VP8RGBToY         465 3rdparty/libwebp/dec/vp8l.c       y[i] = VP8RGBToY((p >> 16) & 0xff, (p >> 8) & 0xff, (p >> 0) & 0xff);
VP8RGBToY         616 3rdparty/libwebp/enc/picture.c           VP8RGBToY(r_ptr[offset], g_ptr[offset], b_ptr[offset]);