The directional intra predictors either don't care about order (dc, h,
dc_left, tm), or they prefer inverted order (vr, dr, hd). This allows
more efficient SIMD implementations.
before:
./ffmpeg -v 0 -nostats -i ~/samples/vp9/etv.webm -f null - 16.29s user 0.02s system 99% cpu 16.323 total
./ffmpeg -v 0 -nostats -i ~/samples/vp9/etv.webm -f null - 16.32s user 0.01s system 99% cpu 16.351 total
./ffmpeg -v 0 -nostats -i ~/samples/vp9/etv.webm -f null - 16.27s user 0.05s system 99% cpu 16.335 total
after:
./ffmpeg -v 0 -nostats -i ~/samples/vp9/etv.webm -f null - 15.22s user 0.03s system 99% cpu 15.257 total
./ffmpeg -v 0 -nostats -i ~/samples/vp9/etv.webm -f null - 15.20s user 0.02s system 99% cpu 15.237 total
./ffmpeg -v 0 -nostats -i ~/samples/vp9/etv.webm -f null - 15.19s user 0.02s system 99% cpu 15.227 total
The memset following the memcpy was silencing the problem since
re-writing that same byte.
Fixes CID1108597, CID1108598, (16x16)
CID1108599, CID1108600, (8x8)
CID1108601, CID1108602 (32x32)
Signed-off-by: Clément Bœsch <u@pkh.me>