MFCreateSinkWriterFromURL function (mfreadwrite.h)

Creates the sink writer from a URL or byte stream.

Syntax

HRESULT MFCreateSinkWriterFromURL(
  [in]  LPCWSTR       pwszOutputURL,
  [in]  IMFByteStream *pByteStream,
  [in]  IMFAttributes *pAttributes,
  [out] IMFSinkWriter **ppSinkWriter
);

Parameters

[in] pwszOutputURL

A null-terminated string that contains the URL of the output file. This parameter can be NULL.

[in] pByteStream

Pointer to the IMFByteStream interface of a byte stream. This parameter can be NULL.

If this parameter is a valid pointer, the sink writer writes to the provided byte stream. (The byte stream must be writable.) Otherwise, if pByteStream is NULL, the sink writer creates a new file named pwszOutputURL.

[in] pAttributes

Pointer to the IMFAttributes interface. You can use this parameter to configure the sink writer. For more information, see Sink Writer Attributes. This parameter can be NULL.

[out] ppSinkWriter

Receives a pointer to the IMFSinkWriter interface. The caller must release the interface.

Return value

This function can return one of these values.

Remarks

Call CoInitialize(Ex) and MFStartup before calling this function.

The first three parameters to this function can be NULL; however, only certain combinations are valid:

The pAttributes parameter is required in the first case and optional in the others.

• Case 1: Specify a byte stream without a URL. The pAttributes parameter must point to an attribute store that contains the MF_TRANSCODE_CONTAINERTYPE attribute. The sink writer uses the MF_TRANSCODE_CONTAINERTYPE attribute to determine the type of file container to write, such as ASF or MP4.
• Case 2: Specify a URL without a byte stream. The sink writer creates a new file named pwszOutputURL. If pAttributes specifies an attribute store with the MF_TRANSCODE_CONTAINERTYPE attribute, the sink writer uses that attribute to determine the type of file container. Otherwise, if the MF_TRANSCODE_CONTAINERTYPE attribute is absent or pAttributes is NULL, the sink writer uses the file name extension to select the container type; for example, ".asf" for an ASF file.
• Case 3: Specify both a URL and a byte stream. The sink writer writes to the byte stream. The URL provided in pwszOutputURL is informational only; the sink writer does not create a new file. If pAttributes specifies an attribute store with the MF_TRANSCODE_CONTAINERTYPE attribute, the sink writer uses that attribute to determine the type of file container. Otherwise, the sink writer uses the file name extension to select the container type. The MF_TRANSCODE_CONTAINERTYPE attribute overrides the URL file name extension in this case.

Requirements

See also

Media Foundation Functions