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Capture a Type-1 DV File

  • Artigo
 
Microsoft DirectShow 9.0

Capture a Type-1 DV File

A type-1 DV AVI file contains a single interleaved stream. To capture a type-1 file while previewing, use the filter graph shown in the following diagram.

Type-1 Capture with Preview

Filters in this graph include:

  • The Smart Tee filter splits the interleaved DV into a capture stream and a preview stream. Both streams contain the same interleaved data.
  • The AVI Mux and File Writer write the interleaved stream to disk.
  • The DV Splitter splits the interleaved stream into a DV video stream and an audio stream. Both streams are rendererd for preview.
  • The DV Video Decoder decodes the DV video stream for previewing.

Build this graph as follows:

ICaptureGraphBuilder2 *pBuilder;  // Capture graph builder.
IBaseFilter           *pDV;       // DV capture filter (MSDV)
IBaseFilter           *pAviMux    // Avi Mux filter.

// Initialize pDV (not shown). 
// Create and initialize the Capture Graph Builder (not shown).

// Create the file-writing section of the graph.
hr = pBuilder->SetOutputFileName(&MEDIASUBTYPE_Avi, 
    OLESTR("C:\\Example1.avi"), &pAviMux, 0);

// Render the capture stream.
hr = pBuilder->RenderStream(&PIN_CATEGORY_CAPTURE, &MEDIATYPE_Interleaved, 
    pDV, 0, pAviMux);

// Render the preview stream.
hr = pBuilder->RenderStream(&PIN_CATEGORY_PREVIEW, &MEDIATYPE_Interleaved,
    pDV, 0, 0);

// Remember to release all interfaces.
  1. Call ICaptureGraphBuilder2::SetOutputFileName to connect the AVI Mux filter to the File Writer filter.
  2. Call ICaptureGraphBuilder2::RenderStream with the pin category PIN_CATEGORY_CAPTURE to render the capture stream. The Capture Graph Builder automatically inserts the Smart Tee filter.
  3. Call RenderStream again, but with the pin category PIN_CATEGORY_PREVIEW, to render the preview stream. Skip this call if you do not want to preview the video.

For both calls to RenderStream, the media type is MEDIATYPE_Interleaved, meaning interleaved DV video. In this code, the Capture Graph Builder automatically adds every filter that is needed, except for the MSDV capture filter.

See Also