Export (0) Print
Expand All

Video/Image Compression Manager (Compact 2013)

3/26/2014

The AVI decompressor is a wrapper filter for installable decompressors that support the Video Compression Manager (VCM) interface. The VCM interface is not a part of the DirectShow architecture, so a wrapper filter is required to enable these compressors to function in the context of a filter graph.

When the Filter Graph Manager is building a graph to render an AVI file, it checks the Four-Character Codes (FOURCC) in the file's AVI header to determine whether the video stream is compressed.

If it is, the Filter Graph Manager adds the AVI decompressor, which then searches the registry for an installed decompressor that can handle the file. All this happens automatically; your application is not responsible for these details.

On its upstream pin, the AVI decompressor typically connects to the AVI splitter filter. On its output pin, it typically connects to the video renderer filter.

The following table shows the filter properties.

Filter property

Description

Filter Interfaces

IBaseFilter

Input Pin Media Types

MEDIATYPE_Video, MEDIASUBTYPE_NULL, FORMAT_VideoInfo. The subtype must correspond to an old-style FOURCC. For more information, see FOURCCMap Class.

Input Pin Interfaces

IMemInputPin, IPin, IQualityControl

Output Pin Media Types

MEDIATYPE_Video, MEDIASUBTYPE_NULL, FORMAT_VideoInfo

Output Pin Interfaces

IMediaPosition, IMediaSeeking, IPin, IQualityControl

Filter CLSID

CLSID_AVIDec

Property Page CLSID

No property page.

Executable

Quartz.dll

Merit

MERIT_NORMAL

Filter Category

CLSID_LegacyAmFilterCategory

The media subtype on the pins is built from the Four-Character Codes (FOURCC) in the AVI file.

Show:
© 2014 Microsoft