$headers is a variable set in the context of other functions (we don't
use the "local" keyword in our scripts, so those variables are global).
Currently, when checking for AVFoundation/AVFoundation.h, the actual
enabled header is math.h.
Similarly, when testing for QuartzCore/CoreImage.h, the actual enabled
header is CoreGraphics/CoreGraphics.h.
This is completely broken and may be the reason why these checks are
made in random places.
On ARM platforms, accessing the PMU registers requires special user
access permissions. Since there is no other way to get accurate timers,
the current implementation of timers in FFmpeg rely on these registers.
Unfortunately, enabling user access to these registers on Linux is not
trivial, and generally involve compiling a random and unreliable github
kernel module, or patching somehow your kernel.
Such module is very unlikely to reach the upstream anytime soon. Quoting
Robin Murphin from ARM:
> Say you do give userspace direct access to the PMU; now run two or more
> programs at once that believe they can use the counters for their own
> "minimal-overhead" profiling. Have fun interpreting those results...
>
> And that's not even getting into the implications of scheduling across
> different CPUs, CPUidle, etc. where the PMU state is completely beyond
> userspace's control. In general, the plan to provide userspace with
> something which might happen to just about work in a few corner cases,
> but is meaningless, misleading or downright broken in all others, is to
> never do so.
As a result, the alternative is to use the Performance Monitoring Linux
API which makes use of these registers internally (assuming the PMU of
your ARM board is supported in the kernel, which is definitely not a
given...).
While the Linux API is obviously cross platform, it does have a
significant overhead which needs to be taken into account. As a result,
that mode is only weakly enabled on ARM platforms exclusively.
Note on the non flexibility of the implementation: the timers (native
FFmpeg vs Linux API) are selected at compilation time to prevent the
need of function calls, which would result in a negative impact on the
cycle counters.
This simplifies incoming SDL related changes by removing potential
mismatching states of sdl and sdl2 variables. Since a component can have
all kind of states (such as unset, enabled, disabled or requested),
keeping these variables in sync manually in random places is not robust.
This avoids having to use pseudo relocations.
The version script used for exporting functions is skipped as soon
as the set of object files contains symbols marked with dllexport,
therefore we need to use makedef to produce the full list of symbols
to be exported.
Signed-off-by: Martin Storsjö <martin@martin.st>
The toolchain for this target is unmaintained since many years.
While it has been continuously build tested on fate, it hasn't
actually been tested at runtime since many, many years (and back
then, only a few codecs in libavcodec were tested).
So far, keeping support for it has been mostly effortless, but
the compiler does seem to have issues with dllimported data symbols,
ending up as internal compiler errors in some cases. Instead of
jumping through further hoops to work around that, just remove the
target.
Signed-off-by: Martin Storsjö <martin@martin.st>
This patch makes the libvmaf filter use pkg-config to detect
and link to libvmaf.
Signed-off-by: Ashish Singh <ashk43712@gmail.com>
Signed-off-by: Ronald S. Bultje <rsbultje@gmail.com>
This applies a specific fixup to some Bluray streams which contain
redundant PPSs modifying irrelevant parameters of the stream which
confuse other transformations which require correct extradata.
A new single global PPS is created, and all of the redundant PPSs
within the stream are removed.
If using the winstore compat library, a fallback LoadLibrary
function does exist, that only calls LoadPackagedLibrary though
(which doesn't work for dynamically loading d3d11 DLLs).
Therefore explicitly check the targeted API family instead.
Make this check a reusable HAVE_* component which other parts
of the libraries can check when necessary as well.
Signed-off-by: Martin Storsjö <martin@martin.st>
Merged from Libav commit 4d330da006fe48178.
Works with VAAPI, VDPAU, DXVA2 and D3D11VA.
Signed-off-by: Liu, Kaixuan <kaixuan.liu@intel.com>
Signed-off-by: Jun Zhao <jun.zhao@intel.com>
Reviewed-by: Steven Liu <lingjiujianke@gmail.com>
Signed-off-by: Mark Thompson <sw@jkqxz.net>
