IAMStreamSelect::Info method (strmif.h)
[The feature associated with this page, DirectShow, is a legacy feature. It has been superseded by MediaPlayer, IMFMediaEngine, and Audio/Video Capture in Media Foundation. Those features have been optimized for Windows 10 and Windows 11. Microsoft strongly recommends that new code use MediaPlayer, IMFMediaEngine and Audio/Video Capture in Media Foundation instead of DirectShow, when possible. Microsoft suggests that existing code that uses the legacy APIs be rewritten to use the new APIs if possible.]
The Info method retrieves information about a given stream.
Syntax
HRESULT Info(
[in] long lIndex,
[out] AM_MEDIA_TYPE **ppmt,
[out] DWORD *pdwFlags,
[out] LCID *plcid,
[out] DWORD *pdwGroup,
[out] LPWSTR *ppszName,
[out] IUnknown **ppObject,
[out] IUnknown **ppUnk
);
Parameters
[in] lIndex
Zero-based index of the stream.
[out] ppmt
Address of a variable that receives a pointer to the stream's media type. This parameter is optional and can be NULL. If the value is non-NULL, the method returns a pointer to an AM_MEDIA_TYPE structure. The caller must delete the structure, including the format block. (You can use the DeleteMediaType function from the DirectShow base-class library.)
[out] pdwFlags
Pointer to a variable that receives one of the following values:
| Value | Description |
|---|---|
| Zero | This stream is disabled. |
| AMSTREAMSELECTINFO_ENABLED | The stream is enabled, and others in this group might be enabled too. |
| AMSTREAMSELECTINFO_EXCLUSIVE | This stream is the only enabled stream in the group. |
This parameter is optional and can be NULL.
[out] plcid
Pointer to a variable that receives a locale context (LCID) value. If the stream is associated with a particular locale, the LCID is returned in this variable. Otherwise, the variable receives the value zero. This parameter is optional and can be NULL.
[out] pdwGroup
Pointer to a variable that receives the logical group with which the stream is associated. This parameter is optional and can be NULL.
[out] ppszName
Address of a variable that receives a pointer to the stream name. The caller must free the returned string by calling the CoTaskMemFree function. This parameter is optional and can be NULL.
[out] ppObject
Address of a variable that receives an IUnknown interface pointer. The method might return a pointer to a pin or filter associated with the stream, or it might return the value NULL. If the method returns a non-NULL value, the caller must release the IUnknown pointer.
Calling the IAMStreamSelect::Enable method might invalidate the object returned by this method.
This parameter is optional and can be NULL.
The MPEG-1 Stream Splitter, MPEG-2 Splitter, and SAMI (CC) Parser filters return a pointer to the pin associated with the selected stream.
[out] ppUnk
Address of a variable that receives an IUnknown interface pointer. The method might return a pointer to an interface that is specific to the stream, or it might return the value NULL. If the method returns a non-NULL value, the caller must release the IUnknown pointer. This parameter is optional and can be NULL.
The MPEG-1 Stream Splitter, MPEG-2 Splitter, and SAMI (CC) Parser filters all return the value NULL. Third party filters might return a pointer to a custom filter interface.
Return value
Returns an HRESULT value. Possible values include the following.
| Return code | Description |
|---|---|
|
Failure. |
|
Insufficient memory. |
|
The index is out of range. |
|
Success. |
Requirements
| Requirement | Value |
|---|---|
| Minimum supported client | Windows 2000 Professional [desktop apps only] |
| Minimum supported server | Windows 2000 Server [desktop apps only] |
| Target Platform | Windows |
| Header | strmif.h (include Dshow.h) |
| Library | Strmiids.lib |