Test the pixel format querying within libswscale.

Fixes a gcc warning:
libswscale/slice.c:178:56: warning: assignment discards 'const' qualifier from pointer target type [-Wdiscarded-qualifiers]

Fixes warnings like the following:
libswscale/input.c:951:13: warning: ‘planar_rgb14be_to_a’ defined but not used

Fixes: CID1396263
Fixes: CID1396271
Signed-off-by: NMichael Niedermayer <michael@niedermayer.cc>

Configure checks if the ebx register can be used for asm and it has to
be saved if and only if this is not the case.
Without this the build fails when configuring with --toolchain=hardened
--disable-pic on i386 using gcc 4.8:
error: PIC register clobbered by '%ebx' in 'asm'

In that case gcc 4.8 reserves the ebx register for the GOT needed for
PIE, so it can't be used in asm directly.
Reviewed-by: NMichael Niedermayer <michael@niedermayer.cc>
Signed-off-by: NAndreas Cadhalpun <Andreas.Cadhalpun@googlemail.com>

Found-by: NAndreas Cadhalpun <andreas.cadhalpun@googlemail.com>
Signed-off-by: NMichael Niedermayer <michael@niedermayer.cc>

Based on 19be5fb7 by Luca Barbato.

Signed-off-by: NMichael Niedermayer <michael@niedermayer.cc>

Signed-off-by: NMichael Niedermayer <michael@niedermayer.cc>

Signed-off-by: NMichael Niedermayer <michael@niedermayer.cc>

Signed-off-by: NMichael Niedermayer <michael@niedermayer.cc>

Signed-off-by: NMichael Niedermayer <michael@niedermayer.cc>

Found-by: Luca Barbato
Signed-off-by: NMichael Niedermayer <michael@niedermayer.cc>

Signed-off-by: NMichael Niedermayer <michael@niedermayer.cc>

Signed-off-by: NMichael Niedermayer <michael@niedermayer.cc>

Signed-off-by: NPedro Arthur <bygrandao@gmail.com>

Signed-off-by: NMichael Niedermayer <michael@niedermayer.cc>

Signed-off-by: NMichael Niedermayer <michael@niedermayer.cc>

Signed-off-by: NMichael Niedermayer <michael@niedermayer.cc>

Signed-off-by: NMichael Niedermayer <michael@niedermayer.cc>

Signed-off-by: NMichael Niedermayer <michael@niedermayer.cc>

Signed-off-by: NMichael Niedermayer <michael@niedermayer.cc>

Signed-off-by: NMichael Niedermayer <michael@niedermayer.cc>

Signed-off-by: NMichael Niedermayer <michael@niedermayer.cc>

They are internal symbols that should not be exported.

based on a patch by Andreas Cadhalpun <Andreas.Cadhalpun@googlemail.com>
Signed-off-by: NDiego Biurrun <diego@biurrun.de>

It is an internal swscale symbol and thus should not be exported.
Signed-off-by: NAndreas Cadhalpun <Andreas.Cadhalpun@googlemail.com>
Signed-off-by: NDiego Biurrun <diego@biurrun.de>

This reverts commit 1df908f3. The expected
performance improvements are essentially non-existent.

Signed-off-by: NAnton Khirnov <anton@khirnov.net>

This patch addresses Trac ticket #5570. The optimized functions are in file
libswscale/ppc/input_vsx.c. Each optimized function name is a concatenation of the
corresponding name in libswscale/input.c with suffix _vsx.
Signed-off-by: NMichael Niedermayer <michael@niedermayer.cc>

See merge commit '39d6d361'.