PortAudio 采用回调方式，这样可以一帧一帧的处理

头文件：

#ifndef __CAPTURE_AUDIO__
#define __CAPTURE_AUDIO__

#include <functional>
#include <windows.h>
#include "portaudio.h"

#define SAMPLE_RATE	44100

class CaptureAudio
{
public:
	CaptureAudio();
	~CaptureAudio();

public:
	bool Init(const std::function<void(unsigned char* pPcmAudioData, long nLen)>& pFunc);
	void Uninit();

private:
	static int Audio_Pcm_CB(const void* input, void* output, unsigned long frameCount, const PaStreamCallbackTimeInfo* timeInfo, PaStreamCallbackFlags statusFlags, void* userData);

private:
	static int m_nExiting;

private:
	PaStream* m_pAudioStream = nullptr;

private:
	static std::function<void(unsigned char* pPcmAudioData, long nLen)> m_pFunc;
};

#endif

源文件：

#include "CaptureAudio.h"

#include <chrono>
#include <thread>
#include <direct.h>

using namespace std;

int CaptureAudio::m_nExiting = 0;
std::function<void(unsigned char* pPcmAudioData, long nLen)> CaptureAudio::m_pFunc = nullptr;

CaptureAudio::CaptureAudio()
{

}
CaptureAudio::~CaptureAudio()
{

}

int CaptureAudio::Audio_Pcm_CB(const void* input, void* output, unsigned long frameCount, const PaStreamCallbackTimeInfo* timeInfo, PaStreamCallbackFlags statusFlags, void* userData)
{
	if (m_pFunc) {
		m_pFunc((unsigned char*)input, frameCount * 1 /*输入通道*/ * sizeof(short) /*16位bit, paInt16*/);
	}

	if (m_nExiting){
		return paComplete;
	}
	else {
		return paContinue;
	}
}

bool CaptureAudio::Init(const std::function<void(unsigned char* pPcmAudioData, long nLen)>& pFunc)
{
	PaError nErr = Pa_Initialize();
	if (nErr != paNoError) {
		return false;
	}
	PaStreamParameters inputParameters;
	inputParameters.device = Pa_GetDefaultInputDevice(); /* default input device */
	if (inputParameters.device == paNoDevice) {
		return false;
	}
	inputParameters.channelCount = 1;
	inputParameters.sampleFormat = paInt16;
	inputParameters.suggestedLatency = Pa_GetDeviceInfo(inputParameters.device)->defaultLowInputLatency;
	inputParameters.hostApiSpecificStreamInfo = NULL;
	nErr = Pa_OpenStream(
		&m_pAudioStream,
		&inputParameters,
		NULL,                  /* &outputParameters, */
		SAMPLE_RATE,
		SAMPLE_RATE / 1000 * 200,
		paClipOff,      /* we won't output out of range samples so don't bother clipping them */
		Audio_Pcm_CB, /* no callback, use blocking API */
		NULL); /* no callback, so no callback userData */
	if (nErr != paNoError) {
		return false;
	}

	//启动录音
	Pa_StartStream(m_pAudioStream);

	//
	m_pFunc = pFunc;
	return true;
}

void CaptureAudio::Uninit()
{
	m_nExiting = 1;

	Pa_CloseStream(m_pAudioStream);
	Pa_Terminate();
}

打开录制的pcm