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marqs85 / ossc

Open Source Scan Converter
http://junkerhq.net/xrgb/index.php/OSSC
GNU General Public License v3.0
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Suggestion for OSSC Pro on how to distinguish resolutions with identical timings #77

Closed Darry77 closed 3 years ago

Darry77 commented 3 years ago

Sorry if this completely impossible or if this has already been suggested, but I wonder if it would feasible to implement a detection algorithm to automatically switch from 640x400@70Hz to 720x400@70Hz VGA mode sampling by adapting a contrast detection algorithm, as used in digital photography https://en.wikipedia.org/wiki/Autofocus#Contrast_detection ?

IMHO, this would not need to run on every line of every frame, but only long enough to achieve a conclusive match and only often enough to ensure switching when necessary . Some sort of debouncing method to avoid switching continuously would probably be needed to .

Again sorry, if I am talking nonsense or suggesting the impossible .

marqs85 commented 3 years ago

It's not impossible, but I'd prefer something more robust such as hsync length based detection like 640x480 vs 720x480. Unfortunately 640x400@70Hz and 720x400@70Hz timings are indeed identical (aside from different H. active) as far as I know so there's no reliable indicator which mode is used.

marqs85 commented 3 years ago

Closing since this is a feature request for OSSC Pro.