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API to provide info on the monitor in use

Subscribe to API to provide info on the monitor in use 3 posts, 3 voices

 
Jun 26, 2017 7:01pm
Avatar André Timmermans (100) 184 posts

I am currently modifying KinoAmp to provide pan & scan to 4:3 or 16:9, but it would be best to be able to pan & scan to the aspect ratio of the monitor since there are a lot of possibilities (4:3, 16:9, 16:10, 2.21:1, …).

My immediate usage case for an API is to obtain aspect ratio information on the monitor used or maybe its preferred resolution (assuming square pixels).

For multiple displays, display selection tools could offer info such as name and (prefered/current?) resolution for each possible display.

 
Jun 27, 2017 9:20am
Avatar Chris Hall (132) 2306 posts

Surely this already exists in the form of EDID support? The screen resolution is then set to the native resolution of the display. KinoAmp then knows the screen resolution. Or am I missing something?

 
Jun 27, 2017 10:13am
Avatar Jeffrey Lee (213) 4856 posts

There’s a lot of information in the EDID which ScreenModes currently ignores/throws away:

  • Monitor dimensions & aspect ratio
  • Colour temperature / gamma info (could be useful for auto-configuration of the OS’s gamma table)
  • Aspect ratios for individual screen modes, e.g. you can have the same mode available in both 4:3 and 16:9 versions (although I think it can be a bit hit-and-miss whether monitors actually pay attention to this information)
  • Precise frame rate information, or whether a mode is interlaced (you can get this information in a roundabout way via Service_ModeExtension, but if there are multiple modes with similar parameters there’s no way of controlling which one is used)

You can get the monitor’s preferred mode from Service_MonitorLeadTranslation, but there’s always the possibility that something else is overriding the result, so a way of getting it directly from ScreenModes might be desirable (and at some point I’d expect ScreenModes to make sure the mode returned by Service_MonitorLeadTranslation is actually supported by the video hardware, so in the future it might not always be the monitor’s preferred mode that’s returned)

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  • AndrĂ© Timmermans (100)
  • Chris Hall (132)
  • Jeffrey Lee (213)

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