防止时间戳回滚

src/MediaFile/Stamp.cpp

@@ -28,51 +28,51 @@
 
 namespace mediakit {
 
-void Stamp::revise(uint32_t dts, uint32_t pts, int64_t &dts_out, int64_t &pts_out) {
+int64_t DeltaStamp::deltaStamp(int64_t stamp) {
-    if(!pts){
+    if(!_last_stamp){
-        //没有播放时间戳,使其赋值为解码时间戳
+        //第一次计算时间戳增量,时间戳增量为0
+        _last_stamp = stamp;
+        return 0;
+    }
+
+    int64_t ret = stamp - _last_stamp;
+    if(ret >= 0){
+        //时间戳增量为正，返回之
+        _last_stamp = stamp;
+        return ret;
+    }
+
+    //时间戳增量为负，说明时间戳回环了或回退了
+    _last_stamp = stamp;
+    return _playback ? ret : 0;
+}
+
+void DeltaStamp::setPlayBack(bool playback) {
+    _playback = playback;
+}
+
+void Stamp::revise(int64_t dts, int64_t pts, int64_t &dts_out, int64_t &pts_out) {
+    if(!dts && !pts){
+        //没有时间戳，我们生成时间戳
+        pts = dts = _ticker.elapsedTime();
+    }else if(!pts){
+        //只是没有播放时间戳,使其赋值为解码时间戳
         pts = dts;
     }
+
     //pts和dts的差值
     int pts_dts_diff = pts - dts;
 
-    if(_first){
-        //记录第一次时间戳，后面好计算时间戳增量
-        _start_dts = dts;
-        _first = false;
-        _ticker.resetTime();
-    }
-    if (!dts) {
-        //没有解码时间戳，我们生成解码时间戳
-        dts = _ticker.elapsedTime();
-    }
-
     //相对时间戳
-    dts_out = dts - _start_dts;
+    _relativeStamp += deltaStamp(dts);
-    if(!_playback){
+    dts_out = _relativeStamp;
-        if(dts_out < _dts_inc){
-            //本次相对时间戳竟然小于上次？
-            if(dts_out < 0 || _dts_inc - dts_out > 0xFFFF){
-                //时间戳回环,保证下次相对时间戳与本次相对合理增长
-                _start_dts = dts - _dts_inc;
-                //本次时间戳强制等于上次时间戳
-                dts_out = _dts_inc;
-            }else{
-                //时间戳变小了？,那么取上次时间戳
-                dts_out = _dts_inc;
-            }
-        }
-    }
-
-
-    //保留这次相对时间戳，以便下次对比是否回环或乱序
-    _dts_inc = dts_out;
 
     //////////////以下是播放时间戳的计算//////////////////
     if(pts_dts_diff > 200 || pts_dts_diff < -200){
         //如果差值大于200毫秒，则认为由于回环导致时间戳错乱了
         pts_dts_diff = 0;
     }
+
     pts_out = dts_out + pts_dts_diff;
     if(pts_out < 0){
         //时间戳不能小于0
@@ -80,8 +80,13 @@ void Stamp::revise(uint32_t dts, uint32_t pts, int64_t &dts_out, int64_t &pts_ou
     }
 }
 
-void Stamp::setPlayBack(bool playback) {
+void Stamp::setRelativeStamp(int64_t relativeStamp) {
-    _playback = playback;
+    _relativeStamp = relativeStamp;
 }
 
+int64_t Stamp::getRelativeStamp() const {
+    return _relativeStamp;
+}
+
+
 }//namespace mediakit

src/MediaFile/Stamp.h

@@ -33,18 +33,33 @@ using namespace toolkit;
 
 namespace mediakit {
 
-//该类解决时间戳回环、回退问题
+class DeltaStamp{
-//计算相对时间戳或者产生平滑时间戳
-class Stamp {
 public:
-    Stamp() = default;
+    DeltaStamp() = default;
-    ~Stamp() = default;
+    ~DeltaStamp() = default;
 
     /**
-     * 设置回放模式，回放模式时间戳可以回退
+     * 计算时间戳增量
+     * @param stamp 绝对时间戳
+     * @return 时间戳增量
+     */
+    int64_t deltaStamp(int64_t stamp);
+
+    /**
+     * 设置是否为回放模式，回放模式运行时间戳回退
      * @param playback 是否为回放模式
      */
     void setPlayBack(bool playback = true);
+private:
+    int64_t _last_stamp = 0;
+    bool _playback = false;
+};
+//该类解决时间戳回环、回退问题
+//计算相对时间戳或者产生平滑时间戳
+class Stamp : public DeltaStamp{
+public:
+    Stamp() = default;
+    ~Stamp() = default;
 
     /**
      * 修正时间戳
@@ -53,12 +68,21 @@ public:
      * @param dts_out 输出dts
      * @param pts_out 输出pts
      */
-    void revise(uint32_t dts, uint32_t pts, int64_t &dts_out, int64_t &pts_out);
+    void revise(int64_t dts, int64_t pts, int64_t &dts_out, int64_t &pts_out);
+
+    /**
+     * 再设置相对时间戳，用于seek用
+     * @param relativeStamp 相对时间戳
+     */
+    void setRelativeStamp(int64_t relativeStamp);
+
+    /**
+     * 获取当前相对时间戳
+     * @return
+     */
+    int64_t getRelativeStamp() const ;
 private:
-    bool _playback = false;
+    int64_t _relativeStamp = 0;
-    int64_t _start_dts = 0;
-    int64_t _dts_inc = 0;
-    bool _first = true;
     SmoothTicker _ticker;
 };
 

src/Rtsp/RtspPlayer.cpp

@@ -68,12 +68,9 @@ void RtspPlayer::teardown(){
     CLEAR_ARR(_aui64RtpRecv)
     CLEAR_ARR(_aui64RtpRecv)
     CLEAR_ARR(_aui16NowSeq)
-	CLEAR_ARR(_aiFistStamp);
-	CLEAR_ARR(_aiNowStamp);
 
-    _pPlayTimer.reset();
+	_pPlayTimer.reset();
     _pRtpTimer.reset();
-    _iSeekTo = 0;
 	_uiCseq = 1;
 	_onHandshake = nullptr;
 }
@@ -222,6 +219,16 @@ void RtspPlayer::handleResDESCRIBE(const Parser& parser) {
 	SdpParser sdpParser(parser.Content());
 	//解析sdp
 	_aTrackInfo = sdpParser.getAvailableTrack();
+	auto title = sdpParser.getTrack(TrackTitle);
+	bool isPlayback = false;
+	if(title && title->_duration ){
+        isPlayback = true;
+	}
+
+    for(auto &stamp : _stamp){
+        stamp.setPlayBack(isPlayback);
+        stamp.setRelativeStamp(0);
+    }
 
 	if (_aTrackInfo.empty()) {
 		throw std::runtime_error("无有效的Sdp Track");
@@ -386,7 +393,7 @@ void RtspPlayer::handleResSETUP(const Parser &parser, unsigned int uiTrackIndex)
 	}
 	//所有setup命令发送完毕
 	//发送play命令
-	pause(false);
+    sendPause(false, 0,false);
 }
 
 void RtspPlayer::sendOptions() {
@@ -403,25 +410,19 @@ void RtspPlayer::sendDescribe() {
 }
 
 
-void RtspPlayer::sendPause(bool bPause,uint32_t seekMS){
+void RtspPlayer::sendPause(bool bPause,uint32_t seekMS,bool range){
-    if(!bPause){
-        //修改时间轴
-        int iTimeInc = seekMS - getProgressMilliSecond();
-        for(unsigned int i = 0 ;i < _aTrackInfo.size() ;i++){
-			_aiFistStamp[i] = _aiNowStamp[i] + iTimeInc;
-            _aiNowStamp[i] = _aiFistStamp[i];
-        }
-        _iSeekTo = seekMS;
-    }
-
 	//开启或暂停rtsp
 	_onHandshake = std::bind(&RtspPlayer::handleResPAUSE,this, placeholders::_1,bPause);
-	sendRtspRequest(bPause ? "PAUSE" : "PLAY",
+	if(!bPause && range){
-					_strContentBase,
+        sendRtspRequest(bPause ? "PAUSE" : "PLAY", _strContentBase,
-					{"Range",StrPrinter << "npt=" << setiosflags(ios::fixed) << setprecision(2) << seekMS / 1000.0 << "-"});
+                         {"Range",StrPrinter << "npt=" << setiosflags(ios::fixed) << setprecision(2) << seekMS / 1000.0 << "-"});
+    } else{
+        sendRtspRequest(bPause ? "PAUSE" : "PLAY", _strContentBase);
+    }
+
 }
 void RtspPlayer::pause(bool bPause) {
-    sendPause(bPause, getProgressMilliSecond());
+    sendPause(bPause, getProgressMilliSecond(),false);
 }
 
 void RtspPlayer::handleResPAUSE(const Parser& parser, bool bPause) {
@@ -430,6 +431,7 @@ void RtspPlayer::handleResPAUSE(const Parser& parser, bool bPause) {
 		return;
 	}
 	if (!bPause) {
+		uint32_t iSeekTo = 0;
         //修正时间轴
         auto strRange = parser["Range"];
         if (strRange.size()) {
@@ -437,25 +439,12 @@ void RtspPlayer::handleResPAUSE(const Parser& parser, bool bPause) {
             if (strStart == "now") {
                 strStart = "0";
             }
-            _iSeekTo = 1000 * atof(strStart.data());
+			iSeekTo = 1000 * atof(strStart.data());
-            DebugL << "seekTo(ms):" << _iSeekTo ;
+            DebugL << "seekTo(ms):" << iSeekTo ;
-        }
-        auto strRtpInfo =  parser["RTP-Info"];
-        if (strRtpInfo.size()) {
-            strRtpInfo.append(",");
-            vector<string> vec = split(strRtpInfo, ",");
-            for(auto &strTrack : vec){
-                strTrack.append(";");
-                auto strControlSuffix = strTrack.substr(1 + strTrack.rfind('/'),strTrack.find(';') - strTrack.rfind('/') - 1);
-                auto strRtpTime = FindField(strTrack.data(), "rtptime=", ";");
-                auto idx = getTrackIndexByControlSuffix(strControlSuffix);
-                if(idx != -1){
-                    _aiFistStamp[idx] = _aTrackInfo[idx]->_samplerate>0?atoll(strRtpTime.data()) * 1000 / _aTrackInfo[idx]->_samplerate :1;
-                    _aiNowStamp[idx] = _aiFistStamp[idx];
-                    DebugL << "rtptime(ms):" << strControlSuffix <<" " << strRtpTime;
-                }
-            }
         }
+		//设置相对时间戳
+		_stamp[0].setRelativeStamp(iSeekTo);
+		_stamp[1].setRelativeStamp(iSeekTo);
 		onPlayResult_l(SockException(Err_success, "rtsp play success"));
 	} else {
 		_pRtpTimer.reset();
@@ -630,12 +619,11 @@ void RtspPlayer::onRtpSorted(const RtpPacket::Ptr &rtppt, int trackidx){
 	}
 	_aui64RtpRecv[trackidx] ++;
 	_aui16NowSeq[trackidx] = rtppt->sequence;
-	_aiNowStamp[trackidx] = rtppt->timeStamp;
-	if( _aiFistStamp[trackidx] == 0){
-		_aiFistStamp[trackidx] = _aiNowStamp[trackidx];
-	}
 
-    rtppt->timeStamp -= _aiFistStamp[trackidx];
+	//计算相对时间戳
+	int64_t dts_out;
+	_stamp[trackidx].revise(rtppt->timeStamp,rtppt->timeStamp,dts_out,dts_out);
+    rtppt->timeStamp = dts_out;
 	onRecvRTP_l(rtppt,_aTrackInfo[trackidx]);
 }
 float RtspPlayer::getPacketLossRate(TrackType type) const{
@@ -653,7 +641,6 @@ float RtspPlayer::getPacketLossRate(TrackType type) const{
 		return 1.0 - (double)totalRecv / totalSend;
 	}
 
-
 	if(_aui16NowSeq[iTrackIdx] - _aui16FirstSeq[iTrackIdx] + 1 == 0){
 		return 0;
 	}
@@ -661,14 +648,10 @@ float RtspPlayer::getPacketLossRate(TrackType type) const{
 }
 
 uint32_t RtspPlayer::getProgressMilliSecond() const{
-	uint32_t iTime[2] = {0,0};
+    return MAX(_stamp[0].getRelativeStamp(),_stamp[1].getRelativeStamp());
-    for(unsigned int i = 0 ;i < _aTrackInfo.size() ;i++){
-		iTime[i] = _aiNowStamp[i] - _aiFistStamp[i];
-    }
-    return _iSeekTo + MAX(iTime[0],iTime[1]);
 }
 void RtspPlayer::seekToMilliSecond(uint32_t ms) {
-    sendPause(false,ms);
+    sendPause(false,ms, true);
 }
 
 void RtspPlayer::sendRtspRequest(const string &cmd, const string &url, const std::initializer_list<string> &header) {

src/Rtsp/RtspPlayer.h

@@ -40,6 +40,7 @@
 #include "Network/TcpClient.h"
 #include "RtspSplitter.h"
 #include "RtpReceiver.h"
+#include "MediaFile/Stamp.h"
 
 using namespace std;
 using namespace toolkit;
@@ -114,7 +115,7 @@ private:
 
 	//发送SETUP命令
 	void sendSetup(unsigned int uiTrackIndex);
-	void sendPause(bool bPause,uint32_t ms);
+	void sendPause(bool bPause,uint32_t ms, bool range);
 	void sendOptions();
 	void sendDescribe();
 
@@ -148,12 +149,8 @@ private:
 	std::shared_ptr<Timer> _pPlayTimer;
 	std::shared_ptr<Timer> _pRtpTimer;
 
-    //播放进度控制,单位毫秒
+	//时间戳
-    uint32_t _iSeekTo = 0;
+	Stamp _stamp[2];
-
-    //单位毫秒
-	uint32_t _aiFistStamp[2] = {0,0};
-	uint32_t _aiNowStamp[2] = {0,0};
 
 	//rtcp相关
     RtcpCounter _aRtcpCnt[2]; //rtcp统计,trackid idx 为数组下标