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How to Specify Extra Encoder Parameters

Melvin Dichoso
January 26, 20162 mins read

It is possible to override or add new encoder parameters using the syntax &ex:key:value. It is definitely NOT recommended for everyone to use this functionality – in the matter of fact, unless you are very technical and have a very good reason to fiddle with this  (and you probably do not) then leave the settings alone. (NOTE: We do not provide support assistance for extra encoder parameters)

For x264:

Most parameters supported by the x264 encoder can be found here:

X264 Settings

Simply apply the &ex: syntax instead of — syntax.

For example, “&ex:profile:main” will apply main profile restrictions. “&ex:profile:main&ex:tune:animation” will add tuning for animation content.

Not all x264 options may be supported and please note that any settings you make will override settings from the GUI. So for example if you set “&ex:keyint:60” then you will have a max GOP interval of 60 frames no matter what setting you may have set in the GUI. 

For Intel Quick Sync:

What follows are the parameters that we currently support for Quick Sync. Take note that some parameters behave differently or are ignored depending on the Rate Control Method set.

H264 Profile

Param Name: profile
66 – Baseline
77 – Main
88 – Extended
100 – High

Example: &ex:profile:100

GOP Pic Size (Key Frame Interval)

Param Name: goppicsize
Usage: The number of frames in a group of pictures which also indicates how often a key frame is inserted.

Example: &ex:goppicsize:120

Rate Control Method

Param Name: rc_method
1 – Constant Bitrate (CBR)
2 – Variable Bitrate (VBR)
3 – Constant Quality Parameter (CQP)

Example: &ex:rc_method:3

Target Kbps

Param Name: targetkbps
In CBR – The bitrate used
In VBR – The target bitrate

Example: &ex:targetkbps:3000

Max Kbps

Param Name: maxkbps
In VBR: The max bitrate allowed

Constant Quality Parameter Settings

Usage: Only for CQP
Param Names:
qpi – target quality for i-frames
qpp – target quality for p-frames
qpb – target quality for b-frames

Should normally be set to have the same values for simplicity. Value provided will approximate the quality of x264’s crf setting but with a bigger file size.

Example: &ex:qpi:23&ex:qpp:23&ex:qpb:23

Melvin Dichoso

A basketball junkie, blogger, headphone enthusiast, aspiring chef, and traveler wannabe. Does social media and various other stuff for XSplit.More from this Author