Edit

Share via

To Configure the Indexer

  • Article

[The feature associated with this page, Windows Media Format 11 SDK, is a legacy feature. It has been superseded by Source Reader and Sink Writer. Source Reader and Sink Writer have been optimized for Windows 10 and Windows 11. Microsoft strongly recommends that new code use Source Reader and Sink Writer instead of Windows Media Format 11 SDK, when possible. Microsoft suggests that existing code that uses the legacy APIs be rewritten to use the new APIs if possible.]

You can configure the indexer before using it to index an ASF file. Each stream in the file can be configured separately, or you can set the same configuration for all streams.

If you are configuring multiple steams for indexing in a file, you must configure them all and then begin indexing. If you configure and index a stream and then configure another stream in the same file, starting the indexer again will delete the first index. This is to comply with the ASF file format.

The following code shows how to configure the indexer. The code assumes that the file to be indexed has two streams: the first is an audio stream which does not need to be indexed, and the second is a video stream. This code shows only how to configure the indexer. To index a file, you must follow the steps presented in To Index an ASF File.

IWMIndexer*  pBaseIndexer = NULL;
IWMIndexer2* pMyIndexer   = NULL;

DWORD          dwInterval;
HRESULT hr = S_OK;

// Initialize COM.
hr = CoInitialize(NULL);

// Create an indexer.
hr = WMCreateIndexer(&pBaseIndexer);

// Retrieve an IWMIndexer2 interface pointer for the indexer just created.
hr = pBaseIndexer->QueryInterface(IID_IWMIndexer2, (void**)&pMyIndexer);

// Release the base indexer.
pBaseIndexer->Release();
pBaseIndexer = NULL;

// Set the index interval to 5 frames.
dwInterval = 5;

// Configure the indexer to create a frame-based index.
hr = pMyIndexer->Configure(2,                    // Stream Number.
                           WMT_IT_FRAME_NUMBERS, // Indexer type.
                           (void *)&dwInterval,  // Index interval.
                           NULL;        // Index type, use default.

// TODO: Index the file. See To Index an ASF File.

// Release the remaining interface.
pMyIndexer->Release();
pMyIndexer = NULL;

Note

The default index type is WMT_IT_NEAREST_CLEAN_POINT. Although you can set the index type to other values, doing so will degrade seeking performance.

 

IWMIndexer2::Configure

To Index an ASF File

WMCreateIndexer

Working with Indexes