A number of new pix_fmts* have been added to AviSynth+:
16-bit packed RGB and RGBA
10-, 12-, 14, and 16-bit YUV 4:2:0, 4:2:2, and 4:4:4
8-, 10-, 12-, 14-, and 16-bit Planar RGB
8-, 10-, 12-, 14-, and 16-bit Planar YUVA and Planar RGBA
10-, 12-, 14-, and 16-bit GRAY variants
32-bit floating point Planar YUV(A), Planar RGB(A), and GRAY

*some of which are not currently available pix_fmts here and were
 not added to the demuxer due to this
Signed-off-by: Diego Biurrun <diego@biurrun.de>