ddcutil

Announcements

16 November 2017

Release 0.8.5 contains a large number of minor enhancements and bug fixes. Users of ddcutil on 32 bit platforms and those on the Raspberry Pi should upgrade.

For a complete list of changes and bug fixes, see Release Notes. Prior announcements can be found here.

15 October 2017

Package ddcutil has been sponsored into Debian and is now included in Debian Testing. It is on track to be part of the next Debian release, which means it should eventually appear in downstream distributions such as Ubuntu. Note that only package ddcutil, containing the command line version of ddcutil, is currently in the Debian repositories. The shared library packages, including the C and Python APIs, are not yet part of Debian.

22 July 2017

Release 0.8.4 primarily contains packaging changes to meet Fedora distribution standards.

For a complete list of changes and bug fixes, see Release Notes. Prior annoucnements can be found here.

17 May 2017

Release 0.8.2 contains minor enhancements, primarily to diagnostics in the environment and interrogate commands.

For a complete list of changes and bug fixes, see Release Notes. Prior annoucnements can be found here.

05 May 2017

Release 0.8.1 is a bugfix release that addresses a segfault that can occur when scanning for USB connected monitors.

For a complete list of changes and bug fixes, see Release Notes. Prior annoucnements can be found here.

01 May 2017

Release 0.8.0 contains new features intended to address issues with particular monitors and user environments, and to improve performance

The most significant changes visible to users are:

  • If there are multiple monitors and option --async is specified, initial monitor checks are performed in separate threads. Users with multiple monitors should see significantly better startup time.
  • If a display is specified by its I2C bus number (option --bus) and option --nodetect is specified, global display detection is skipped, improving performance.
  • By default, setvcp and loadvcp now read the VCP value after it has been set, to confirm that the monitor has made the change requested.
  • Command getvcp --terse now reports VCP settings in a form that is easily machine readable.
  • The C API has been extensively revised. Many names have changed for consistency and clarity.
    (Apologies to those of you who have written applications.)

For a complete list of changes and bug fixes, see Release Notes. Prior annoucnements can be found here.

Introduction

ddcutil is a Linux program for querying and changing monitor settings, such as brightness and color levels.

ddcutil primarily uses DDC/CI (Display Data Channel Command Interface) to communicate with monitors implementing MCCS (Monitor Control Command Set) over I2C. Normally, the video driver for the monitor exposes the I2C channel as devices named /dev/i2c-n. Alternatively, there is support for monitors (such as Eizo ColorEdge displays) that implement MCCS using a USB connection. See USB Connected Monitors.

Generally speaking, any settings that can be changed by pressing buttons on the monitor can be modified by ddcutil. Examples include controlling brigtness and switching input source.

A particular use case for ddcutil, and the one that inspired its development, is as part of color profile management. Monitor calibration is relative to the monitor color settings currently in effect, e.g. red gain. ddcutil allows color related settings to be saved at the time a monitor is calibrated, and then restored when the calibration is applied.

Restrictions:

  • ddcutil does not support laptop displays, which are controlled using a special API, not I2C.
  • Nvidia's proprietary video driver may require special configuration. See Special Nvidia Driver Settings.
  • Operation with AMD's proprietary video driver fglrx requires a specially built version of ddcutil. See Building with ADL Support.
  • Reading and writing Table type features is implemented but untested. See Table Features

ddcutil is released under the GNU Public License, V2 (GPLV2). The source is hosted on Github.

General support questions are best directed the to the issue tracker on Github. Use of that forum allows everyone to benefit from individual questions and ideas. For details, see Technical Support.

Topics

Using ddcutil:

Installation and Configuration:

Other:

Author

Sanford Rockowitz rockowitz@minsoft.com