x264 - beandog's mostly dvds multimedia wiki

====== x264 ======

  * [[Handbrake]]

  * [[http://dev.beandog.org/x264_preset_reference.html|x264 preset reference]]
  * [[http://www.x264bluray.com/|Authoring a professional Blu-ray Disc with x264]]
  * [[http://mewiki.project357.com/wiki/X264_Settings|x264 Settings]]
  * [[http://en.wikipedia.org/wiki/H.264/MPEG-4_AVC|Wikipedia: H264]]
  * [[http://www.streaminglearningcenter.com/articles/understanding-h264-encoding-parameters---profiles-and-levels.html|Understanding H.264 Encoding Parameters - Profiles and Levels]]
  * [[http://mmmash.blogspot.com/2013/03/x264-motion-estimation-method-comparison.html|X264 - Motion Estimation Method- Comparison]] - I like this one. :)

=== h264 levels ===

DVDs max out at high 3.1.  You don't need 3.2 on DVDs because that is the first level that accepts 720p.

Blu-ray at high 4.1.  You can go higher if you want, it's your preference. :)

=== h264 levels: comparison ===

  * "Main" adds
    * CABAC Entropy Coding ([[http://en.wikipedia.org/wiki/CABAC|link]])
    * Interlaced Coding (PicAFF, MBAFF)
    * B slices

  * "High" adds 
    * 4:0:0 Monochrome
    * 8x8 vs 4x4 Transform Adaptivity
    * Quantization Scaling Matrices
    * Separate Cb and Cr QP control


=== mtune ===

Keep it simple (for DVDs): use ''film'' or ''animation''.  For **old** movies or sources that have artifacts already, use ''grain'' or you risk making it even worse.

=== Choosing a preset ===

Short answer: just use medium, and tweak settings somewhere else.

Choose the preset that you can stand waiting for. :)

=== Two-pass encoding ===

Use a two-pass encode if you want to meet a specific filesize or constant bitrate.

=== preset comparison gains ===

  * [[https://trac.ffmpeg.org/wiki/Encode/H.264]]

  * medium to slow, 5 to 10% quality gain
  * slow to slower, 5%
  * slower to veryslow, 3%
  * veryslow to placebo, 1%

=== Animation ===

  * [[http://x264dev.multimedia.cx/archives/102|Encoding animation]] - good read for overview of challenges.

"All of this combines to make animation at first glance deceptively easy–but in reality quite difficult–to encode."  So true!

His tests on x264

<code>
x264 (r1206)
Video format: H.264/AVC High Profile
Settings: –preset placebo –tune ssim –rc-lookahead 250, two-pass
</code>

**Note:** Don't use ''animation'' tune on CGI.

=== motion estimation comparison ===

See [[http://forum.doom9.org/showthread.php?p=693742#post693742|this forum post]] on an excellent visual comparison between mostion estimation settings.

For quick reference, here's what the x264 presets use:

  * diamond (dia): ultrafast, superfast
  * hexagon (hex): veryfast, faster, fast, medium
  * uneven multi-hexagon (umh): slow, slower, veryslow
  * exhaustive (tesa): placebo
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