基于WASAPI的音频捕获和音频播放，注意“禁用前面板插孔检测”。

http://blog.csdn.net/XscKernel/article/details/52204853#cpp
参照该博主的文章，再次感谢。

需要安装windows SDKs，还用到ksuser和Ole32两个库。

录音：

 #include <mmdeviceapi.h>
#include <Audioclient.h>
#include <windows.h>
#include <stdio.h>
#include <string.h>

#define REFTIMES_PER_SEC        10000000
#define REFTIMES_PER_MILLISEC   10000

#define EXIT_ON_ERROR(hres)  \
    if (FAILED(hres)) { goto Exit; }

#define SAFE_RELEASE(punk)  \
    if ((punk) != NULL) { (punk)->Release(); (punk) = NULL; }

const CLSID CLSID_MMDeviceEnumerator    = __uuidof(MMDeviceEnumerator);
const IID IID_IMMDeviceEnumerator       = __uuidof(IMMDeviceEnumerator);
const IID IID_IAudioClient              = __uuidof(IAudioClient);
const IID IID_IAudioCaptureClient       = __uuidof(IAudioCaptureClient);

FILE *fp = NULL;

class MyAudioSink {
public:
    int SetFormat(WAVEFORMATEX *pwfx);
    int CopyData(char *pData, UINT32 numFramesAvailable, BOOL *pbDone);
};

int MyAudioSink::SetFormat(WAVEFORMATEX *pwfx)
{
    FILE *fp = fopen("capture_format.txt", "w");
    char str[128];
    sprintf(str, "wFormatTag \t\tis %x\nnChannels \t\tis %d\nnSamplesPerSec \tis %ld\nnAvgBytesPerSec is %ld\nwBitsPerSample \tis %d",
            pwfx->wFormatTag, pwfx->nChannels, pwfx->nSamplesPerSec, pwfx->nAvgBytesPerSec, pwfx->wBitsPerSample);
    fwrite(str, 1, strlen(str), fp);
    fclose(fp);
    return 0;
}

int MyAudioSink::CopyData(char *pData, UINT32 numFramesAvailable, BOOL *pbDone)
{
    if(pData != NULL)
        fwrite(pData, numFramesAvailable, 1, fp);
    return 0;
}

// pwfx->nSamplesPerSec = 44100;
BOOL AdjustFormatTo16Bits(WAVEFORMATEX *pwfx)
{
    BOOL bRet(FALSE);
    if(pwfx->wFormatTag == WAVE_FORMAT_IEEE_FLOAT)
        pwfx->wFormatTag = WAVE_FORMAT_PCM;
    else if(pwfx->wFormatTag == WAVE_FORMAT_EXTENSIBLE)
    {
        PWAVEFORMATEXTENSIBLE pEx = reinterpret_cast<PWAVEFORMATEXTENSIBLE>(pwfx);
        if (IsEqualGUID(KSDATAFORMAT_SUBTYPE_IEEE_FLOAT, pEx->SubFormat))
        {
            pEx->SubFormat = KSDATAFORMAT_SUBTYPE_PCM;
            pEx->Samples.wValidBitsPerSample = 16;
        }
    }
    else
        return bRet;
    pwfx->wBitsPerSample = 16;
    pwfx->nBlockAlign = pwfx->nChannels * pwfx->wBitsPerSample / 8;
    pwfx->nAvgBytesPerSec = pwfx->nBlockAlign * pwfx->nSamplesPerSec;
    bRet = TRUE;
    return bRet;
}

HRESULT RecordAudioStream(MyAudioSink *pMySink)
{
    HRESULT         hr;
//    REFERENCE_TIME  hnsActualDuration;
    UINT32          bufferFrameCount;
    UINT32          numFramesAvailable;
    BYTE *          pData;
    DWORD           flags;
    REFERENCE_TIME  hnsDefaultDevicePeriod(0);

    IMMDeviceEnumerator *   pEnumerator             = NULL;
    IMMDevice *             pDevice                 = NULL;
    IAudioClient *          pAudioClient            = NULL;
    IAudioCaptureClient *   pCaptureClient          = NULL;
    WAVEFORMATEX *          pwfx                    = NULL;
    UINT32                  packetLength            = 0;
    BOOL                    bDone                   = FALSE;
    HANDLE                  hTimerWakeUp            = NULL;

    hr = CoCreateInstance(CLSID_MMDeviceEnumerator, NULL, CLSCTX_ALL, IID_IMMDeviceEnumerator, (void**)&pEnumerator);
    EXIT_ON_ERROR(hr)

    hr = pEnumerator->GetDefaultAudioEndpoint(eRender, eConsole, &pDevice);
    EXIT_ON_ERROR(hr)

    hr = pDevice->Activate(IID_IAudioClient, CLSCTX_ALL, NULL, (void**)&pAudioClient);
    EXIT_ON_ERROR(hr)

    hr = pAudioClient->GetDevicePeriod(&hnsDefaultDevicePeriod, NULL);

    hr = pAudioClient->GetMixFormat(&pwfx);
    EXIT_ON_ERROR(hr)

    AdjustFormatTo16Bits(pwfx);

    hTimerWakeUp = CreateWaitableTimer(NULL, FALSE, NULL);

    hr = pAudioClient->Initialize(AUDCLNT_SHAREMODE_SHARED, AUDCLNT_STREAMFLAGS_LOOPBACK, 0, 0, pwfx, NULL);
    EXIT_ON_ERROR(hr)

    // Get the size of the allocated buffer.
    hr = pAudioClient->GetBufferSize(&bufferFrameCount);
    EXIT_ON_ERROR(hr)

    hr = pAudioClient->GetService(IID_IAudioCaptureClient, (void**)&pCaptureClient);
    EXIT_ON_ERROR(hr)

    LARGE_INTEGER liFirstFire;
    liFirstFire.QuadPart = -hnsDefaultDevicePeriod / 2; // negative means relative time
    LONG lTimeBetweenFires = (LONG)hnsDefaultDevicePeriod / 2 / (10 * 1000);

    SetWaitableTimer(hTimerWakeUp, &liFirstFire, lTimeBetweenFires, NULL, NULL, FALSE);

    // Notify the audio sink which format to use.
    hr = pMySink->SetFormat(pwfx);
    EXIT_ON_ERROR(hr)

    // Calculate the actual duration of the allocated buffer.
//    hnsActualDuration = (double)REFTIMES_PER_SEC * bufferFrameCount / pwfx->nSamplesPerSec;

    hr = pAudioClient->Start();  // Start recording.
    EXIT_ON_ERROR(hr)

    HANDLE waitArray[1] = {hTimerWakeUp};

    // Each loop fills about half of the shared buffer.
    while (bDone == FALSE)
    {
        WaitForMultipleObjects(sizeof(waitArray) / sizeof(waitArray[0]), waitArray, FALSE, INFINITE);

        hr = pCaptureClient->GetNextPacketSize(&packetLength);
        EXIT_ON_ERROR(hr)

        while (packetLength != 0)
        {
            // Get the available data in the shared buffer.
            hr = pCaptureClient->GetBuffer(&pData, &numFramesAvailable, &flags, NULL, NULL);
            EXIT_ON_ERROR(hr)

            // Copy the available capture data to the audio sink.
            hr = pMySink->CopyData((char *)pData, numFramesAvailable * pwfx->nBlockAlign, &bDone);
            EXIT_ON_ERROR(hr)

            hr = pCaptureClient->ReleaseBuffer(numFramesAvailable);
            EXIT_ON_ERROR(hr)

            hr = pCaptureClient->GetNextPacketSize(&packetLength);
            EXIT_ON_ERROR(hr)
        }
    }

    hr = pAudioClient->Stop();  // Stop recording.
    EXIT_ON_ERROR(hr)

Exit:
    CoTaskMemFree(pwfx);
    SAFE_RELEASE(pEnumerator)
    SAFE_RELEASE(pDevice)
    SAFE_RELEASE(pAudioClient)
    SAFE_RELEASE(pCaptureClient)

    return hr;
}

int main()
{
    fp = fopen("foobar","wb");
    MyAudioSink test;

    CoInitialize(NULL);
    RecordAudioStream(&test);
    CoUninitialize();

    fclose(fp);
    return 0;
}

播放：

 #include <mmdeviceapi.h>
#include <Audioclient.h>
#include <windows.h>
#include <stdio.h>
#include <string.h>

#define REFTIMES_PER_SEC        10000000
#define REFTIMES_PER_MILLISEC   10000

#define EXIT_ON_ERROR(hres)  \
    if (FAILED(hres)) { goto Exit; }

#define SAFE_RELEASE(punk)  \
    if ((punk) != NULL) { (punk)->Release(); (punk) = NULL; }

const CLSID CLSID_MMDeviceEnumerator    = __uuidof(MMDeviceEnumerator);
const IID IID_IMMDeviceEnumerator       = __uuidof(IMMDeviceEnumerator);
const IID IID_IAudioClient              = __uuidof(IAudioClient);
const IID IID_IAudioRenderClient        = __uuidof(IAudioRenderClient);

FILE *fp = NULL;

class MyAudioSource {
public:
    int SetFormat(WAVEFORMATEX *pwfx);
    int LoadData(UINT32 numFramesAvailable, char *pData, DWORD *pbDone);
};

int MyAudioSource::SetFormat(WAVEFORMATEX *pwfx)
{
    FILE *fp = fopen("render_format.txt", "w");
    char str[128];
    sprintf(str, "wFormatTag \t\tis %x\nnChannels \t\tis %d\nnSamplesPerSec \tis %ld\nnAvgBytesPerSec is %ld\nwBitsPerSample \tis %d",
            pwfx->wFormatTag, pwfx->nChannels, pwfx->nSamplesPerSec, pwfx->nAvgBytesPerSec, pwfx->wBitsPerSample);
    fwrite(str, 1, strlen(str), fp);
    fclose(fp);
    return 0;
}

int MyAudioSource::LoadData(UINT32 numFramesAvailable, char *pData, DWORD *pbDone)
{
    int ret = fread(pData, 1, numFramesAvailable, fp);
    printf("fread returns %d\n", ret);
    if(0 == ret)
        *pbDone = AUDCLNT_BUFFERFLAGS_SILENT;
    return 0;
}

BOOL AdjustFormatTo16Bits(WAVEFORMATEX *pwfx)
{
    BOOL bRet(FALSE);
    if(pwfx->wFormatTag == WAVE_FORMAT_IEEE_FLOAT)
        pwfx->wFormatTag = WAVE_FORMAT_PCM;
    else if(pwfx->wFormatTag == WAVE_FORMAT_EXTENSIBLE)
    {
        PWAVEFORMATEXTENSIBLE pEx = reinterpret_cast<PWAVEFORMATEXTENSIBLE>(pwfx);
        if (IsEqualGUID(KSDATAFORMAT_SUBTYPE_IEEE_FLOAT, pEx->SubFormat))
        {
            pEx->SubFormat = KSDATAFORMAT_SUBTYPE_PCM;
            pEx->Samples.wValidBitsPerSample = 16;
        }
    }
    else
        return bRet;
    pwfx->wBitsPerSample = 16;
    pwfx->nBlockAlign = pwfx->nChannels * pwfx->wBitsPerSample / 8;
    pwfx->nAvgBytesPerSec = pwfx->nBlockAlign * pwfx->nSamplesPerSec;
    bRet = TRUE;
    return bRet;
}

HRESULT PlayAudioStream(MyAudioSource *pMySource)
{
    HRESULT hr;
    REFERENCE_TIME hnsRequestedDuration = REFTIMES_PER_SEC;
    REFERENCE_TIME hnsActualDuration;
    IMMDeviceEnumerator *pEnumerator = NULL;
    IMMDevice *pDevice = NULL;
    IAudioClient *pAudioClient = NULL;
    IAudioRenderClient *pRenderClient = NULL;
    WAVEFORMATEX *pwfx = NULL;
    UINT32 bufferFrameCount;
    UINT32 numFramesAvailable;
    UINT32 numFramesPadding;
    BYTE *pData;
    DWORD flags = 0;

    hr = CoCreateInstance(CLSID_MMDeviceEnumerator, NULL, CLSCTX_ALL, IID_IMMDeviceEnumerator, (void**)&pEnumerator);
    EXIT_ON_ERROR(hr)

    hr = pEnumerator->GetDefaultAudioEndpoint(eRender, eConsole, &pDevice);
    EXIT_ON_ERROR(hr)

    hr = pDevice->Activate(IID_IAudioClient, CLSCTX_ALL, NULL, (void**)&pAudioClient);
    EXIT_ON_ERROR(hr)

    hr = pAudioClient->GetMixFormat(&pwfx);
    EXIT_ON_ERROR(hr)

    AdjustFormatTo16Bits(pwfx);

    hr = pAudioClient->Initialize(AUDCLNT_SHAREMODE_SHARED, 0, hnsRequestedDuration, 0, pwfx, NULL);
    EXIT_ON_ERROR(hr)

    // Tell the audio source which format to use.
    hr = pMySource->SetFormat(pwfx);
    EXIT_ON_ERROR(hr)

    // Get the actual size of the allocated buffer.
    hr = pAudioClient->GetBufferSize(&bufferFrameCount);
    EXIT_ON_ERROR(hr)

    hr = pAudioClient->GetService(IID_IAudioRenderClient, (void**)&pRenderClient);
    EXIT_ON_ERROR(hr)

    // Grab the entire buffer for the initial fill operation.
    hr = pRenderClient->GetBuffer(bufferFrameCount, &pData);
    EXIT_ON_ERROR(hr)

    // Load the initial data into the shared buffer.
    hr = pMySource->LoadData(bufferFrameCount * pwfx->nBlockAlign, (char *)pData, &flags);
    EXIT_ON_ERROR(hr)

    hr = pRenderClient->ReleaseBuffer(bufferFrameCount, flags);
    EXIT_ON_ERROR(hr)

    // Calculate the actual duration of the allocated buffer.
    hnsActualDuration = (double)REFTIMES_PER_SEC * bufferFrameCount / pwfx->nSamplesPerSec;

    hr = pAudioClient->Start();  // Start playing.
    EXIT_ON_ERROR(hr)

    // Each loop fills about half of the shared buffer.
    while (flags != AUDCLNT_BUFFERFLAGS_SILENT)
    {
        // Sleep for half the buffer duration.
        Sleep((DWORD)(hnsActualDuration / REFTIMES_PER_MILLISEC / 2));

        // See how much buffer space is available.
        hr = pAudioClient->GetCurrentPadding(&numFramesPadding);
        EXIT_ON_ERROR(hr)

        numFramesAvailable = bufferFrameCount - numFramesPadding;

        // Grab all the available space in the shared buffer.
        hr = pRenderClient->GetBuffer(numFramesAvailable, &pData);
        EXIT_ON_ERROR(hr)

        // Get next 1/2-second of data from the audio source.
        hr = pMySource->LoadData(numFramesAvailable * pwfx->nBlockAlign, (char *)pData, &flags);
        EXIT_ON_ERROR(hr)

        hr = pRenderClient->ReleaseBuffer(numFramesAvailable, flags);
        EXIT_ON_ERROR(hr)
    }

    // Wait for last data in buffer to play before stopping.
    Sleep((DWORD)(hnsActualDuration / REFTIMES_PER_MILLISEC / 2));

    hr = pAudioClient->Stop();  // Stop playing.
    EXIT_ON_ERROR(hr)

Exit:
    CoTaskMemFree(pwfx);
    SAFE_RELEASE(pEnumerator)
    SAFE_RELEASE(pDevice)
    SAFE_RELEASE(pAudioClient)
    SAFE_RELEASE(pRenderClient)

    return hr;
}

int main()
{
    fp = fopen("foobar","rb");
    MyAudioSource test;

    CoInitialize(NULL);
    PlayAudioStream(&test);
    CoUninitialize();

    fclose(fp);
    return 0;
}

能保存为pcm格式吗