[gst-devel] [ffmpegcolorspace] rgb 2 yuv

[Julien Isorce]

Hi,

When I convert a pure black image to yuv using ffmpegcolorspace, then y is
equal to 16, u and v are equal to 0.
 If the input is pure white then y is equal to 251.

proof:
gst-launch-0.10 videotestsrc num_buffers=1 pattern=2 ! "video/x-raw-rgb,
bpp=24, depth=24, width=4, height=4" ! ffmpegcolorspace ! "video/x-raw-yuv,
format=(fourcc)YUY2" ! filesink location=black.yuv

then hexedit black.yuv ->
(y1 u y2 v)
10 80 10 80 ->  16 128 16 128
10 80 10 80
10 80 10 80
10 80 10 80

The 128 is ok but I do not understand why y is equal to 16. Why not 0 ?

Sincerely

Julien
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