There is no longer any need for a list of them at runtime, because
decoders now carry the pointers to their associated hwaccels internally.
The file containing external declarations is now used to make the list
of hwaccels for configure.

This removes the dependency that hardware pixel formats previously had on
AVHWAccel instances, meaning only those which actually do something need
exist after this patch.

Also updates avcodec_default_get_format() to be able to choose hardware
formats if either a matching device has been supplied or no additional
external configuration is required, and avcodec_get_hw_frames_parameters()
to use the hardware config rather than searching the old hwaccel list.

The FF_CODEC_CAP_HWACCEL_REQUIRE_CLASS mechanism is deleted because it
no longer does anything (the codec already contains the pointers to the
matching hwaccels).

This includes a pointer to the associated hwaccel for decoders using
hwaccels - these will be used later to implement the hwaccel setup
without needing a global list.

Also added is a new file listing all hwaccels as external declarations -
this will be used later to generate the hwaccel list at configure time.

Fixes: chromium-773637/clusterfuzz-testcase-minimized-6418078673141760

Found-by: ossfuzz/chromium
Reviewed-by: James Almer <jamrial@gmail.com>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

Fixes: runtime error: signed integer overflow: -2143827186 - 7404944 cannot be represented in type 'int'
Fixes: 4354/clusterfuzz-testcase-minimized-4671122764201984

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpegSigned-off-by: Michael Niedermayer <michael@niedermayer.cc>

Prevents a segfault when alloc fails.
Signed-off-by: Derek Buitenhuis <derek.buitenhuis@gmail.com>

Reviewed-by: Timo Rothenpieler <timo@rothenpieler.org>

Drivers can support a format for surfaces without also supporting it for
images, so we can't assume that sw_format is usable for transfer.  This
would previously hit an assert in cases where it isn't.

Fixes NULL dereference during alloc failure.
Signed-off-by: Derek Buitenhuis <derek.buitenhuis@gmail.com>

Signed-off-by: Paul B Mahol <onemda@gmail.com>

Signed-off-by: Rostislav Pehlivanov <atomnuker@gmail.com>

Also makes it more robust than using volatiles.
Signed-off-by: Rostislav Pehlivanov <atomnuker@gmail.com>

Signed-off-by: Rostislav Pehlivanov <atomnuker@gmail.com>

Reviewed-by: Michael Niedermayer <michael@niedermayer.cc>
Signed-off-by: James Almer <jamrial@gmail.com>

Reviewed-by: Michael Niedermayer <michael@niedermayer.cc>
Signed-off-by: James Almer <jamrial@gmail.com>

decode rgtc1 block in gray8 picture

Makes the uninit function re-entrable, which can be a common case
when an API user first tries to initialize its context, fails, and
then finally unrefs the AVHWDevice.

Fixes a crash reported by sm2345 on IRC.

The commit b7c16a3f ("x86: fft: Port to
cpuflags") breaks the opus decoder in ffmpeg when compiling for 3dnow. The
output is audible, but there's a lot of noise.

The reason for the breakage is that the commit unintentionally changed the
INTERL macro so that it is empty when compiling for 3dnow. This patch
fixes it.
Signed-off-by: Mikulas Patocka <mikulas@twibright.com>
Signed-off-by: James Almer <jamrial@gmail.com>

device_uninit can be called twice if device_init fails.

This is helpful to know what device has actually been used.

Both are autodetected, and their dependency on cuda is checked
elsewhere.

Fixes ticket #6849.
Reviewed-by: Philip Langdale <philipl@overt.org>
Signed-off-by: James Almer <jamrial@gmail.com>

Also fix a typo and fill hashes and dates.

This was added for compatibility with libav, by leaving a space for
formats added in libav to be merged.  Since that feature has been
removed, we don't need a gap here.
Reviewed-by: Michael Niedermayer <michael@niedermayer.cc>

* commit '136e7cf6':
  qsv/hevcdec: Load hw plugin by default on non-windows os
Merged-by: Mark Thompson <sw@jkqxz.net>

This patch fixes the following error when compiling mplayer with libopus.

libavcodec/libopusdec.c: In function 'libopus_decode_init':
libavcodec/libopusdec.c:130:27: error: implicit declaration of function 'ff_exp10'; did you mean 'ff_exp2fi'? [-Werror=implicit-function-declaration]
         double gain_lin = ff_exp10(gain_db / (20.0 * 256));
                           ^~~~~~~~
                           ff_exp2fi
Signed-off-by: Mikulas Patocka <mikulas@twibright.com>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

Use correct index into streams
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

Reviewed-by: 刘歧 <lq@chinaffmpeg.org>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

Fixes: signed integer overflow: 2147483598 + 64 cannot be represented in type 'int'
Fixes: 4337/clusterfuzz-testcase-minimized-6192658616680448

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpegSigned-off-by: Michael Niedermayer <michael@niedermayer.cc>

Signed-off-by: James Almer <jamrial@gmail.com>

nvdec will not produce odd width/height output, and while this is
basically never an issue with most codecs, due to internal alignment
requirements, you can get odd sized jpegs.

If an odd-sized jpeg is encountered, nvdec will actually round down
internally and produce output that is slightly smaller. This isn't
the end of the world, as long as you know the output size doesn't
match the original image resolution.

However, with an hwaccel, we don't know. The decoder controls
the reported output size and the hwaccel cannot change it. I was
able to trigger an error in mpv where it tries to copy the output
surface as part of rendering and triggers a cuda error because
cuda knows the output frame is smaller than expected.

To fix this, we can round up the configured width/height passed
to nvdec so that the frames are always at least as large as the
decoder's reported size, and data can be copied out safely.

In this particular jpeg case, you end up with a blank (green) line
at the bottom due to nvdec refusing to decode the last line, but
the behaviour matches cuviddec, so it's as good as you're going to
get.

Signed-off-by: James Almer <jamrial@gmail.com>

This is a bit more robust in case of OOM.
Signed-off-by: James Almer <jamrial@gmail.com>

Signed-off-by: Dale Curtis <dalecurtis@chromium.org>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>