[feat] congestion control feedback sending support

src/rtcp/rtcp_sender/rtcp_sender.h

@@ -0,0 +1,53 @@
+/*
+ * @Author: DI JUNKUN
+ * @Date: 2025-01-10
+ * Copyright (c) 2025 by DI JUNKUN, All Rights Reserved.
+ */
+
+#ifndef _RTCP_SENDER_H_
+#define _RTCP_SENDER_H_
+
+#define IP_PACKET_SIZE 1500
+
+#include <functional>
+#include <vector>
+
+#include "log.h"
+
+class RTCPSender {
+ public:
+  RTCPSender(std::function<int(const uint8_t*, size_t)> callback,
+             size_t max_packet_size)
+      : callback_(callback), max_packet_size_(max_packet_size) {
+    if (max_packet_size > IP_PACKET_SIZE) {
+      LOG_ERROR("max_packet_size must be less than IP_PACKET_SIZE");
+    }
+  }
+  ~RTCPSender() {
+    if (index_ == 0) {
+      LOG_ERROR("Unsent rtcp packet");
+    }
+  }
+
+  // Appends a packet to pending compound packet.
+  // Sends rtcp packet if buffer is full and resets the buffer.
+  void AppendPacket(const RtcpPacket& packet) {
+    packet.Create(buffer_, &index_, max_packet_size_, callback_);
+  }
+
+  // Sends pending rtcp packet.
+  void Send() {
+    if (index_ > 0 && callback_) {
+      callback_(buffer_, index_);
+      index_ = 0;
+    }
+  }
+
+ private:
+  std::function<int(const uint8_t*, size_t)> callback_ = nullptr;
+  const size_t max_packet_size_;
+  size_t index_ = 0;
+  uint8_t buffer_[IP_PACKET_SIZE];
+};
+
+#endif