This adds a new API, which allows the API user to query the required
AVHWFramesContext parameters. This also reduces code duplication across
the hwaccels by introducing ff_decode_get_hw_frames_ctx(), which uses
the new API function. It takes care of initializing the hw_frames_ctx
if needed, and does additional error handling and API usage checking.

Support for VDA and Cuvid missing.
Signed-off-by: Anton Khirnov <anton@khirnov.net>

According to the MediaSDK documentation the idr_interval value has
a different meaning depending on the codec:

    0 in H264 means make every I-frame IDR, in HEVC it means to have
    it only at the beginning.

    1 in H264 means every other I-frame is not-IDR, in HEVC it means
    that every I-frame is IDR.

Keep the behaviour consistent between the two encoders by increasing
by 1 internally the idr_interval value for HEVC.

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

This fixes building with armasm64 (when run through gas-preprocessor).
Signed-off-by: Martin Storsjö <martin@martin.st>

The extra space got included as part of the expansion of ELF, which
later interfered with gas-preprocessor which earlier only stripped out
leftover lines starting with '#' if the line started with that char.
Signed-off-by: Martin Storsjö <martin@martin.st>

Fixes the MPEG-2 failure with --disable-error-resilience.

It is wrong to pass no arguments to a macro that expects one argument
and some compilers complain.

Support for this device has been removed in the Linux kernel since v2.6.37.
dv1394 has been superseded by libiec61883 which is functionally equivalent.
Signed-off-by: Josh de Kock <josh@itanimul.li>
Signed-off-by: Diego Biurrun <diego@biurrun.de>

The libavformat API is not suitable for exporting output devices as muxers.
Some practical problems are e.g. lack of timing/synchronization mechanisms
or interaction with output-specific features.

Fixes: 559/clusterfuzz-testcase-6424225917173760
Bug-Id: CVE-2017-7862
CC: libav-stable@libav.org

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/targets/ffmpegSigned-off-by: Michael Niedermayer <michael@niedermayer.cc>
(cherry picked from commit 8c2ea303)
Signed-off-by: Diego Biurrun <diego@biurrun.de>

Since this machine type is 5 chars while the existing ones only
were 3 (which the regexp assumed), the regexp has to be extended
a little.
Signed-off-by: Martin Storsjö <martin@martin.st>

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

On X86 windows, asflags weren't actually ever used for anything,
since assembling used x86asflags instead, and that flags list
had -DPIC already.

This fixes building shared libraries with clang for arm/aarch64
windows. (This wasn't an issue when in msvc mode before, since
we don't try to enable pic at all there, since the msvc armasm
assembler fails on our pic constructs there.)
Signed-off-by: Martin Storsjö <martin@martin.st>

We skipped adding it to cflags for mingw/cygwin configurations
where the compiler either complains loudly or even errors out;
do the same for target_os=win32, for the case when building with
clang in msvc mode.

This wasn't needed for the actual msvc before, since msvc uses
msvc_common_flags to filter out this flag from cflags.
When building with clang in msvc mode, no such filter is used.

This fixes building shared libraries with clang in msvc mode.
Signed-off-by: Martin Storsjö <martin@martin.st>

It does not represent a header but a complete system capability.

Also use that new capability to simplify bktr header checks.

This feature was never used for anything.

These extralibs are set by pkg-config already.

fork() is never used conditionally.

It should be sys/soundcard.h nowadays.

libgsm never installed more than a single header, the headers installed into
the gsm/ subdirectory by some distros are private. Who started this nonsense
is a mystery, but it got cargo-culted around ever since.

We already rely on just mmap() in other places.

It is detected as a part of the ID3D11VideoDecoder check.

It is detected as a part of the libdl check.

The variable lists are for variables whose values end up in output files.

This proprietary Unix flavor dropped from the face of the earth more
than a decade ago. Nothing of value was lost.