ID3D11VideoContext::VideoProcessorSetStreamLumaKey method (d3d11.h)
Sets the luma key for an input stream on the video processor.
void VideoProcessorSetStreamLumaKey( [in] ID3D11VideoProcessor *pVideoProcessor, [in] UINT StreamIndex, [in] BOOL Enable, [in] FLOAT Lower, [in] FLOAT Upper );
The zero-based index of the input stream. To get the maximum number of streams, call ID3D11VideoProcessorEnumerator::GetVideoProcessorCaps and check the MaxStreamStates structure member.
Specifies whether luma keying is enabled.
The lower bound for the luma key. The valid range is [0…1]. If Enable is FALSE, this parameter is ignored.
The upper bound for the luma key. The valid range is [0…1]. If Enable is FALSE, this parameter is ignored.
To use this feature, the driver must support luma keying, indicated by the D3D11_VIDEO_PROCESSOR_FEATURE_CAPS_LUMA_KEY capability flag. To query for this capability, call ID3D11VideoProcessorEnumerator::GetVideoProcessorCaps. In addition, if the input format is RGB, the device must support the D3D11_VIDEO_PROCESSOR_FORMAT_CAPS_RGB_LUMA_KEY capability.
The values of Lower and Upper give the lower and upper bounds of the luma key, using a nominal range of [0...1]. Given a format with n bits per channel, these values are converted to luma values as follows:
val = f * ((1 << n)-1)
Any pixel whose luma value falls within the upper and lower bounds (inclusive) is treated as transparent.
For example, if the pixel format uses 8-bit luma, the upper bound is calculated as follows:
BYTE Y = BYTE(max(min(1.0, Upper), 0.0) * 255.0)
Note that the value is clamped to the range [0...1] before multiplying by 255.
|Minimum supported client||Windows 8 [desktop apps | UWP apps]|
|Minimum supported server||Windows Server 2012 [desktop apps | UWP apps]|