Fill the r, g, b values used for computing the c->pal_yuv table in the

case where the source format is PIX_FMT_GRAY8.

This is required as PIX_FMT_GRAY8 has been declared as a paletted
format in FFmpeg r22191, fix GRAY8 -> RGB conversion.

Originally committed as revision 30826 to svn://svn.mplayerhq.hu/mplayer/trunk/libswscale

libswscale/swscale.c

@@ -1849,6 +1849,8 @@ int sws_scale(SwsContext *c, const uint8_t* const src[], const int srcStride[],
                 r= (i>>3    )*255;
                 g= ((i>>1)&3)*85;
                 b= (i&1     )*255;
+            } else if(c->srcFormat == PIX_FMT_GRAY8) {
+                r = g = b = i;
             } else {
                 assert(c->srcFormat == PIX_FMT_BGR4_BYTE);
                 b= (i>>3    )*255;