Man / CODEC固有オプション / -x264encopts / pass
2010-03-15 (月) 11:31:15更新

pass=<1-3>:2または 3パスモードの指定。


Enable 2 or 3-pass mode. It is recommended to always encode in 2 or 3-pass mode as it leads to a better bit distribution and improves overall quality.

1 first pass
2 second pass (of two pass encoding)
3 Nth pass (second and third passes of three pass encoding)

Here is how it works, and how to use it:
The first pass (pass=1) collects statistics on the video and writes them to a file. You might want to deactivate some CPU-hungry options, apart from the ones that are on by default.
In two pass mode, the second pass (pass=2) reads the statistics file and bases ratecontrol decisions on it.
In three pass mode, the second pass (pass=3, that is not a typo) does both:
It first reads the statistics, then overwrites them. You can use all encoding options, except very CPU-hungry options.
The third pass (pass=3) is the same as the second pass, except that it has the second pass' statistics to work from. You can use all encoding options, including CPU-hungry ones.
The first pass may use either average bitrate or constant quantizer.
ABR is recommended, since it does not require guessing a quantizer. Subsequent passes are ABR, and must specify bitrate.

・MEncoder dev-CVS-060314-20:27-4.0.1 (C) 2000-2006 MPlayer Team
・x264 core:45 svn-467


2または 3パスモードの指定。

1 1st パス
2 2nd パス (または2パスエンコード)
3 Nth パス (3pass エンコードの 2nd と 3rd パス)

1st pass(pass=1)は映像の統計を取ってファイルに書き込む。 CPU負荷の高いオプションは使わなくて良いが、デフォルトでonのものは使う事。
2nd pass(pass=2)はstats(※統計)ファイルを読み込み、これを基にビットレート配分をコントロールする。
3rd pass(pass=3)は2nd passと同じだが、2nd passの統計を使用する。CPU負荷の高いオプションを含めて、全てのエンコードオプションが使える。 1st pass はABRでも固定quantizerでも良いが、quantizerを推測する必要がないので、ABRの方が望ましい。



  • pass=1(1st)
  • pass=3(2nd)
  • pass=3(Nth)
  • pass=3(Nth)
  • pass=2(Final)