添加对g711A/U rtsp支持相关文件，api添加windows静态库编译选项，g711 RTMP支持尚未修改

src/Extension/G711.h

@@ -0,0 +1,248 @@
+/*
+ * Copyright (c) 2016 The ZLMediaKit project authors. All Rights Reserved.
+ *
+ * This file is part of ZLMediaKit(https://github.com/xiongziliang/ZLMediaKit).
+ *
+ * Use of this source code is governed by MIT license that can be found in the
+ * LICENSE file in the root of the source tree. All contributing project authors
+ * may be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef ZLMEDIAKIT_G711_H
+#define ZLMEDIAKIT_G711_H
+
+#include "Frame.h"
+#include "Track.h"
+
+namespace mediakit{
+
+class G711Frame;
+
+unsigned const samplingFrequencyTableG711[16] = { 96000, 88200,
+                                              64000, 48000,
+                                              44100, 32000,
+                                              24000, 22050,
+                                              16000, 12000,
+                                              11025, 8000,
+                                              7350, 0, 0, 0 };
+
+void	makeAdtsHeader(const string &strAudioCfg,G711Frame &adts);
+void 	writeAdtsHeader(const G711Frame &adts, uint8_t *pcAdts) ;
+string 	makeG711AdtsConfig(const uint8_t *pcAdts);
+void 	getAACInfo(const G711Frame &adts,int &iSampleRate,int &iChannel);
+
+
+/**
+ * aac帧，包含adts头
+ */
+class G711Frame : public Frame {
+public:
+    typedef std::shared_ptr<G711Frame> Ptr;
+
+    char *data() const override{
+        return (char *)buffer;
+    }
+    uint32_t size() const override {
+        return frameLength;
+    }
+    uint32_t dts() const override {
+        return timeStamp;
+    }
+    uint32_t prefixSize() const override{
+        return iPrefixSize;
+    }
+
+    TrackType getTrackType() const override{
+        return TrackAudio;
+    }
+
+    CodecId getCodecId() const override{
+        return CodecAAC;
+    }
+
+    bool keyFrame() const override {
+        return false;
+    }
+
+    bool configFrame() const override{
+        return false;
+    }
+public:
+    unsigned int frameLength; // 一个帧的长度包括 raw data block
+    unsigned char buffer[2 * 1024 + 7];
+    uint32_t timeStamp;
+    uint32_t iPrefixSize = 0;
+} ;
+
+class G711FrameNoCacheAble : public FrameNoCacheAble {
+public:
+    typedef std::shared_ptr<G711FrameNoCacheAble> Ptr;
+
+    G711FrameNoCacheAble(CodecId codecId, char *ptr,uint32_t size,uint32_t dts,int prefixeSize = 7){
+        _codecId = codecId;
+        _ptr = ptr;
+        _size = size;
+        _dts = dts;
+        _prefixSize = prefixeSize;
+    }
+
+    TrackType getTrackType() const override{
+        return TrackAudio;
+    }
+
+    CodecId getCodecId() const override{
+        return _codecId;
+    }
+
+    bool keyFrame() const override {
+        return false;
+    }
+
+    bool configFrame() const override{
+        return false;
+    }
+
+private:
+    CodecId _codecId;
+} ;
+
+
+/**
+ * g711音频通道
+ */
+class G711Track : public AudioTrack{
+public:
+    typedef std::shared_ptr<G711Track> Ptr;
+
+    /**
+     * 延后获取adts头信息
+     * 在随后的inputFrame中获取adts头信息
+     */
+    G711Track(){}
+
+    /**
+     * G711A G711U
+     */
+    G711Track(CodecId codecId, int sampleBit = 16, int sampleRate = 8000){
+        _codecid = codecId;
+        _sampleBit = sampleBit;
+        _sampleRate = sampleRate;
+        onReady();
+    }
+
+    /**
+     * 返回编码类型
+     * @return
+     */
+    CodecId getCodecId() const override{
+        return _codecid;
+    }
+
+    /**
+     * 在获取aac_cfg前是无效的Track
+     * @return
+     */
+    bool ready() override {
+        return true;
+    }
+
+
+    /**
+    * 返回音频采样率
+    * @return
+    */
+    int getAudioSampleRate() const override{
+        return _sampleRate;
+    }
+    /**
+     * 返回音频采样位数，一般为16或8
+     * @return
+     */
+    int getAudioSampleBit() const override{
+        return _sampleBit;
+    }
+    /**
+     * 返回音频通道数
+     * @return
+     */
+    int getAudioChannel() const override{
+        return _channel;
+    }
+
+    /**
+    * 输入数据帧,并获取aac_cfg
+    * @param frame 数据帧
+    */
+    void inputFrame(const Frame::Ptr &frame) override{
+        AudioTrack::inputFrame(frame);
+    }
+private:
+    /**
+     * 
+     */
+    void onReady(){
+/*
+        if(_cfg.size() < 2){
+            return;
+        }
+        G711Frame aacFrame;
+        makeAdtsHeader(_cfg,aacFrame);
+        getAACInfo(aacFrame,_sampleRate,_channel);*/
+    }
+    Track::Ptr clone() override {
+        return std::make_shared<std::remove_reference<decltype(*this)>::type >(*this);
+    }
+
+    //生成sdp
+    Sdp::Ptr getSdp() override ;
+private:
+    string _cfg;
+    CodecId _codecid = CodecG711A;
+    int _sampleRate = 8000;
+    int _sampleBit = 16;
+    int _channel = 1;
+};
+
+
+/**
+* aac类型SDP
+*/
+class G711Sdp : public Sdp {
+public:
+
+    /**
+     *
+     * @param aac_codecId G711A G711U
+     * @param sample_rate 音频采样率
+     * @param playload_type rtp playload type 默认0为G711U， 8为G711A
+     * @param bitrate 比特率
+     */
+    G711Sdp(CodecId codecId,
+           int sample_rate,
+           int playload_type = 0,
+           int bitrate = 128) : Sdp(sample_rate,playload_type), _codecId(codecId){
+        _printer << "m=audio 0 RTP/AVP " << playload_type << "\r\n";
+        //_printer << "b=AS:" << bitrate << "\r\n";
+        _printer << "a=rtpmap:" << playload_type << (codecId == CodecG711A ? " PCMA/" : " PCMU/") << sample_rate << "\r\n";
+        _printer << "a=control:trackID=" << getTrackType() << "\r\n";
+    }
+
+    string getSdp() const override {
+        return _printer;
+    }
+
+    TrackType getTrackType() const override {
+        return TrackAudio;
+    }
+    CodecId getCodecId() const override {
+        return _codecId;
+    }
+private:
+    _StrPrinter _printer;
+    CodecId _codecId = CodecG711A;
+};
+
+}//namespace mediakit
+
+
+#endif //ZLMEDIAKIT_AAC_H