BufferCB未被SampleGrabber調用

我正在使用SampleGrabber獲取音頻數據，但是我的BufferCB方法未被執行。我究竟做錯了什麼？BufferCB未被SampleGrabber調用

//add Sample Grabber 
      IBaseFilter pSampleGrabber = (IBaseFilter)Activator.CreateInstance(Type.GetTypeFromCLSID(CLSID_SampleGrabber)); 
      hr = pGraph.AddFilter(pSampleGrabber, "SampleGrabber"); 
      checkHR(hr, "Can't add Sample Grabber"); 

     AMMediaType pSampleGrabber_pmt = new AMMediaType(); 
     //pSampleGrabber_pmt.majorType = MediaType.Audio; 
     pSampleGrabber_pmt.subType = MediaSubType.PCM; 
     pSampleGrabber_pmt.formatType = FormatType.WaveEx; 
     pSampleGrabber_pmt.fixedSizeSamples = true; 
     pSampleGrabber_pmt.formatSize = 18; 
     pSampleGrabber_pmt.sampleSize = 2; 

     WaveFormatEx pSampleGrabber_Format = new WaveFormatEx(); 
     pSampleGrabber_Format.wFormatTag = 1; 
     pSampleGrabber_Format.nChannels = 1; 
     pSampleGrabber_Format.nSamplesPerSec = 48000; 
     pSampleGrabber_Format.nAvgBytesPerSec = 96000; 
     pSampleGrabber_Format.nBlockAlign = 2; 
     pSampleGrabber_Format.wBitsPerSample = 16; 
     pSampleGrabber_pmt.formatPtr = Marshal.AllocCoTaskMem(Marshal.SizeOf(pSampleGrabber_Format)); 
     Marshal.StructureToPtr(pSampleGrabber_Format, pSampleGrabber_pmt.formatPtr, false); 
     hr = ((ISampleGrabber)pSampleGrabber).SetMediaType(pSampleGrabber_pmt); 
     DsUtils.FreeAMMediaType(pSampleGrabber_pmt); 
     checkHR(hr, "Can't set media type to sample grabber"); 

     ISampleGrabber pGrabber = new SampleGrabber() as ISampleGrabber; 
     pGrabber = (ISampleGrabber)pSampleGrabber; 
     pGrabber.SetCallback(null, 1);

我BufferCB方法類似於

public int BufferCB(double SampleTime, IntPtr pBuffer, int BufferLen) 
     { 

      return 0; 
     }

來源

2012-05-31 CharlesBryan

您創建和配置一個實例pSampleGrabber，然後你是你的回調連接到另一個未使用的閒置情況pGrabber。

你需要

pSampleGrabber as ISampleGrabber

，而不是

new SampleGrabber() as ISampleGrabber

來源

2012-05-31 08:22:24

我得到「的對象引用需要非靜態字段，方法或屬性」 – CharlesBryan

哦，等一下錯誤，你正在做的更奇怪的事情。 'pGrabber = new ...'完全沒用，因爲你正在立即發佈這個實例。 'SetCallback（null'） - 你期望在這裏做什麼？你正在傳遞'null'，你的回調是預期的... –

哦，我明白了..所以我需要實現ISampleGrabberCB，然後把我的BufferCB實現在那裏？ – CharlesBryan

BufferCB未被SampleGrabber調用

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