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diff --git a/doc/encoders.texi b/doc/encoders.texi index 3b6f7df..315c901 100644 --- a/doc/encoders.texi +++ b/doc/encoders.texi @@ -834,4 +834,92 @@ by commas (,). See kvazaar documentation for a list of options. @end table +@section QSV encoders + +The family of Intel QuickSync Video encoders (MPEG-2, H.264 and HEVC) + +The ratecontrol method is selected as follows: + +@itemize @bullet +@item +When @option{global_quality} is specified, a quality-based mode is used. +Specifically this means either +@itemize @minus +@item +@var{CQP} - constant quantizer scale, when the @option{qscale} codec flag is +also set (the @option{-qscale} avconv option). + +@item +@var{LA_ICQ} - intelligent constant quality with lookahead, when the +@option{la_depth} option is also set. + +@item +@var{ICQ} -- intelligent constant quality otherwise. +@end itemize + +@item +Otherwise, a bitrate-based mode is used. For all of those, you should specify at +least the desired average bitrate with the @option{b} option. +@itemize @minus +@item +@var{LA} - VBR with lookahead, when the @option{la_depth} option is specified. + +@item +@var{VCM} - video conferencing mode, when the @option{vcm} option is set. + +@item +@var{CBR} - constant bitrate, when @option{maxrate} is specified and equal to +the average bitrate. + +@item +@var{VBR} - variable bitrate, when @option{maxrate} is specified, but is higher +than the average bitrate. + +@item +@var{AVBR} - average VBR mode, when @option{maxrate} is not specified. This mode +is further configured by the @option{avbr_accuracy} and +@option{avbr_convergence} options. +@end itemize +@end itemize + +Note that depending on your system, a different mode than the one you specified +may be selected by the encoder. Set the verbosity level to @var{verbose} or +higher to see the actual settings used by the QSV runtime. + +Additional libavcodec global options are mapped to MSDK options as follows: + +@itemize +@item +@option{g/gop_size} -> @option{GopPicSize} + +@item +@option{bf/max_b_frames}+1 -> @option{GopRefDist} + +@item +@option{rc_init_occupancy/rc_initial_buffer_occupancy} -> +@option{InitialDelayInKB} + +@item +@option{slices} -> @option{NumSlice} + +@item +@option{refs} -> @option{NumRefFrame} + +@item +@option{b_strategy/b_frame_strategy} -> @option{BRefType} + +@item +@option{cgop/CLOSED_GOP} codec flag -> @option{GopOptFlag} + +@item +For the @var{CQP} mode, the @option{i_qfactor/i_qoffset} and +@option{b_qfactor/b_qoffset} set the difference between @var{QPP} and @var{QPI}, +and @var{QPP} and @var{QPB} respectively. + +@item +Setting the @option{coder} option to the value @var{vlc} will make the H.264 +encoder use CAVLC instead of CABAC. + +@end itemize + @c man end VIDEO ENCODERS |