IAsyncReader::WaitForNext
Blocks until the next read requested through IAsyncReader::Request completes or the time-out occurs.
HRESULT WaitForNext(
DWORD dwTimeout,
IMediaSample **ppSample,
DWORD *pdwUser );
Parameters
- dwTimeout
[in] Time-out in milliseconds; can be zero or INFINITE. - ppSample
[out] Completed sample. - pdwUser
User context.
Return Values
Returns an HRESULT value that depends on the implementation of the interface. Current DirectShow implementation return values include:
| Value | Description |
|---|---|
| VFW_E_TIMEOUT | A time-out has expired. |
| VFW_E_WRONG_STATE | The operation could not be performed because the filter is in the wrong state. |
| E_FAIL | Failure. |
| S_OK | Success. |
Remarks
Samples may not be returned in order. If there is a read error of any sort, a notification will already have been sent by the source filter, and HRESULT will be an error. If ppSample is not null, a request has been completed with the result code returned.
The pdwUser parameter returns the caller's context DWORD corresponding to the sample returned.
Last updated on Tuesday, July 13, 2004
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