Question

我有直接显示过滤器，它接受输入并处理它并将结果提供给outputpin。

我想将这个过滤器输出数据写入文件......我想在其过滤器类中进行操作。所以我想得到输出引脚缓冲区数据。

如何在其过滤器中获取outputpin的最终数据？我该怎么做？

不是：输出引脚来自CBaseOutputPin。这是一个开源过滤器，它“神奇地”:-)把wright数据放到它的输出引脚，我无法弄清楚怎么样..

更新

这是一个简单的说明：

Media Source ---->  GFilter ----> FileWriter

我有GFilter的源代码......我没有FileWriter的源代码......我想做的是让GFilter编写自己的数据......我调试GFilter了解它的转换数据但是我的尝试用错误的数据写这个数据结果......所以我现在就如何简单地在其输出引脚上获取数据......

更新[2]

在Filter outputpin中，过滤器编写器将文件编写器引脚传递给IStreamPtr变量...... Everthing似乎写入变量m_pIStream，类型为[IStreamPtr]

GFilterOutput::CompleteConnect(IPin *pReceivePin)
{


    // make sure that this is the file writer, supporting
    // IStream, or we will not be able to write out the metadata
    // at stop time
    // m_pIStream  is IStreamPtr type
    m_pIStream = pReceivePin;
    if (m_pIStream == NULL)
    {
        return E_NOINTERFACE;
    }
    return CBaseOutputPin::CompleteConnect(pReceivePin);
}

...

GFilterOutput::Replace(LONGLONG pos, const BYTE* pBuffer, long cBytes)
{
     //OutputDebugStringA("DEBUG: Now at MuxOutput Replace");

    // all media content is written when the graph is running,
    // using IMemInputPin. On stop (during our stop, but after the
    // file writer has stopped), we switch to IStream for the metadata.
    // The in-memory index is updated after a successful call to this function, so
    // any data not written on completion of Stop will not be in the index.
    CAutoLock lock(&m_csWrite);

    HRESULT hr = S_OK;
    if (m_bUseIStream)
    {


        IStreamPtr pStream = GetConnected();
        if (m_pIStream == NULL)
        {
            hr = E_NOINTERFACE;
        } else {
            LARGE_INTEGER liTo;
            liTo.QuadPart = pos;
            ULARGE_INTEGER uliUnused;
            hr = m_pIStream->Seek(liTo, STREAM_SEEK_SET, &uliUnused);
            if (SUCCEEDED(hr))
            {
                ULONG cActual;
                hr = m_pIStream->Write(pBuffer, cBytes, &cActual);
                if (SUCCEEDED(hr) && ((long)cActual != cBytes))
                {
                    hr = E_FAIL;
                }
            }
        }
    } else {
        // where the buffer boundaries lie is not important in this 
        // case, so break writes up into the buffers.
        while (cBytes && (hr == S_OK))
        {
            IMediaSamplePtr pSample;
            hr = GetDeliveryBuffer(&pSample, NULL, NULL, 0);
            if (SUCCEEDED(hr))
            {
                long cThis = min(pSample->GetSize(), cBytes);
                BYTE* pDest;
                pSample->GetPointer(&pDest);
                CopyMemory(pDest, pBuffer,  cThis);
                pSample->SetActualDataLength(cThis);

                // time stamps indicate file position in bytes
                LONGLONG tStart = pos;
                LONGLONG tEnd = pos + cThis;
                pSample->SetTime(&tStart, &tEnd);
                hr = Deliver(pSample);
                if (SUCCEEDED(hr))
                {
                    pBuffer += cThis;
                    cBytes -= cThis;
                    pos += cThis;
                }
            }
        }
    }
    return hr;
}

Answer 1

您有完整的源代码，使用调试器逐步完成，直到您的过滤器调用对等下游过滤器的IPin::Receive，更新/覆盖代码，并且您可以完全控制将数据写入文件等

如何从directshow过滤器输出引脚获取数据？

1 个答案: