IAMWstDecoder interface

The IAMWstDecoder interface sets and retrieves information about World Standard Teletext (WST). The WST Decoder filter implements this interface.

Methods

The IAMWstDecoder interface has these methods.

Method	Description
IAMWstDecoder::GetAnswerMode	Downstream filters use the GetAnswerMode method to retrieve the current answer mode.
IAMWstDecoder::GetBackgroundColor	Downstream filters use the GetBackgroundColor method to retrieve the current physical color used in color keying the background for overlay mixing.
IAMWstDecoder::GetCurrentPage	Downstream filters use the GetCurrentPage method to retrieve the current WST page.
IAMWstDecoder::GetCurrentService	Applications use the GetCurrentService method to retrieve the current WST service.
IAMWstDecoder::GetDecoderLevel	Applications use the GetDecoderLevel method to retrieve the WST decoder level. This method is not implemented and always returns AM_WST_LEVEL_1_5.
IAMWstDecoder::GetDrawBackgroundMode	Downstream filters use the GetDrawBackgroundMode method to determine whether the caption text background is opaque or transparent.
IAMWstDecoder::GetHoldPage	Downstream filters use the GetHoldPage method to determine whether the current WST page is held. When the WST decoder holds a page, any updates from the TV stream are turned off. It is though the page was paused in real time.
IAMWstDecoder::GetOutputFormat	Downstream filters use the GetOutputFormat method to retrieve the size, bit depth, and other parameters of the output video.
IAMWstDecoder::GetRedrawAlways	Downstream filters use the GetRedrawAlways method to retrieve a value that indicates whether the whole output bitmap is redrawn for each sample.
IAMWstDecoder::GetServiceState	Applications use the GetServiceState method to retrieve the current service state.
IAMWstDecoder::SetAnswerMode	Downstream filters use the SetAnswerMode method to assign the current answer mode.
IAMWstDecoder::SetBackgroundColor	Downstream filters use the SetBackgroundColor method to assign the physical color to be used in color keying the background for overlay mixing.
IAMWstDecoder::SetCurrentPage	Downstream filters use the SetCurrentPage method to assign the current page.
IAMWstDecoder::SetDrawBackgroundMode	Downstream filters use the SetDrawBackgroundMode method to assign whether the caption text background is to be opaque or transparent.
IAMWstDecoder::SetHoldPage	Downstream filters use the SetHoldPage method to tell the WST decoder to hold the current WST page. When the WST decoder holds a page, any updates from the TV stream are turned off. It is as though the page was paused in real time.
IAMWstDecoder::SetOutputFormat	Downstream filters use the SetOutputFormat method to define an output video format.
IAMWstDecoder::SetRedrawAlways	Downstream filters use the SetRedrawAlways method to determine whether the whole output bitmap should be redrawn for each sample.
IAMWstDecoder::SetServiceState	Applications use the SetServiceState method to assign the service state.

Requirements

Minimum supported client	Windows XP [desktop apps only]
Minimum supported server	Windows Server 2003 [desktop apps only]
Target Platform	Windows
Header	iwstdec.h