flexfec_sender.h (3820B)
1 /* 2 * Copyright (c) 2016 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 MODULES_RTP_RTCP_INCLUDE_FLEXFEC_SENDER_H_ 12 #define MODULES_RTP_RTCP_INCLUDE_FLEXFEC_SENDER_H_ 13 14 #include <cstddef> 15 #include <cstdint> 16 #include <memory> 17 #include <optional> 18 #include <string> 19 #include <vector> 20 21 #include "absl/strings/string_view.h" 22 #include "api/array_view.h" 23 #include "api/environment/environment.h" 24 #include "api/rtp_parameters.h" 25 #include "api/units/data_rate.h" 26 #include "api/units/timestamp.h" 27 #include "modules/include/module_fec_types.h" 28 #include "modules/rtp_rtcp/include/rtp_header_extension_map.h" 29 #include "modules/rtp_rtcp/include/rtp_rtcp_defines.h" 30 #include "modules/rtp_rtcp/source/rtp_header_extension_size.h" 31 #include "modules/rtp_rtcp/source/ulpfec_generator.h" 32 #include "modules/rtp_rtcp/source/video_fec_generator.h" 33 #include "rtc_base/bitrate_tracker.h" 34 #include "rtc_base/random.h" 35 #include "rtc_base/synchronization/mutex.h" 36 #include "rtc_base/thread_annotations.h" 37 38 namespace webrtc { 39 40 class RtpPacketToSend; 41 42 // Note that this class is not thread safe, and thus requires external 43 // synchronization. Currently, this is done using the lock in PayloadRouter. 44 45 class FlexfecSender : public VideoFecGenerator { 46 public: 47 FlexfecSender(const Environment& env, 48 int payload_type, 49 uint32_t ssrc, 50 uint32_t protected_media_ssrc, 51 absl::string_view mid, 52 const std::vector<RtpExtension>& rtp_header_extensions, 53 ArrayView<const RtpExtensionSize> extension_sizes, 54 const RtpState* rtp_state); 55 ~FlexfecSender(); 56 57 FecType GetFecType() const override { 58 return VideoFecGenerator::FecType::kFlexFec; 59 } 60 std::optional<uint32_t> FecSsrc() override { return ssrc_; } 61 62 // Sets the FEC rate, max frames sent before FEC packets are sent, 63 // and what type of generator matrices are used. 64 void SetProtectionParameters(const FecProtectionParams& delta_params, 65 const FecProtectionParams& key_params) override; 66 67 // Adds a media packet to the internal buffer. When enough media packets 68 // have been added, the FEC packets are generated and stored internally. 69 // These FEC packets are then obtained by calling GetFecPackets(). 70 void AddPacketAndGenerateFec(const RtpPacketToSend& packet) override; 71 72 // Returns generated FlexFEC packets. 73 std::vector<std::unique_ptr<RtpPacketToSend>> GetFecPackets() override; 74 75 // Returns the overhead, per packet, for FlexFEC. 76 size_t MaxPacketOverhead() const override; 77 78 DataRate CurrentFecRate() const override; 79 80 // Only called on the VideoSendStream queue, after operation has shut down. 81 std::optional<RtpState> GetRtpState() override; 82 83 private: 84 // Utility. 85 const Environment env_; 86 Random random_; 87 Timestamp last_generated_packet_ = Timestamp::MinusInfinity(); 88 89 // Config. 90 const int payload_type_; 91 const uint32_t timestamp_offset_; 92 const uint32_t ssrc_; 93 const uint32_t protected_media_ssrc_; 94 // MID value to send in the MID header extension. 95 const std::string mid_; 96 // Sequence number of next packet to generate. 97 uint16_t seq_num_; 98 99 // Implementation. 100 UlpfecGenerator ulpfec_generator_; 101 const RtpHeaderExtensionMap rtp_header_extension_map_; 102 const size_t header_extensions_size_; 103 104 mutable Mutex mutex_; 105 BitrateTracker fec_bitrate_ RTC_GUARDED_BY(mutex_); 106 }; 107 108 } // namespace webrtc 109 110 #endif // MODULES_RTP_RTCP_INCLUDE_FLEXFEC_SENDER_H_