doc/encoders/libx264: clarify meaning of level option

In particular, clarify that it can either be set as a field of
AVCodecContext or as an x264 option, using a different specification.

Should address trac issue:
http://trac.ffmpeg.org/ticket/3947
This commit is contained in:
Stefano Sabatini 2023-08-26 02:53:28 +02:00
parent 6f421d9d4e
commit d0f071dfe7

View File

@ -2446,6 +2446,20 @@ Quantizer curve compression factor
@item refs (@emph{ref})
Number of reference frames each P-frame can use. The range is from @var{0-16}.
@item level (@emph{level})
Set the @code{x264_param_t.i_level_idc} value in case the value is
positive, it is ignored otherwise.
This value can be set using the @code{AVCodecContext} API (e.g. by
setting the @code{AVCodecContext} value directly), and is specified as
an integer mapped on a corresponding level (e.g. the value 31 maps
to H.264 level IDC "3.1", as defined in the @code{x264_levels}
table). It is ignored when set to a non positive value.
Alternatively it can be set as a private option, overriding the value
set in @code{AVCodecContext}, and in this case must be specified as
the level IDC identifier (e.g. "3.1"), as defined by H.264 Annex A.
@item sc_threshold (@emph{scenecut})
Sets the threshold for the scene change detection.