alpha clip _Range?

[AkarinVS]

should alpha clip defaults to full range?

currently lsmas uses the main clip's range to set the alpha clip's range, primaries, transfer, and matrix.

L-SMASH-Works/VapourSynth/video_output.c

Lines 1066 to 1075 in 8ba7892

	if( vs_format->colorFamily != cmRGB )
	{
	if( av_frame->color_range != AVCOL_RANGE_UNSPECIFIED )
	vsapi->propSetInt( props, "_ColorRange", av_frame->color_range == AVCOL_RANGE_MPEG, paReplace );
	vsapi->propSetInt( props, "_Primaries", av_frame->color_primaries, paReplace );
	vsapi->propSetInt( props, "_Transfer", av_frame->color_trc, paReplace );
	vsapi->propSetInt( props, "_Matrix", av_frame->colorspace, paReplace );
	if( av_frame->chroma_location > 0 )
	vsapi->propSetInt( props, "_ChromaLocation", av_frame->chroma_location - 1, paReplace );
	}

For alpha clip, primaries and matrix are irrelevant, but I'm not sure about range and transfer.

I'd guess all alpha should be full range, but is this true?
What about transfer?

Also, is there a YUV image/video format that also includes alpha channel?

[YomikoR]

They are just masks, and _Range is the only required property.