLOW_COPY_AND_ASSIGN(TransportFeedback); 101 }; 102 103 } // namespace rtcp 104 } // namespace webrtc 105 #endif // WEBRTC_MODULES_RTP_RTCP_SOURCE_RTCP_PACKET_TRANSPORT_FEEDBACK_H_ 106