[FFmpeg-user] Scene detection

Roger Pack rogerdpack2 at gmail.com
Fri Oct 28 20:34:41 CEST 2011

> Also I assume libx264 uses something like this to decide on its
> i-frame's (without having to do 2-pass)... ?

It apperas that libx264 does some scene cut detection internally, to
look for i-frames,
viz vlc's man page:

      --sout-x264-scenecut=<integer [-1 .. 100]>
                                 Extra I-frames aggressivity
          Scene-cut detection. Controls how aggressively to insert extra
          I-frames. With small values of scenecut, the codec often has to force
          an I-frame when it would exceed keyint. Good values of scenecut may
          find a better location for the I-frame. Large values use more
          I-frames than necessary, thus wasting bits. -1 disables scene-cut
          detection, so I-frames are inserted only every other keyint frames,
          which probably leads to ugly encoding artifacts. Range 1 to 100.

I wonder why 2 pass is so much better then...

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