IAsyncReader::WaitForNext
A version of this page is also available for
4/8/2010
This method blocks until the next read requested through IAsyncReader::Request completes or the time-out occurs.
Syntax
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 Value
Returns an HRESULT value that depends on the implementation of the interface. Current DirectShow implementation return values include the following.
| 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.
Requirements
| Windows Embedded CE | Windows CE 2.12 and later |
| Windows Mobile | Windows Mobile Version 5.0 and later |
| Note | Microsoft DirectShow applications and DirectShow filters have different include file and Library requirements For more information, see Setting Up the Build Environment, Version 2.12 requires DXPAK 1.0 or later |