ShowAlpha

Revision as of 15:45, 8 November 2015

ShowAlpha(clip clip, string pixel_type)
ShowBlue(clip clip, string pixel_type)
ShowGreen(clip clip, string pixel_type)
ShowRed(clip clip, string pixel_type)

ShowAlpha shows the alpha channel of a RGB32 clip, available in v2.53. ShowBlue/ShowGreen/ShowRed shows the selected channel of a RGB clip, available in v2.56.

In v2.54 ShowAlpha now returns RGB, YUY2, or YV12 via the pixel_type argument. The latter two can be used to layer an RGB clip with alpha transparency data onto a YUV clip using the 3-argument form of Overlay, because when setting pixel_type to YUY2 or YV12 the luma range is [0,255].

In v2.56 ShowAlpha/Red/Green/Blue now returns RGB24, RGB32, YUY2, or YV12 (and in v2.60 also Y8) via the pixel_type argument. For RGB32 output the selected channel is copied to all R, G and B channels, but not the Alpha channel which is left untouched. For YUV output the selected channel is copied to the Luma channel, the chroma channels are set to grey (0x80).

Examples:

# shows alpha channel of clip
AviSource("clip.avi")
ShowAlpha()

# swaps red and blue channels:
AviSource("clip.avi")
MergeRGB(ShowBlue("YV12"), Last, ShowRed("YV12"))

Changelog: