[FFmpeg-devel] [PATCH 2/3] arm: vp9mc: Load only 12 pixels in the 4 pixel wide horizontal filter

[Michael Niedermayer]

Hi Janne

On Thu, Dec 19, 2024 at 10:12:22PM +0100, Janne Grunau wrote:
> This reduces the amount the horizontal filters read beyond the filter
> width to a consistent 1 pixel. The data is not used so this is usually
> not noticeable. It becomes a problem when the application allocates
> frame buffers only for the aligned picture size and the end of it is at
> a page boundary. This happens for picture sizes which are a multiple of
> the page size like 1280x640. The frame buffer allocation is based on
> its most likely done via mmap + MAP_ANONYMOUS so start and end of the
> buffer are page aligned and the previous and next page are not
> necessarily mapped.
> This mirrors the aarch64 change.
> 
> Signed-off-by: Janne Grunau <janne-ffmpeg at jannau.net>
> ---
>  libavcodec/arm/vp9mc_neon.S | 13 ++++++++++---
>  1 file changed, 10 insertions(+), 3 deletions(-)

tested on qemu-arm (assuming the standard fate and qemu covers this)

thx

[...]
-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

"I am not trying to be anyone's saviour, I'm trying to think about the
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