Implementation for rtcp sender report

src/rtcp/rtcp_header.cpp

@@ -0,0 +1,20 @@
+#include "rtcp_header.h"
+
+RtcpHeader::RtcpHeader()
+    : version_(0), padding_(0), count_or_format_(0), length_(0) {}
+
+RtcpHeader::~RtcpHeader() {}
+
+int RtcpHeader::Encode(uint8_t version, uint8_t padding,
+                       uint8_t count_or_format, uint8_t payload_type,
+                       uint16_t length, uint8_t* buffer) {
+  if (!buffer) {
+    return 0;
+  }
+
+  buffer[0] = (version << 6) | (padding << 5) | (count_or_format << 4);
+  buffer[1] = payload_type;
+  buffer[2] = length >> 8 & 0xFF;
+  buffer[3] = length & 0xFF;
+  return 4;
+}