diff options
Diffstat (limited to 'drivers/gpu/drm/sun4i/sun4i_backend.c')
| -rw-r--r-- | drivers/gpu/drm/sun4i/sun4i_backend.c | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/drivers/gpu/drm/sun4i/sun4i_backend.c b/drivers/gpu/drm/sun4i/sun4i_backend.c index 2a9569f16c81..f43c4b0f1e5d 100644 --- a/drivers/gpu/drm/sun4i/sun4i_backend.c +++ b/drivers/gpu/drm/sun4i/sun4i_backend.c @@ -48,8 +48,12 @@ static const u32 sunxi_rgb2yuv_coef[12] = { /* * These coefficients are taken from the A33 BSP from Allwinner. * - * The formula is for each component, each coefficient being multiplied by - * 1024 and each constant being multiplied by 16: + * The first three values of each row are coded as 13-bit signed fixed-point + * numbers, with 10 bits for the fractional part. The fourth value is a + * constant coded as a 14-bit signed fixed-point number with 4 bits for the + * fractional part. + * + * The values in table order give the following colorspace translation: * G = 1.164 * Y - 0.391 * U - 0.813 * V + 135 * R = 1.164 * Y + 1.596 * V - 222 * B = 1.164 * Y + 2.018 * U + 276 |