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@jannau.net>
Signed-off-by: Ronald S. Bultje <rsbultje@gmail.com>
(cherry picked from commit f366256215)
