This fixes dxva2 detection (i.e. correctly realizes that it isn't
available) for WinRT, where dxva2api.h does exist, but these definitions
are omitted (when targeting the API subsets).

Ideally we should rather check for e.g. DXVA2_ConfigPictureDecode,
but configure might fail to find that definition due to _WIN32_WINNT
not being set to the right value during configure. (libavcodec/dxva2.h
manually overrides the _WIN32_WINNT define.)

This allows removing hardcoded --disable-dxva2 from such build
configurations.
Signed-off-by: Martin Storsjö <martin@martin.st>

Signed-off-by: Martin Storsjö <martin@martin.st>

Signed-off-by: Martin Storsjö <martin@martin.st>

Fixes build with some mingw-w64 versions, that have got the header
but not the interface declaration.
Signed-off-by: Martin Storsjö <martin@martin.st>

Signed-off-by: Martin Storsjö <martin@martin.st>

Signed-off-by: Martin Storsjö <martin@martin.st>

mpz_import and mpz_export were added in GMP 4.1, in 2002.

This simplifies the DH code by clarifying that it only uses pure
bignum functions, no other parts of nettle/hogweed.
Signed-off-by: Martin Storsjö <martin@martin.st>

Signed-off-by: Martin Storsjö <martin@martin.st>

Partially based on the work of Timo Rothenpieler <timo@rothenpieler.org>
Signed-off-by: Luca Barbato <lu_zero@gentoo.org>

The old logic required an explicit clearing of the lists first and was
prone to overflow the DXVA2 struct in some circumstances.
Signed-off-by: Luca Barbato <lu_zero@gentoo.org>

Signed-off-by: Luca Barbato <lu_zero@gentoo.org>

If avio_read fails, the buffer can contain uninitialized data.

This fixes 'Conditional jump or move depends on uninitialised value(s)'
valgrind warnings, and addresses a few memleaks.
Signed-off-by: Andreas Cadhalpun <Andreas.Cadhalpun@googlemail.com>
Signed-off-by: Vittorio Giovara <vittorio.giovara@gmail.com>
Signed-off-by: Luca Barbato <lu_zero@gentoo.org>

Signed-off-by: Luca Barbato <lu_zero@gentoo.org>

In this case the mov demuxer can return a large number of empty packets.
Signed-off-by: Andreas Cadhalpun <Andreas.Cadhalpun@googlemail.com>
Signed-off-by: Luca Barbato <lu_zero@gentoo.org>

Otherwise the loop can take a lot of time if num_descr is very large.
Signed-off-by: Andreas Cadhalpun <Andreas.Cadhalpun@googlemail.com>
Signed-off-by: Luca Barbato <lu_zero@gentoo.org>

It can be reallocated.

CC: libav-stable@libav.org

Signed-off-by: Andreas Cadhalpun <Andreas.Cadhalpun@googlemail.com>
Signed-off-by: Luca Barbato <lu_zero@gentoo.org>

CC: libav-stable@libav.org