KSPROPERTY_VIDEOCOMPRESSION_WINDOWSIZE
The KSPROPERTY_VIDEOCOMPRESSION_WINDOWSIZE property controls the data rate that describes the average frame size. This property must be implemented.
Usage Summary Table
| Get | Set | Target | Property descriptor type | Property value type |
|---|---|---|---|---|
Yes |
Yes |
Filter |
LONG |
The property value (operation data) is a LONG that specifies a data rate that represents the average frame size.
Remarks
The Value member of the KSPROPERTY_VIDEOCOMPRESSION_S structure specifies the window size.
Minidrivers that support this property should set the KS_CompressionCaps_CanWindow flag in the Capabilities member of the KSPROPERTY_VIDEOCOMPRESSION_GETINFO_S structure that retrieves the minidriver's video compression capabilities. If a minidriver sets the KS_CompressionCaps_CanWindow flag, it should provide both get and set support for the property.
For a window of size n, the average frame size of any consecutive n frames must not exceed the stream's specified data rate, although individual frames may be larger or smaller. For example, if the data rate has been set to 150 kilobytes per second (KBps) on a 15 frame per second (fps) movie, the average size of each frame must therefore be less than or equal to 10 kilobytes. Individual frames may be larger or smaller just so long as the average size (calculated across 15 frames per second of movie) is less than or equal to 10 kilobytes.
Requirements
Header |
Ksmedia.h (include Ksmedia.h) |