error_resilience: add required headers.
Merge remote-tracking branch 'qatar/master'

* qatar/master:
  error_resilience: add required headers.

Merged-by: Michael Niedermayer <michaelni@gmx.at>
doc/examples: do not allocate AVFrame directly.

The size of the AVFrame structure is not part of the ABI;
it can grow with later versions. Therefore, applications
are not supposed to allocate AVFrame directly, they are
supposed to use avcodec_alloc_frame() instead.
doc/codecs: simple sub_charenc option documentation.
Only set accelerated arm fft functions if fft is enabled.

Fixes lavc compilation (linking) for configurations without fft.

Reported-by: tyler wear
Tested-by: Gavin Kinsey
eval: print() support

This allows printing values via av_log from expressions.

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
fate: add print() to the tests of eval

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>