Change #260083

Comments

avcodec/x86/vvc/alf: Remove pointless counter, stride
Each luma alf block has 2*12 auxiliary coefficients associated
with it that the alf_filter functions consume; the C version
simply increments the pointers.

The x64 dsp function meanwhile does things differenty:
The vvc_alf_filter functions have three levels of loops.
The middle layer uses two counters, one of which is
just the horizontal offset xd in the current line. It is only
used for addressing these auxiliary coefficients and
yet one needs to perform work translate from it to
the coefficient offset, namely a *3 via lea and a *2 scale.
Furthermore, the base pointers of the coefficients are incremented
in the outer loop; the stride used for this is calculated
in the C wrapper functions. Furthermore, due to GPR pressure xd
is reused as loop counter for the innermost loop; the
xd from the middle loop is pushed to the stack.

Apart from the translation from horizontal offset to coefficient
offset all of the above has been done for chroma, too, although
the coefficient pointers don't get modified for them at all.

This commit changes this to just increment the pointers
after reading the relevant coefficients.

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>

Changed files

• libavcodec/x86/vvc/alf.asm
• libavcodec/x86/vvc/dsp_init.c