fix YUV tables

git-svn-id: svn://svn.icculus.org/twilight/trunk/darkplaces@8867 d7cf8633-e32d-0410-b094-e92efae38249

diff --git a/cl_screen.c b/cl_screen.c
index ed6f31dcf3ff92e122e322ffd4d7586423dc9a97..66c2667e34f0a58c154b5424485073b9e7f7e23b 100644 (file)
--- a/cl_screen.c
+++ b/cl_screen.c
@@ -1029,22 +1029,23 @@ Cr = R *  .500 + G * -.419 + B * -.0813 + 128.;
                r = 255*cls.capturevideo.vidramp[i]/65535.0;
                g = 255*cls.capturevideo.vidramp[i+256]/65535.0;
                b = 255*cls.capturevideo.vidramp[i+512]/65535.0;
+               // NOTE: we have to round DOWN here, or integer overflows happen. Sorry for slightly wrong looking colors sometimes...
                // Y weights from RGB
-               cls.capturevideo.rgbtoyuvscaletable[0][0][i] = (short)(r *  0.299 + 0.5);
-               cls.capturevideo.rgbtoyuvscaletable[0][1][i] = (short)(g *  0.587 + 0.5);
-               cls.capturevideo.rgbtoyuvscaletable[0][2][i] = (short)(b *  0.114 + 0.5);
+               cls.capturevideo.rgbtoyuvscaletable[0][0][i] = (short)(r *  0.299);
+               cls.capturevideo.rgbtoyuvscaletable[0][1][i] = (short)(g *  0.587);
+               cls.capturevideo.rgbtoyuvscaletable[0][2][i] = (short)(b *  0.114);
                // Cb weights from RGB
-               cls.capturevideo.rgbtoyuvscaletable[1][0][i] = (short)(r * -0.169 + 0.5);
-               cls.capturevideo.rgbtoyuvscaletable[1][1][i] = (short)(g * -0.332 + 0.5);
-               cls.capturevideo.rgbtoyuvscaletable[1][2][i] = (short)(b *  0.500 + 0.5);
+               cls.capturevideo.rgbtoyuvscaletable[1][0][i] = (short)(r * -0.169);
+               cls.capturevideo.rgbtoyuvscaletable[1][1][i] = (short)(g * -0.332);
+               cls.capturevideo.rgbtoyuvscaletable[1][2][i] = (short)(b *  0.500);
                // Cr weights from RGB
-               cls.capturevideo.rgbtoyuvscaletable[2][0][i] = (short)(r *  0.500 + 0.5);
-               cls.capturevideo.rgbtoyuvscaletable[2][1][i] = (short)(g * -0.419 + 0.5);
-               cls.capturevideo.rgbtoyuvscaletable[2][2][i] = (short)(b * -0.0813 + 0.5);
+               cls.capturevideo.rgbtoyuvscaletable[2][0][i] = (short)(r *  0.500);
+               cls.capturevideo.rgbtoyuvscaletable[2][1][i] = (short)(g * -0.419);
+               cls.capturevideo.rgbtoyuvscaletable[2][2][i] = (short)(b * -0.0813);
                // range reduction of YCbCr to valid signal range
-               cls.capturevideo.yuvnormalizetable[0][i] = 16 + i * (236-16) / 256 + 0.5;
-               cls.capturevideo.yuvnormalizetable[1][i] = 16 + i * (240-16) / 256 + 0.5;
-               cls.capturevideo.yuvnormalizetable[2][i] = 16 + i * (240-16) / 256 + 0.5;
+               cls.capturevideo.yuvnormalizetable[0][i] = 16 + i * (236-16) / 256;
+               cls.capturevideo.yuvnormalizetable[1][i] = 16 + i * (240-16) / 256;
+               cls.capturevideo.yuvnormalizetable[2][i] = 16 + i * (240-16) / 256;
        }
 
        if (cl_capturevideo_ogg.integer)