How to request hardware resolution NATIVE of the main monitor in Windows?

Question

I need to find the “best” or native resolution for the connected LCD monitor under Windows (which I will then install programmatically and know how to do it.) Let me reiterate that I do not need permission from the current Windows, nor do I have to worry about CRT / projectors .

I saw how it works with this program, so I know that this is possible, despite the skeptics: http://www.entechtaiwan.com/util/moninfo.shtm

It would be better to talk directly with the monitor and request EDID information. However, I saw that it is cached in the registry and will not have a problem with extracting it from HKLM \ SYSTEM \ CurrentControlSet \ Enum \ DISPLAY, but cannot figure out how to match the data with the current main monitor.

I found this program in C: http://www.tech-archive.net/Archive/Development/microsoft.public.development.device.drivers/2004-08/0294.html and a similar python program: http: // www .koders.com / python / fid7FCCE3C908F376DC62F06CAD9B11C6D7C1CFA78F.aspx

Unfortunately, I have a lot of problems converting the C program to python, since the corresponding code does not seem to be in the win32all modules. I would try to compile it, but did not have disk space for a large compiler and have not used C for many years. I am a bit out of my element with ctypes.

My plan B will use EnumDisplaySettings () to find the highest resolution value and set it to this. On the PC I tried, it gives the correct answers, but this can be problematic.

I would prefer a solution in python, but maybe someone could help me change the program in C to spit out the resolution and compile it. Thanks in advance.

Update:

I found a potential solution. Now I read WMI to find a monitor that is available (not offline), grab its PNP device identifier and read the EDID from the registry in the subkey with the identification value. Then I parse the data for bytes 38 and 39 and compute. Not very clean, but I get results. If this is a reasonable way to do this, I will close this question, thanks.

Answer 1

It was decided to abandon conversations directly with the monitor and instead parse the EDID information stored in the cache in the registry. This code is not perfect, but it works:

import win32api as api, win32con as con, pywintypes import win32com.client _objWMIService = win32com.client.Dispatch('WbemScripting.SWbemLocator') _objSWbemServices = _objWMIService.ConnectServer('.', 'root\\cimv2') wmiquery = _objSWbemServices.ExecQuery # get_regval(regkey) is simple registry reading function. def get_monitor_res(): dtd = 54 # start byte of detailed timing desc. try: # get PNP id to find EDID in registry for monitor in wmiquery('Select * from Win32_DesktopMonitor'): # http://msdn.microsoft.com/en-us/library/aa394122%28VS.85%29.aspx if monitor.Availability in (3, 7, 13, 14, 15, 16): # connected curres = (monitor.ScreenWidth, monitor.ScreenHeight) print 'DEBUG: Current monitor resolution from WMI: %s' % (curres,) regkey = ('HKLM\\SYSTEM\\CurrentControlSet\\Enum\\' + monitor.PNPDeviceID + '\\Device Parameters\\EDID') edid = get_regval(regkey) if edid: print 'DEBUG: EDID Version: %s.%s' % (edid[18], edid[19]) # upper nibble of byte x 2^8 combined with full byte hres = ((edid[dtd+4] >> 4) << 8) | edid[dtd+2] vres = ((edid[dtd+7] >> 4) << 8) | edid[dtd+5] print 'DEBUG: EDID DTD0: ' + str((hres, vres)) res = (hres, vres) break # give up on first success else: raise RuntimeError, 'EDID not found in registry' except (RuntimeError, Exception) as err: print 'ERROR: %s.' % err return res