IAMVideoCompression Interface
This interface sets and retrieves video compression properties. It is supported by some video compression filters, and also by some video capture filters that output compressed video. Filters that support this interface expose it through their output pins.
An application can use this interface to control how video is compressed, including characteristics such as the key-frame rate or the compression quality.
A filter that supports this interface might not support every method. Use the IAMVideoCompression::GetInfo method to determine which methods the filter supports.
Note To use this interface on a capture filter, you might need to connect the filter to another filter in the graph.
In addition to the methods inherited from IUnknown, thisinterface exposes the following methods.
| Method | Description |
|---|---|
| get_KeyFrameRate | Retrieves the key-frame rate. |
| get_PFramesPerKeyFrame | Retrieves the P frame frequency. |
| get_Quality | Retrieves the compression quality. |
| get_WindowSize | Retrieves the number of frames over which the compressor must maintain an average data rate. |
| GetInfo | Retrieves information about the filter's compression properties, including capabilities and default values. |
| OverrideFrameSize | Overrides a particular frame's data rate. |
| OverrideKeyFrame | Forces a particular frame to be a key frame. |
| put_KeyFrameRate | Sets the key-frame rate. |
| put_PFramesPerKeyFrame | Sets the predicted (P) frame frequency. |
| put_Quality | Sets the compression quality. |
| put_WindowSize | Sets the number of frames over which the compressor must maintain an average data rate. |
Remarks
Video capture filters automatically exposes this interface if the driver supports the PROPSETID_VIDCAP_VIDEOCOMPRESSION property set.
See Also
DirectShow Interfaces | IAMVideoCompression::GetInfo
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