优化frame性能及整理代码

src/Extension/G711.cpp

@@ -12,6 +12,47 @@
 
 namespace mediakit{
 
+/**
+ * G711类型SDP
+ */
+class G711Sdp : public Sdp {
+public:
+    /**
+     * G711采样率固定为8000
+     * @param codecId G711A G711U
+     * @param sample_rate 音频采样率
+     * @param payload_type rtp payload
+     * @param bitrate 比特率
+     */
+    G711Sdp(CodecId codecId,
+            int sample_rate,
+            int channels,
+            int bitrate = 128,
+            int payload_type = 98) : Sdp(sample_rate,payload_type), _codecId(codecId){
+        _printer << "m=audio 0 RTP/AVP " << payload_type << "\r\n";
+        if (bitrate) {
+            _printer << "b=AS:" << bitrate << "\r\n";
+        }
+        _printer << "a=rtpmap:" << payload_type << (codecId == CodecG711A ? " PCMA/" : " PCMU/") << sample_rate  << "/" << channels << "\r\n";
+        _printer << "a=control:trackID=" << (int)TrackAudio << "\r\n";
+    }
+
+    string getSdp() const override {
+        return _printer;
+    }
+
+    CodecId getCodecId() const override {
+        return _codecId;
+    }
+private:
+    _StrPrinter _printer;
+    CodecId _codecId;
+};
+
+Track::Ptr G711Track::clone() {
+    return std::make_shared<std::remove_reference<decltype(*this)>::type>(*this);
+}
+
 Sdp::Ptr G711Track::getSdp() {
     if(!ready()){
         WarnL << getCodecName() << " Track未准备好";