关于directshow 麦克风音频采集问题

[howehowe]

我根据directshow sample的创建了一个capture 出来采集麦克风的输入，直接连上renderer实时播放，但总是有1s延时，我的设置是这样的。


// Find number of bytes in one second
long lBytesPerSecond = (long) (nBytesPerSample * nFrequency * nChannels);

// Set to 50ms worth of data ， DEFAULT_BUFFER_TIME = 0.05
long lBufferSize = (long) ((float) lBytesPerSecond * DEFAULT_BUFFER_TIME);

ALLOCATOR_PROPERTIES prop={0};
prop.cbBuffer = lBufferSize;
prop.cBuffers = 6;
prop.cbAlign = nBytesPerSample * nChannels;
hr = pNeg->SuggestAllocatorProperties(&prop);

[howehowe]

但在winxp 将麦克风输出的音量取消静音的话或者在win7侦听麦克风，麦克风输出的声音延时是很少的，几乎没有~~用directshow怎样才可以做到这样·？？或者有什么方法可以做到~？

[howehowe]

自己顶

[伪装者1982]

调用声卡采集端的pin上的IID_IAMBufferNegotiation接口设置,下面设置是50ms延时

nFrequency = USE_SAMPLE_RATE;//48000;

// Find number of bytes in one second
long lBytesPerSecond = (long) (nBytesPerSample * nFrequency * nChannels);

// Set to 50ms worth of data
long lBufferSize = (long) ((float) lBytesPerSecond * 0.05);

// Get the buffer negotiation interface for each pin,
// since there could be both a Capture and a Preview pin.

// Get buffer negotiation interface
hr = pPin->QueryInterface(IID_IAMBufferNegotiation, (void **)&pNeg);
if (FAILED(hr))
{
return hr;
}
ALLOCATOR_PROPERTIES prop={0};
//hr = pNeg->GetAllocatorProperties(&prop);
// Set the buffer size based on selected settings
prop.cbBuffer = lBufferSize;
prop.cBuffers = 6;
prop.cbAlign = nBytesPerSample * nChannels;
hr = pNeg->SuggestAllocatorProperties(&prop);
SAFE_RELEASE(pNeg);