This will prevent conflicts e.g. in code that deals with both h264 and
hevc.

The code does not depend on the h264 decoder anymore and only needs
information from h264_ps

This field (which the spec calls max_num_ref_frames) must be less than
or equal to MaxDpbFrames, which is at most 16.

The PS parsing code is independent from the decoder, so it makes more
sense for it to have its own separate header.

The SVQ3 decoder has been decoupled from the H.264 decoder, so it can
now use its own data type.

Move the NAL unit types into it. This will allow to stop including the
whole decoder-specific h264dec.h in some code that is unrelated to the
decoder and only needs some enum values.

This is more consistent with the naming of other decoders.

Right now this code is mixed with selecting the next output frame. Move
it to a separate function called from h264_field_start(), which is a
more appropriate place for this.

This is a more appropriate place for it.

Doing this after ff_thread_finish_setup() is called is invalid and can
conflict with reads from the other thread.

While the value of those variables will be constant for the whole frame,
they are only used in two functions called from slice header decoding.
Moving them to the per-slice context allows us to make the H264Context
passed to slice_header_parse() constant.

Copy them into the decoder-global context in field_start(). This avoids
modifying the decoder-global context during bitstream parsing.

Avoid unnecessary modification of the decoder-global state in per-slice
code.

There is no bitstream parsing in that block and messing with
decoder-global state is not something that belongs into header parsing.

Nothing else in this function depends on the value of current_slice,
except for two validity checks. Those checks are also moved out of
slice_header_parse().

Replace the decoder-global nal_unit_type/nal_ref_idc variables with the
per-NAL ones. The decoder-global ones still cannot be removed because
they are used by hwaccels.

* commit 'e3c9041cfe2e6526802255583d27abf9a921863e':
  h264: allocate some tables per slice contexts, not threads

Merged-by: Clément Bœsch <clement@stupeflix.com>

* commit 'e0652795292223f8bc8e5bac019c1fca7323d23c':
  h264: remove an artificial restriction on the number of slice threads

Tested with multiple runs of fate-h264 THREADS=50 THREAD_TYPE=slice

Merged-by: Clément Bœsch <clement@stupeflix.com>

It has no use afterwards and freeing it before calling ff_flac_parse_picture()
may help prevent OOM issues on memory constrained scenarios.

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

Allocate the memory needed for the decoded data rather than the
encoded data.

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

phase_shift and phase_mask is removed
generally exact_rational=on is faster than exact_rational=off

Signed-off-by: Muhammad Faiz <mfcc64@gmail.com>

Signed-off-by: Paul B Mahol <onemda@gmail.com>
Signed-off-by: Vittorio Giovara <vittorio.giovara@gmail.com>

Signed-off-by: Paul B Mahol <onemda@gmail.com>
Signed-off-by: Vittorio Giovara <vittorio.giovara@gmail.com>

Signed-off-by: Lou Logan <lou@lrcd.com>

Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

Fixes packet pts of samples which contain ctts entries with count <= 0.

* commit '4fd34e639d15b44e02686c9b4ef58c9c3c9b0a69':
  h264: remove pointless setting of some variables in loop_filter

Merged-by: Clément Bœsch <clement@stupeflix.com>

* commit '9c858ce33fa9b94ebc320dd9d9fa423e708e90cc':
  h264: remove a pointless comment

Merged-by: Clément Bœsch <clement@stupeflix.com>

* commit 'b77fffa127663028169c5ed543956af4b9496c29':
  h264: make slice threading work with deblocking_filter=1

again label, and SLICE_SINGLETHREAD error handling are preserved as that
SLICE_SINGLETHREAD can be raised on a remaining case.

slice_context_count is also kept since it's still in use.

Merged-by: Clément Bœsch <clement@stupeflix.com>

* commit '370ddc7b38d6b27b54fc2f5ee5f3dd9506f8c7c8':
  h264: remove H264Context.pict_type

Merged-by: Clément Bœsch <clement@stupeflix.com>

* commit '56087ec0a29314d1860f6f0e6f40fbb9b40feccd':
  h264: drop a pointless indirection

Merged-by: Clément Bœsch <clement@stupeflix.com>

Fixes audiotoolbox decoding of QDMC and QDM2.

* commit '0e7772c5e4f1b31e2a3dda714ba4f89b1cca644a':
  h264: remove unused H264SliceContext.rbsp_buffer

Merged-by: Clément Bœsch <clement@stupeflix.com>

* commit '7f045c4429e91688f1f2335dd347203431901c06':
  h264: merge ff_h264_free_context() into h264_decode_end()

Merged-by: Clément Bœsch <clement@stupeflix.com>

* commit '99c554efc8b09c3f1bb2fb41c3da5431085f7470':
  h264: eliminate low_delay

ff_print_debug_info2() is adjusted to allow a NULL pointer as low_delay.
It's only useful for MPEG codecs with the exception of H264.

Merged-by: Clément Bœsch <clement@stupeflix.com>

And sets frames pkt_dts to AV_NOPTS_VALUE as we do not want lavc/utils
to overwrite the field with incorrect values as the decoder is
asynchronous.

Fixes error:
libavcodec/videotoolbox.c:511:18: error: implicit declaration of function
'CMVideoFormatDescriptionCreateFromH264ParameterSets' is invalid in C99

This was added in 10.9:
https://developer.apple.com/reference/coremedia/1489818-cmvideoformatdescriptioncreatefr?language=objc

Signed-off-by: Marton Balint <cus@passwd.hu>

Signed-off-by: Marton Balint <cus@passwd.hu>

Signed-off-by: Thomas Mundt <loudmax@yahoo.de>
Signed-off-by: James Almer <jamrial@gmail.com>

The caps_internal field has moved without major bump and direct
access causes crashes, found when testing 3.1

Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>