Fixes PAL8 to YUV conversion.

Signed-off-by: Ronald S. Bultje <rsbultje@gmail.com>

This fixes integer multiplication overflows in RGB48 output
(vertical) scaling as detected by IOC. What happens is that for
certain types of filters (lanczos, spline, bicubic), the
intermediate sum of coefficients in the middle of a filter can
be larger than the fixed-point equivalent of 1.0, even if the
final sum is 1.0. This is fine and we support that.

However, at frame edges, initFilter() will merge the coefficients
for the off-screen pixels into the top or bottom pixel, such as
to emulate edge extension. This means that suddenly, a single
coefficient can be larger than the fixed-point equivalent of
1.0, which the vertical scaling routines do not support.

Therefore, remove the merging of coefficients for edges for
the vertical scaling filter, and instead add edge detection
to the scaler itself so that it copies the pointers (not data)
for the edges (i.e. it uses line[0] for line[-1] as well), so
that a single coefficient is never larger than the fixed-point
equivalent of 1.0.

This fixes the same overflow as in the RGB48/16-bit YUV scaling;
some filters can overflow both negatively and positively (e.g.
spline/lanczos), so we bias a signed integer so it's "half signed"
and "half unsigned", and can cover overflows in both directions
while maintaining full 31-bit depth.
Signed-off-by: Mans Rullgard <mans@mansr.com>

We're shifting individual components (8-bit, unsigned) left by 24,
so making them unsigned should give the same results without the
overflow.
Signed-off-by: Ronald S. Bultje <rsbultje@gmail.com>

Add a macro to shorten the if condition.

For certain types of filters where the intermediate sum of coefficients
can go above the fixed-point equivalent of 1.0 in the middle of a filter,
the sum of a 31-bit calculation can overflow in both directions and can
thus not be represented in a 32-bit signed or unsigned integer. To work
around this, we subtract 0x40000000 from a signed integer base, so that
we're halfway signed/unsigned, which makes it fit even if it overflows.
After the filter finishes, we add the scaled bias back after a shift.

We use the same trick for 16-bit bpc YUV output routines.
Signed-off-by: Mans Rullgard <mans@mansr.com>

Signed-off-by: Mans Rullgard <mans@mansr.com>

Signed-off-by: Mans Rullgard <mans@mansr.com>

These semicolons cause invalid empty top-level declarations.
Signed-off-by: Mans Rullgard <mans@mansr.com>

this file uses the M_PI macro since
4e74187d, so include the correct header
directly.
Signed-off-by: Reinhard Tartler <siretart@tauware.de>

As old bits are shifted out of the accumulator, they cause signed
overflows when they reach the end.  Making the variable unsigned fixes
this.
Signed-off-by: Mans Rullgard <mans@mansr.com>

This was removed erroneously in
046f081b. This define still is
necessary for getting MAP_ANONYMOUS defined on linux/glibc,
despite the define reshuffling done in that commit.

Without MAP_ANONYMOUS defined, the mprotect calls for setting the
generated mmx2 scaler code pages executable are left out, causing
crashes if that codepath is chosen.

This patch fixes scaling from 192x144 to 320x240 with
-sws_flags fast_bilinear, which crashes on linux at the
moment.
Signed-off-by: Martin Storsjö <martin@martin.st>

isGray() is left as a FIXME for later.

Although gcc guarantees 16 byte stack alignment, threads under WinXP
don't appear to be guaranteed to start stack aligned.  So fix the
alignment.
Signed-off-by: Ronald S. Bultje <rsbultje@gmail.com>

The issue had been introduced in
c4356536Signed-off-by: Luca Barbato <lu_zero@gentoo.org>

Altivec does unaligned reads from this buffer in
hscale_altivec_real(), and can thus read up to 16 bytes beyond
the end of the buffer. Therefore, add an extra 16 bytes of
padding at the end of the conversion buffer.

This fixes fate-lavfi-pixfmts_scale on AltiVec-enabled builds
under valgrind.
Signed-off-by: Ronald S. Bultje <rsbultje@gmail.com>

The vertical scaler handles 2 rows at a time and thus requires
alignment by 2, or else it'll read invalid memory and result in
corrupt output.

This fixes assembling using "nasm".

Also implement MMX/MMX2 versions and SSE4 versions.

Signed-off-by: Ronald S. Bultje <rsbultje@gmail.com>

Signed-off-by: Ronald S. Bultje <rsbultje@gmail.com>

Signed-off-by: Ronald S. Bultje <rsbultje@gmail.com>

Signed-off-by: Mans Rullgard <mans@mansr.com>

Signed-off-by: Janne Grunau <janne-libav@jannau.net>