H.264 Settings

This topic contains details for encoding settings related to H.264 video outputs.

Encoding recommendations

In addition to settings found on this page, you may want to include the following general video settings.

crf

crf:Integer

API Versions: V2

Parent: outputs

Valid Values: 1-51

Compatible Job Types: VOD

Example: 26

Description:

CRF is a bitrate-control setting, and sets a constant ratefactor. This is closely related to constant quantizer encoding, though CRF mode generally achieves better compression than constant Q encoding by reducing the quantizer quality on "less important" frames. Read more about crf.

The Zencoder Quality setting determines an appropriate CRF for a given video. So if you set both Quality and CRF, the CRF setting will override Quality.

Valid values are 0-51, with lower values being better quality. Generally speaking, you shouldn't have to go below 16; 16 is nearly lossless for most files. Around 24 usually looks pretty good. Around 35 looks pretty compressed.

{
  "input": "s3://zencodertesting/test.mov",
  "outputs": [
    {
      "crf": "26"
    }
  ]
}