configure: Move x11grab option to a more suitable place in the help output
configure: Move list of external libs to a separate variable

Signed-off-by: Mans Rullgard <mans@mansr.com>
configure: List external libs used using print_enabled()

This cuts some lines from the script as well as the output and
simplifies maintenance.

Signed-off-by: Mans Rullgard <mans@mansr.com>
dsputil_alpha.h: Add missing stddef.h header to fix standalone compilation
vorbisdec: Error on bark_map_size equal to 0.

The value is used to calculate output LSP curve and a division by zero
and out of array accesses would occur.

CVE-2013-0894

CC: libav-stable@libav.org

Reported-by: Dale Curtis <dalecurtis@chromium.org>
Found-by: inferno@chromium.org
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
Signed-off-by: Luca Barbato <lu_zero@gentoo.org>
vorbisdec: cosmetics

Use the commonly used "if (!var)" instead of "if (var == 0)".
vorbisdec: Add missing checks

Rate and order must not be 0 even if the specification does not say that
explicitly.
vorbisdec: Accept 0 amplitude_bits

The specification does not prevent an encoder to write the amplitude 0
as 0 amplitude_bits.

Our get_bits() implementation might not support a zero sized read
properly, thus the additional branch.