[英]Is there an easy way to use x264 presets with ffmpeg in code?
我正在尝试使用ffmpeg和x264对视频进行编码。 我知道从命令行使用ffmpeg程序时,ffmpeg可以使用x264预设。 但是,在代码中使用ffmpeg进行编码时,是否可以轻松使用这些预设?
如果不是,从ffmpeg代码设置x264参数的最佳方法是什么? 是否仅使用AVCodecContext的属性? 所有的x264选项都可以通过此方法使用吗?
谢谢!
抱歉,回答太晚了,但我有相同的问题,我想分享找到的解决方案。 是的,至少在使用libav时,可以通过命令行和API传递许多x264选项(我现在无法用ffmpeg进行确认)。 通过发布avconv --help,您可以找到以下内容:
libx264 AVOptions:
-preset <string> E.V.. Set the encoding preset (cf. x264 --fullhelp)
-tune <string> E.V.. Tune the encoding params (cf. x264 --fullhelp)
-profile <string> E.V.. Set profile restrictions (cf. x264 --fullhelp)
-fastfirstpass <int> E.V.. Use fast settings when encoding first pass
-crf <float> E.V.. Select the quality for constant quality mode
-crf_max <float> E.V.. In CRF mode, prevents VBV from lowering quality beyond this point.
-qp <int> E.V.. Constant quantization parameter rate control method
-aq-mode <int> E.V.. AQ method
none E.V..
variance E.V.. Variance AQ (complexity mask)
autovariance E.V.. Auto-variance AQ (experimental)
-aq-strength <float> E.V.. AQ strength. Reduces blocking and blurring in flat and textured areas.
-psy <int> E.V.. Use psychovisual optimizations.
-psy-rd <string> E.V.. Strength of psychovisual optimization, in <psy-rd>:<psy-trellis> format.
-rc-lookahead <int> E.V.. Number of frames to look ahead for frametype and ratecontrol
-weightb <int> E.V.. Weighted prediction for B-frames.
-weightp <int> E.V.. Weighted prediction analysis method.
none E.V..
simple E.V..
smart E.V..
-ssim <int> E.V.. Calculate and print SSIM stats.
-intra-refresh <int> E.V.. Use Periodic Intra Refresh instead of IDR frames.
-b-bias <int> E.V.. Influences how often B-frames are used
-b-pyramid <int> E.V.. Keep some B-frames as references.
none E.V..
strict E.V.. Strictly hierarchical pyramid
normal E.V.. Non-strict (not Blu-ray compatible)
-mixed-refs <int> E.V.. One reference per partition, as opposed to one reference per macroblock
-8x8dct <int> E.V.. High profile 8x8 transform.
-fast-pskip <int> E.V..
-aud <int> E.V.. Use access unit delimiters.
-mbtree <int> E.V.. Use macroblock tree ratecontrol.
-deblock <string> E.V.. Loop filter parameters, in <alpha:beta> form.
-cplxblur <float> E.V.. Reduce fluctuations in QP (before curve compression)
-partitions <string> E.V.. A comma-separated list of partitions to consider. Possible values: p8x8, p4x4, b8x8, i8x8, i4x4, none, all
-direct-pred <int> E.V.. Direct MV prediction mode
none E.V..
spatial E.V..
temporal E.V..
auto E.V..
-slice-max-size <int> E.V.. Limit the size of each slice in bytes
-stats <string> E.V.. Filename for 2 pass stats
使用AVCodecContext结构时,还可以设置-rc-lookahead之类的选项,可以在AVCodecContext :: rc_lookahead中设置,但是我现在不确定-preset。
希望这可以帮助
声明:本站的技术帖子网页,遵循CC BY-SA 4.0协议,如果您需要转载,请注明本站网址或者原文地址。任何问题请咨询:yoyou2525@163.com.