configure: prettify atomics handling.

Add simpler names and a shorthand for native atomics (as opposed to
pthreads fallback).
configure: Check for the atomic.h functions used in the suncc atomics header

The "suncc" atomics implementation uses a suncc specific memory
barrier, but also relies on a few atomic functions from atomic.h,
that are not suncc specific but specific to solaris. This made
the current implementation fail on suncc on linux.
avfiltergraph: check for sws opts being non-NULL before using them.

Avoid snprintfing a NULL pointer.

CC: libav-stable@libav.org
clang: use -fsantize=address and -fsanitize=thread

The previous syntax is deprecated.
matroska: Update the available size after lace parsing

Fix heap-buffer-overflow in matroska_parse_block for
corrupted real media in mkv files.

CC: libav-stable@libav.org

Signed-off-by: Luca Barbato <lu_zero@gentoo.org>
matroska: fix a corner case in ebml-lace parsing

Make sure we notice when the lace_size[n] is a negative value.

CC: libav-stable@libav.org
matroska: pass the lace size to the matroska_parse_rm_audio

Each lace must be independent according to the specification.

Fix heap-buffer-overflow in matroska_parse_block for
corrupted real media in mkv files.

Stricter check than fc43c19a567aa945398dccb491d972c11ec2a065

CC: libav-stable@libav.org
doc: Fix best_nb_channells typo

Signed-off-by: Peter Meerwald <p.meerwald@bct-electronic.com>
Signed-off-by: Anton Khirnov <anton@khirnov.net>
opt: check the return values of av_get_token for ENOMEM.
avfiltergraph: set deprecated filter_count.
lavf: make sure stream probe data gets freed.

Reported-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
CC: libav-stable@libav.org
dfa: check for invalid access in decode_wdlt().

This can happen when the number of skipped lines is not consistent with
the number of coded lines.

Reported-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
CC: libav-stable@libav.org
id3v2: pad the APIC packets as required by lavc.

Reported-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
CC: libav-stable@libav.org
bmv: check for len being valid in bmv_decode_frame().

It can be 0 or -1 for invalid files, which may result in invalid memory
access.

Reported-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
CC: libav-stable@libav.org
xmv: check audio track parameters validity.

Reported-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
CC: libav-stable@libav.org
xmv: do not leak memory in the error paths in xmv_read_header()

CC: libav-stable@libav.org
img2: Add j2k file extension for JPEG 2000

Signed-off-by: Diego Biurrun <diego@biurrun.de>
pixdesc/pixfmt: Add XYZ colorspace for XYZ 12-bit values

Signed-off-by: Diego Biurrun <diego@biurrun.de>
libopenjpeg: Add support for XYZ colorspace, found in DCINEMA frames

Signed-off-by: Diego Biurrun <diego@biurrun.de>
dynamic loading of shared faac library