[feat] update congestion control feedback

src/qos/congestion_control_feedback_tracker.h

@@ -0,0 +1,43 @@
+/*
+ * @Author: DI JUNKUN
+ * @Date: 2024-12-18
+ * Copyright (c) 2024 by DI JUNKUN, All Rights Reserved.
+ */
+
+#ifndef _CONGESTION_CONTROL_FEEDBACK_TRACKER_H_
+#define _CONGESTION_CONTROL_FEEDBACK_TRACKER_H_
+
+#include <optional>
+#include <vector>
+
+#include "rtp_packet_received.h"
+
+class CongestionControlFeedbackTracker {
+ public:
+  CongestionControlFeedbackTracker() = default;
+
+  void ReceivedPacket(const RtpPacketReceived& packet);
+
+  // Adds received packets to `packet_feedback`
+  // RTP sequence numbers are continous from the last created feedback unless
+  // reordering has occured between feedback packets. If so, the sequence
+  // number range may overlap with previousely sent feedback.
+  void AddPacketsToFeedback(
+      int64_t feedback_time,
+      std::vector<CongestionControlFeedback::PacketInfo>& packet_feedback);
+
+ private:
+  struct PacketInfo {
+    uint32_t ssrc;
+    int64_t unwrapped_sequence_number = 0;
+    int64_t arrival_time;
+    rtc::EcnMarking ecn = rtc::EcnMarking::kNotEct;
+  };
+
+  std::optional<int64_t> last_sequence_number_in_feedback_;
+  SeqNumUnwrapper<uint16_t> unwrapper_;
+
+  std::vector<PacketInfo> packets_;
+};
+
+#endif