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#!/usr/bin/env python3
from collections import namedtuple
import struct
import Xlib.display
class Edid:
# Modified from the original source: https://github.com/jojonas/pyedid/blob/master/edid.py
_STRUCT_FORMAT = ( ">" # big-endian
"8s" # constant header (8 bytes)
"H" # manufacturer id (2 bytes)
"H" # product id (2 bytes)
"I" # serial number (4 bytes)
"B" # manufactoring week (1 byte)
"B" # manufactoring year (1 byte)
"B" # edid version (1 byte)
"B" # edid revision (1 byte)
"B" # video input type (1 byte)
"B" # horizontal size in cm (1 byte)
"B" # vertical size in cm (1 byte)
"B" # display gamma (1 byte)
"B" # supported features (1 byte)
"10s" # color characteristics (10 bytes)
"H" # supported timings (2 bytes)
"B" # reserved timing (1 byte)
"16s" # EDID supported timings (16 bytes)
"18s" # detailed timing block 1 (18 bytes)
"18s" # detailed timing block 2 (18 bytes)
"18s" # detailed timing block 3 (18 bytes)
"18s" # detailed timing block 4 (18 bytes)
"B" # extension flag (1 byte)
"B" ) # checksum (1 byte)
_TIMINGS = {
0: (1280, 1024, 75.),
1: (1024, 768, 75.),
2: (1024, 768, 72.),
3: (1024, 768, 60.),
4: (1024, 768, 87.),
5: ( 832, 624, 75.),
6: ( 800, 600, 75.),
7: ( 800, 600, 70.),
8: ( 800, 600, 60.),
9: ( 800, 600, 56.),
10:( 640, 480, 75.),
11:( 640, 480, 72.),
12:( 640, 480, 67.),
13:( 640, 480, 60.),
14:( 720, 400, 88.),
15:( 720, 400, 70.),
}
_ASPECT_RATIOS = {
0b00: (16, 10),
0b01: ( 4, 3),
0b10: ( 5, 4),
0b11: (16, 9),
}
_RawEdid = namedtuple("RawEdid", ("header", "manu_id", "prod_id", "serial_no", "manu_week",
"manu_year", "edid_version", "edid_revision", "input_type",
"width", "height", "gamma", "features", "color",
"timings_supported", "timings_reserved", "timings_edid",
"timing_1", "timing_2", "timing_3", "timing_4", "extension",
"checksum"))
def __init__(self, bytes=None):
if bytes is not None:
self._parse_edid(bytes)
def _parse_edid(self, bytes):
if struct.calcsize(self._STRUCT_FORMAT) != 128:
raise ValueError("Wrong edid size.")
if sum(map(int, bytes)) % 256 != 0:
raise ValueError("Checksum mismatch.")
tuple = struct.unpack(self._STRUCT_FORMAT, bytes)
raw_edid = self._RawEdid(*tuple)
if raw_edid.header != b'\x00\xff\xff\xff\xff\xff\xff\x00':
raise ValueError("Invalid header.")
self.raw = bytes
self.manufacturer = raw_edid.manu_id
self.product = raw_edid.prod_id
self.year = raw_edid.manu_year + 1990
self.edid_version = "%d.%d" % (raw_edid.edid_version, raw_edid.edid_revision)
self.type = "digital" if (raw_edid.input_type & 0xFF) else "analog"
self.width = float(raw_edid.width)
self.height = float(raw_edid.height)
self.gamma = (raw_edid.gamma+100)/100
self.dpms_standby = bool( raw_edid.features & 0xFF )
self.dpms_suspend = bool( raw_edid.features & 0x7F )
self.dpms_activeoff = bool( raw_edid.features & 0x3F )
self.resolutions = []
for i in range(16):
bit = raw_edid.timings_supported & i
if bit:
self.resolutions.append(self._TIMINGS[16-i])
for i in range(8):
bytes = raw_edid.timings_edid[2*i:2*i+2]
if bytes == b'\x01\x01':
continue
byte1, byte2 = bytes
x_res = 8*(int(byte1)+31)
aspect_ratio = self._ASPECT_RATIOS[ (byte2>>6) & 0b11 ]
y_res = int(x_res * aspect_ratio[1]/aspect_ratio[0])
rate = (int(byte2) & 0b00111111) + 60.0
self.resolutions.append((x_res, y_res, rate))
self.name = None
self.serial = None
for bytes in (raw_edid.timing_1, raw_edid.timing_2, raw_edid.timing_3, raw_edid.timing_4):
if bytes[0:2] == b'\x00\x00': # "other" descriptor
type = bytes[3]
if type in (0xFF, 0xFE, 0xFC):
buffer = bytes[5:]
buffer = buffer.partition(b"\x0a")[0]
text = buffer.decode("cp437")
if type == 0xFF:
self.serial = text
elif type == 0xFC:
self.name = text
if not self.serial:
self.serial = raw_edid.serial_no
def __repr__(self):
clsname = self.__class__.__name__
attributes = []
for name in dir(self):
if not name.startswith("_"):
value = getattr(self, name)
attributes.append("\t%s=%r" % (name, value))
return "%s(\n%s\n)" % (clsname, ", \n".join(attributes))
def get_x_displays():
# Xlib resources
d = Xlib.display.Display()
root = d.screen().root
resources = root.xrandr_get_screen_resources()._data
outputs = {}
for output in resources['outputs']:
output_info = d.xrandr_get_output_info(output, resources['config_timestamp'])._data
output_name = output_info['name']
props = d.xrandr_list_output_properties(output)
edid_data = None
# Look through the atoms (properties) of each output to see if there's one named 'EDID'
for atom in props._data['atoms']:
atom_name = d.get_atom_name(atom)
if atom_name == 'EDID':
edid_raw = d.xrandr_get_output_property(output, atom, 0, 0, 1000)._data['value']
edid_data = Edid(bytes(edid_raw)[:128])
break
outputs[output_name] = edid_data
return outputs
if __name__ == '__main__':
displays = get_x_displays()
for connection, monitor in sorted(displays.items(), key=lambda kv: kv[0]):
print(connection)
print(' ' + ("No connection or empty EDID" if monitor is None else
"{} ({})".format(monitor.name, monitor.serial)))
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