IMFSourceResolver::BeginCreateObjectFromURL method (mfidl.h)

Begins an asynchronous request to create a media source or a byte stream from a URL.

Syntax

HRESULT BeginCreateObjectFromURL(
  [in]  LPCWSTR          pwszURL,
  [in]  DWORD            dwFlags,
  [in]  IPropertyStore   *pProps,
  [out] IUnknown         **ppIUnknownCancelCookie,
  [in]  IMFAsyncCallback *pCallback,
  [in]  IUnknown         *punkState
);

Parameters

[in] pwszURL

Null-terminated string that contains the URL to resolve.

[in] dwFlags

Bitwise OR of flags. See Source Resolver Flags.

[in] pProps

Pointer to the IPropertyStore interface of a property store. The method passes the property store to the scheme handler or byte-stream handler that creates the object. The handler can use the property store to configure the object. This parameter can be NULL. For more information, see Configuring a Media Source.

[out] ppIUnknownCancelCookie

Receives an IUnknown pointer or the value NULL. If the value is not NULL, you can cancel the asynchronous operation by passing this pointer to the IMFSourceResolver::CancelObjectCreation method. The caller must release the interface. This parameter can be NULL.

[in] pCallback

Pointer to the IMFAsyncCallback interface of a callback object. The caller must implement this interface.

[in] punkState

Pointer to the IUnknown interface of a state object, defined by the caller. This parameter can be NULL. You can use this object to hold state information. The object is returned to the caller when the callback is invoked.

Return value

The method returns an HRESULT. Possible values include, but are not limited to, those in the following table.

Remarks

The dwFlags parameter must contain either the MF_RESOLUTION_MEDIASOURCE flag or the MF_RESOLUTION_BYTESTREAM flag, but should not contain both.

For local files, you can pass the file name in the pwszURL parameter; the file: scheme is not required.

When the operation completes, the source resolver calls the IMFAsyncCallback::Invoke method. The Invoke method should call IMFSourceResolver::EndCreateObjectFromURL to get a pointer to the object that was created.

The usage of the pProps parameter depends on the implementation of the media source.

Requirements

See also

IMFSourceResolver

Source Resolver