After some testing with the code linked in my original, I managed to figure it out:
from ctypes import windll, byref, Structure, WinError, POINTER, WINFUNCTYPE
from ctypes.wintypes import BOOL, HMONITOR, HDC, RECT, LPARAM, DWORD, BYTE, WCHAR, HANDLE
_MONITORENUMPROC = WINFUNCTYPE(BOOL, HMONITOR, HDC, POINTER(RECT), LPARAM)
class _PHYSICAL_MONITOR(Structure):
_fields_ = [('handle', HANDLE),
('description', WCHAR * 128)]
def _iter_physical_monitors(close_handles=True):
"""Iterates physical monitors.
The handles are closed automatically whenever the iterator is advanced.
This means that the iterator should always be fully exhausted!
If you want to keep handles e.g. because you need to store all of them and
use them later, set `close_handles` to False and close them manually."""
def callback(hmonitor, hdc, lprect, lparam):
monitors.append(HMONITOR(hmonitor))
return True
monitors = []
if not windll.user32.EnumDisplayMonitors(None, None, _MONITORENUMPROC(callback), None):
raise WinError('EnumDisplayMonitors failed')
for monitor in monitors:
# Get physical monitor count
count = DWORD()
if not windll.dxva2.GetNumberOfPhysicalMonitorsFromHMONITOR(monitor, byref(count)):
raise WinError()
# Get physical monitor handles
physical_array = (_PHYSICAL_MONITOR * count.value)()
if not windll.dxva2.GetPhysicalMonitorsFromHMONITOR(monitor, count.value, physical_array):
raise WinError()
for physical in physical_array:
yield physical.handle
if close_handles:
if not windll.dxva2.DestroyPhysicalMonitor(physical.handle):
raise WinError()
def set_vcp_feature(monitor, code, value):
"""Sends a DDC command to the specified monitor.
See this link for a list of commands:
ftp://ftp.cis.nctu.edu.tw/pub/csie/Software/X11/private/VeSaSpEcS/VESA_Document_Center_Monitor_Interface/mccsV3.pdf
"""
if not windll.dxva2.SetVCPFeature(HANDLE(monitor), BYTE(code), DWORD(value)):
raise WinError()
# Switch to HDMI, wait for the user to press return and then back to DP
for handle in _iter_physical_monitors():
set_vcp_feature(handle, 0x60, 0x11) #Change input to HDMI
input()
set_vcp_feature(handle, 0x60, 0x0F) #Change input to DisplayPort
Turns out the vcp code for input commands is 0x60, and from there the values can be determined quite easily, they are as followed:
0x01: D-sub/VGA, 0x03: DVI, 0x11 or 0x04 depending on the brand: HDMI, 0x0F: DisplayPort
