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头文件

#ifndef PORTAUDIORECORDER_H#define PORTAUDIORECORDER_H//通过PortAudio录音的类.//这个类特别之处是维护设备热插拔和热更替,提供缺数据(比如蓝牙话筒关话筒)解决方案//当开始后,没有录音设备,将提供最多5分钟的静音录制,如果及时接入设备,能够正常录音;//如果不提供设备5分钟后则整体放弃.//如果设备中途断开,则持续提供静音录制.力保时间同步性.#include "portaudio/portaudio.h"#include 
    
     #include 
     
      class ISinkForPA{public:    enum ErrorType{        ETStreamOpen,    //流打开,代表正常工作.        ETError,         //发生中断,可能是设备断连,可以重插或等待        ETNoDevice,    };    //常规数据处理    virtual bool tPaHandle(const void *input,unsigned long frameCount)=0;    //宣布放弃处理, 设计为一段时间都没有设备或不正常.    virtual void tPaNotice(ErrorType et)=0; //发生故障,time是遗失的时间.如果要继续需要补相应时间的空白.    //需要补足0数据    virtual void tPaNeedPad(double time)=0; //需要补上这么多时间的空数据,否则时间长度不对.(蓝牙话筒关话筒的时候出现!)};//这个类没有做成单例,但是按单例来实现.class PortAudioRecord{public:    PortAudioRecord(ISinkForPA *cb);    ~PortAudioRecord();    void set(int sampleRate, int framePerBuffer);    int defaultInputDevice();    //除非初始化失败,否则都是成功(哪怕没设备)    bool start();    void stop();public:    static int PACallback(            const void *input, void *output,            unsigned long frameCount,            const PaStreamCallbackTimeInfo* timeInfo,            PaStreamCallbackFlags statusFlags,            void *userData );    int dataCallBack(            const void *input,            unsigned long frameCount,            const PaStreamCallbackTimeInfo* timeInfo,            PaStreamCallbackFlags statusFlags);protected:    bool openStream();    void closeStream();    void checkDataFeed();private:    ISinkForPA *cb_;    PaStream *paStream_;    QElapsedTimer etimer_;    QTimer chktimer_;    qint64 feedTime_; //已经喂饱数据的时间,以etimer_参照.    double lastDacTime_;  //最后一次提供数据的portaudio时间.注意起始时间是不确定的.(小于0代表未知.)    int deviceIdx_;    int sampleRate_;    int framePerBuffer_;    volatile bool haltFlag_; //pa录制异常的标记.};#endif // PORTAUDIORECORDER_H
     
    

cpp文件

#include "PortAudioRecord.h"#include 
    
     //说明:input是从设备读到的数据,字节长度是frameCount*sizeof(SAMPLE)//如果要echo,需要在初始化的时候指定好设备,把input拷到output即可.//#define NODEVICEGIVEUP (5*60*1000) //无设备放弃时间.//定义pa的sample类型为int16,这个可以配合webrtc模块#define PA_SAMPLE_TYPE paInt16//对应的sample单位是short,占2字节.typedef short SAMPLE;class PaInitMana{public:    PaInitMana():initOK(false){}    bool set()  { if(!initOK) initOK = (paNoError == Pa_Initialize()); return initOK;  }    bool reset(){ if(initOK) unset(); return set();  }    void unset(){ if(initOK) Pa_Terminate();  initOK = false; }    operator bool(){ return initOK; }private:    bool initOK;} gPaInit;PortAudioRecord::PortAudioRecord(ISinkForPA *cb)    : cb_(NULL)    , paStream_(NULL)    , feedTime_(0)    , lastDacTime_(-1.0) //小于0代表未知.    , deviceIdx_(paNoDevice)    , sampleRate_    (32000)    , framePerBuffer_(6400)    , haltFlag_(false){    Q_ASSERT(cb);    cb_ = cb;    chktimer_.setInterval(500);    chktimer_.setSingleShot(false);    QObject::connect(&chktimer_,&QTimer::timeout,[=](){        //检查数据缺失, 或者没设备导致的数据缺失.        checkDataFeed();    });    chktimer_.start();}PortAudioRecord::~PortAudioRecord(){    this->stop();}void PortAudioRecord::set(int sampleRate, int framePerBuffer){    sampleRate_ = sampleRate;    framePerBuffer_ = framePerBuffer;}bool PortAudioRecord::start(){    qInfo()<<"Pa_start";    etimer_.start();    if(!gPaInit.set())return false;    lastDacTime_ = -1.0;    Q_ASSERT(deviceIdx_==paNoDevice);    deviceIdx_ = defaultInputDevice();    if(deviceIdx_ != paNoDevice)    {        PaError err;        if(openStream()==false){            paStream_ = NULL;            deviceIdx_ = paNoDevice;            goto start_end;        }        err = Pa_StartStream( paStream_ );        qInfo()<<"Pa_StartStream"<
     
      tPaNotice(ISinkForPA::ETStreamOpen);        return true;    }start_end:    if(deviceIdx_ == paNoDevice)    {        cb_->tPaNotice(ISinkForPA::ETNoDevice);        gPaInit.unset();    }    return true;}void PortAudioRecord::stop(){    qInfo()<<"Pa_stop";    chktimer_.stop();    if(paStream_){        closeStream();    }    gPaInit.unset();}int PortAudioRecord::dataCallBack(        const void *input,        unsigned long frameCount,        const PaStreamCallbackTimeInfo *timeInfo,        PaStreamCallbackFlags statusFlags){    if(statusFlags==0)    {        lastDacTime_ = timeInfo->currentTime;        bool rt = cb_->tPaHandle(input,frameCount);        feedTime_ = etimer_.elapsed();        return rt?paContinue:paComplete;    }    else    {        qInfo()<<"PACallback statusFlags:"<
      
       <<"Abort!";        haltFlag_ = true;        return paAbort;    }}bool PortAudioRecord::openStream(){    Q_ASSERT(gPaInit);    if(!gPaInit) return false;    PaError err;    PaStreamParameters inputDev;    inputDev.device = deviceIdx_; //Pa_GetDefaultInputDevice();    inputDev.channelCount = 1;    inputDev.sampleFormat = PA_SAMPLE_TYPE;    inputDev.suggestedLatency = 1;    inputDev.hostApiSpecificStreamInfo = NULL;    PaStreamParameters outputDev;    outputDev.device = Pa_GetDefaultOutputDevice(); //paNoDevice;  //Pa_GetDefaultOutputDevice();    outputDev.channelCount = 1;    outputDev.sampleFormat = PA_SAMPLE_TYPE;    outputDev.suggestedLatency = 1;    outputDev.hostApiSpecificStreamInfo = NULL;    err = Pa_OpenStream(                &paStream_,                &inputDev,                &outputDev,                sampleRate_,                framePerBuffer_, /* frames per buffer */                paDitherOff,    /* paDitherOff, // flags */                PortAudioRecord::PACallback,                this);    qInfo()<<"openStream"<
       
        dataCallBack(input,frameCount,timeInfo,statusFlags);}void PortAudioRecord::checkDataFeed(){    if(haltFlag_)    {        if(paStream_){            PaError err;            err = Pa_CloseStream( paStream_ );            qDebug()<<"Pa_CloseStream:"<
        
         tPaNotice(ISinkForPA::ETError);    }    if(paStream_ == NULL)    {   //枚举设备,处理热插拔.        if(gPaInit.set())        {            int didx = defaultInputDevice();            if(didx != deviceIdx_)            {                qInfo()<<"Pa_device changed!"<
         
          <<"->"<
          
           tPaNotice(ISinkForPA::ETStreamOpen); qInfo()<<"Pa_startStream2 succ!"; } } } if(paStream_==NULL) {//如果不成功,继续释放Pa gPaInit.unset(); } } } qint64 tnow = etimer_.elapsed(); //检查数据喂养情况,如果有较大出入,补静音. qint64 feedGap = tnow-feedTime_; if(feedGap>0 && feedGap > 1000) { if(deviceIdx_==paNoDevice) { //如果没有录音设备,直接补静音// if(lastDacTime_ >0 && tnow > NODEVICEGIVEUP)// { //太久了,放弃本次录音. 只针对从来没录过音的情况.// cb_->tPaNotice(ISinkForPA::ETHalt);// }// else { cb_->tPaNeedPad((double)(feedGap)/1000); feedTime_ = tnow; } } else { if(lastDacTime_<=0) { //如果没有来过有效数据,补静音 cb_->tPaNeedPad((double)(feedGap)/1000); feedTime_ = tnow; } else { //来过有效数据,补到当前时间之前. Q_ASSERT(paStream_); double unit = (double)framePerBuffer_/sampleRate_; double dnow = Pa_GetStreamTime(paStream_); qDebug()<<"dnow"<
           
            <<"lastDacTime_"<
            
             0); Q_ASSERT(gap*1000
             
              0){ cb_->tPaNeedPad(gap); lastDacTime_ += gap; //dnow-unit; feedTime_ += qint64(gap*1000); } } } }}int PortAudioRecord::defaultInputDevice(){ //注意,经过试验,如果不调用Pa_Terminate,Pa_GetDefaultInputDevice的结果不会变化. //如果没有调用Pa_Terminate,Pa_Initialize也不能刷新DefaultInputDevice. if(!gPaInit) return paNoDevice; return Pa_GetDefaultInputDevice();}
             
            
           
          
         
        
       
      
     
    

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