Feature Selection

Commands getvcp, setvcp, and vcpinfo operate on a single VCP feature or (as of release 1.3.0) on multiple VCP features. Additionally, getvcp and vcpinfo can specify a named group of features.

The feature-code argument to vcpinfo, getvcp, and setvcp is a hexadecimal feature number, with or without a leading "x" or "0x", for example:

$ ddcutil getvcp 10
$ ddcutil vcpinfo x10
$ ddcutil getvcp 0x10

The feature-group argument to getvcp and vcpinfo is a named collection of features.
The most useful are:

Name Description
KNOWN  feature codes defined in MCCS
SCAN  scan all feature codes x00..xff
COLOR  color related features
PROFILE  features saved by dumpvcp (subset of COLOR)
TABLE  features of type Table

For example:

$ ddcutil getvcp known

There are many more feature groups. Most were created to help analyze the Monitor Control Command Set specification, and are not of general interest. For a complete list of feature groups, use option --help --verbose.

The following options subset a feature-group:

Option: --no-table

Exclude table type feature codes. This applies when a feature group is specfied, unless it is the TABLE feature group. It does not apply when a single feature code is specified. This is the default.

Option: --show-table

Include table type feature codes in all contexts.

Option: --show-table

Features of type Table exist only in Monitor Control Command Spec Version 3.0, which no known monitor has implemented. Performing getvcp on a feature of type Table which does not exist is costly in terms of elapsed time. Therefore, Table type features are excluded from all feature groups except for group SCAN, which tries to read every possible feature code except for those known to be write-only, and group TABLE, as that would be nonsensical.

This option causes such features to be included in all feature groups.

Option: --rw

Include only feature codes that are read-write.

Option: --ro

Include only feature codes that are read-only.

Option: --wo

Include only feature codes that are write-only. Applies only to vcpinfo.