* commit '59c70227':
  pthread_frame: use atomics for frame progress

This commit is a noop, see b6587421Merged-by: Clément Bœsch <u@pkh.me>

* commit '64a31b28':
  pthread_frame: use atomics for PerThreadContext.state

This commit is a noop, see 74926269Merged-by: Clément Bœsch <u@pkh.me>

* commit 'db273325':
  pthread_frame: use a thread-safe way for signalling threads to die

This commit is a noop, see 4845f072Merged-by: Clément Bœsch <u@pkh.me>

* commit '8385ba53':
  mmaldec: convert to stdatomic
Merged-by: Clément Bœsch <u@pkh.me>

* commit '3a165c18':
  v4l2: convert to stdatomic
Merged-by: Clément Bœsch <u@pkh.me>

* commit '27079a42':
  buffer: convert to stdatomic
Merged-by: Clément Bœsch <u@pkh.me>

USE_ATOMICS is only set if there is no thread implementation enabled, in
which case you can't expect any lock mechanism from FFmpeg.

This is also conflicting with the incoming use of stdatomic.

* commit 'eb34d403':
  Add a compat dummy stdatomic.h used when threading is disabled
  Add a compat stdatomic.h implementation based on pthreads
  Add a compat stdatomic.h implementation based on suncc atomics
  Add a compat stdatomic.h implementation based on windows atomics
  Add a compat stdatomic.h implementation based on GCC atomics

This merge is a noop, see:
  41e891e8 Add a compat dummy stdatomic.h used when threading is disabled
  74b5f108 Add a compat stdatomic.h implementation based on pthreads
  70faadc8 Add a compat stdatomic.h implementation based on suncc atomics
  c91e72ed Add a compat stdatomic.h implementation based on windows atomics
  3359eede Add a compat stdatomic.h implementation based on GCC atomics
Merged-by: Clément Bœsch <u@pkh.me>

* commit '13f5d2bf':
  configure: check for stdatomic.h

This commit is a noop, see 6a4e2428Merged-by: Clément Bœsch <u@pkh.me>

* commit 'b015872c':
  huffyuvdsp: Enable the altivec code for PPC little-endian as well

This commit is a noop, see 902ce2a6 and
libavcodec/ppc/lossless_videodsp_altivec.c
Merged-by: Clément Bœsch <u@pkh.me>

* commit '1d25a869':
  huffyuvdsp: Reenable PPC optimizations

This commit is a noop, see 6596b349Merged-by: Clément Bœsch <u@pkh.me>

* commit '22c3ab18':
  checkasm: Add test for huffyuvdsp add_bytes

huffyuvdsp is renamed to llviddsp to be consistent with our codebase.

Note: af607b7e wasn't actually required for this test since this
commit is not actually testing huffyuvdsp.
Merged-by: Clément Bœsch <u@pkh.me>

Only the pixel format is required in that init function. This will also
simplify the incoming merge.

* commit '27085d1b':
  avconv: only retry decoding on actual decoding errors
Merged-by: Clément Bœsch <u@pkh.me>

* commit 'f6772e9b':
  avconv: make sure the filtergraph is freed on init failure

This commit is a noop, see 16abc10bMerged-by: Clément Bœsch <u@pkh.me>

* commit 'd10102d2':
  avconv: set the encoding framerate when the output is CFR

This commit is a noop, see 8db301deMerged-by: Clément Bœsch <u@pkh.me>

* commit '5bf2454e':
  h264dec: support broken files with mp4 extradata/annex b data

This commit is a noop, see 93b89868

The sample pointed out on
https://github.com/HandBrake/HandBrake/issues/339 decodes fine in
FFmpeg.
Merged-by: Clément Bœsch <u@pkh.me>

* commit '2124711b':
  hwcontext_vaapi: add a quirk for the missing MemoryType attribute

This commit is a noop, see 775a8477Merged-by: Clément Bœsch <u@pkh.me>

* commit 'b57e38f5':
  ac3dsp: x86: Replace inline asm for in-decoder downmixing with standalone asm
Merged-by: Clément Bœsch <u@pkh.me>

* commit 'a9ba5959':
  ac3dsp: Add some special-case handling for the C downmix function
Merged-by: Clément Bœsch <u@pkh.me>

* commit '43717469':
  ac3dsp: Reverse matrix in/out order in downmix()
Merged-by: Clément Bœsch <u@pkh.me>

use the option set by user
Reported-by: Lancelot Lai <laihy23@gmail.com>
Signed-off-by: Steven Liu <lq@chinaffmpeg.org>

Signed-off-by: Matthias Hunstock <atze@fem.tu-ilmenau.de>
Signed-off-by: Marton Balint <cus@passwd.hu>

Signed-off-by: Matthias Hunstock <atze@fem.tu-ilmenau.de>
Signed-off-by: Marton Balint <cus@passwd.hu>

fix the wrong comments for av_hwdevice_ctx_alloc()
Signed-off-by: Jun Zhao <jun.zhao@intel.com>
Signed-off-by: Mark Thompson <sw@jkqxz.net>

Reviewed-by: wm4 <nfxjfg@googlemail.com>
Signed-off-by: Marton Balint <cus@passwd.hu>

Should fix ticket #6252
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>

Reviewed-by: Henrik Gramner <henrik@gramner.com>
Signed-off-by: James Almer <jamrial@gmail.com>

* commit '8ea35af7':
  avio: add a new flag for marking streams seekable by timestamp
Merged-by: James Almer <jamrial@gmail.com>

* commit '75c1db61':
  avio: cosmetics, prettify AVIO_SEEKABLE_NORMAL
Merged-by: James Almer <jamrial@gmail.com>

* commit '83548fe8':
  lavf: fix usage of AVIOContext.seekable
Merged-by: James Almer <jamrial@gmail.com>

Fixes: runtime error: shift exponent 255 is too large for 32-bit type 'unsigned int'
Fixes: 894/clusterfuzz-testcase-4841537823309824

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