Enable CDEF filter for 4:2:2

Add missing logic to map CDEF direction for chroma planes.

AWCY results on derf-720p-422 at the default speed show a 9.9% decrease
in encoding speed:

   PSNR | PSNR Cb | PSNR Cr | PSNR HVS |    SSIM | MS SSIM | CIEDE 2000
-2.5572 |  0.4582 | -1.0744 |  -2.0057 | -0.1799 | -1.0506 |    -2.9736

src/cdef.rs

@@ -521,6 +521,8 @@ pub fn cdef_filter_superblock<T: Pixel, U: Pixel>(
  let local_pri_strength;
  let local_sec_strength;
  let mut local_damping: i32 = cdef_damping + coeff_shift;
+ // See `Cdef_Uv_Dir` constant lookup table in Section 7.15.1
+ // <https://aomediacodec.github.io/av1-spec/#cdef-block-process>
  let local_dir = if p == 0 {
  local_pri_strength =
  adjust_strength(cdef_pri_y_strength << coeff_shift, var);
@@ -535,7 +537,11 @@ pub fn cdef_filter_superblock<T: Pixel, U: Pixel>(
  local_sec_strength = cdef_sec_uv_strength << coeff_shift;
  local_damping -= 1;
  if cdef_pri_uv_strength != 0 {
- dir as usize
+ if xdec != ydec {
+ [7, 0, 2, 4, 5, 6, 6, 6][dir as usize]
+ } else {
+ dir as usize
+ }
  } else {
  0
  }

src/encoder.rs

@@ -242,9 +242,7 @@ impl Sequence {
  enable_ref_frame_mvs: false,
  enable_warped_motion: false,
  enable_superres: false,
- enable_cdef: config.speed_settings.cdef
- && config.chroma_sampling != ChromaSampling::Cs422
- && enable_restoration_filters,
+ enable_cdef: config.speed_settings.cdef && enable_restoration_filters,
  enable_restoration: config.speed_settings.lrf
  && config.chroma_sampling != ChromaSampling::Cs422
  && enable_restoration_filters,