contrast 0 should lead to a grey, not a black image

git-svn-id: svn://svn.mplayerhq.hu/mplayer/trunk@16590 b3059339-0415-0410-9bf9-f77b7e298cf2
This commit is contained in:
reimar 2005-09-25 16:17:03 +00:00
parent d06ea270be
commit f384349dfb
1 changed files with 5 additions and 0 deletions

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@ -563,6 +563,11 @@ static void glSetupYUVFragprog(float brightness, float contrast,
rc = (-16 * ry + (-128) * ru + (-128) * rv) / 255.0 + brightness;
gc = (-16 * gy + (-128) * gu + (-128) * gv) / 255.0 + brightness;
bc = (-16 * by + (-128) * bu + (-128) * bv) / 255.0 + brightness;
// these "center" contrast control so that e.g. a contrast of 0
// leads to a grey image, not a black one
rc += 0.5 - contrast / 2.0;
gc += 0.5 - contrast / 2.0;
bc += 0.5 - contrast / 2.0;
rgamma = 1.0 / rgamma;
ggamma = 1.0 / ggamma;
bgamma = 1.0 / bgamma;