h264: use avpriv_request_sample for chroma_format_idc
doxygen: Add a number of missing function parameter descriptions
doxygen: Replace @parblock syntax with manual linebreaks

@parblock is only supported in very recent Doxygen versions.
Merge commit '614b9e4db8f3d7c23fc0410fc04745a727a82f4e'

* commit '614b9e4db8f3d7c23fc0410fc04745a727a82f4e':
  h264: use avpriv_request_sample for chroma_format_idc

Conflicts:
	libavcodec/h264_ps.c

Merged-by: Michael Niedermayer <michaelni@gmx.at>
Merge commit '4d7ab5cfebef91820af2933ef2f622ea598e6b53'

* commit '4d7ab5cfebef91820af2933ef2f622ea598e6b53':
  doxygen: Add a number of missing function parameter descriptions

Conflicts:
	libavformat/avformat.h

Merged-by: Michael Niedermayer <michaelni@gmx.at>
Merge remote-tracking branch 'qatar/master'

* qatar/master:
  doxygen: Replace @parblock syntax with manual linebreaks

Merged-by: Michael Niedermayer <michaelni@gmx.at>
avformat/bink: Check return value of av_add_index_entry()

Fixes null pointer dereference
Fixes: cdbf15cbd0a27cee958dd0b8800e452e-signal_sigsegv_737991_2083_cov_317652874_LBSTART.BIK
Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>