MF_MT_ORIGINAL_4CC attribute

Contains the original codec FOURCC for a video stream.

Data type

UINT32

Get/set

To get this attribute, call IMFAttributes::GetUINT32.

To set this attribute, call IMFAttributes::SetUINT32.

Applies to

IMFMediaType

Remarks

Depending on the source file, the AVI media source might set this attribute on the media types that it offers.

An AVI file contains a stream header for each stream in the file. The AVI media source translates the stream header into a media type. For compressed video streams, the stream header contains a FOURCC that identifies the video codec. In most cases, the AVI media source converts this FOURCC directly to a subtype GUID, as described in the topic Video Subtype GUIDs. In some cases, however, it maps the original FOURCC to another FOURCC that is equivalent. If so, the media source stores the original FOURCC in the media type, using the MF_MT_ORIGINAL_4CC attribute.

The FOURCC mappings are stored in the Registry under the following key:

HKEY_CLASSES_ROOT\MediaFoundation\MapVideo4cc

Each entry is a DWORD value. The name of the entry is the hexadecimal representation of the FOURCC, without an "0x" prefix, and with the first character appearing first in the string. For example, the FOURCC code 'abcd' would appear as "61626364". The value of the entry is the equivalent FOURCC code.

The GUID constant for this attribute is exported from mfuuid.lib.

Requirements

See also

Alphabetical List of Media Foundation Attributes

Media Type Attributes