tools/edid/established_timings.py

# Copyright 2014 The Chromium OS Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.


"""Provides the EstablishedTimings class with methods for parsing info.

EstablishedTimings information is found in bytes 23h-25h of the base EDID.
"""

import tools


_timings = [
    [0x800000, '720x400 @ 70 Hz'],
    [0x400000, '720x400 @ 88 Hz'],
    [0x200000, '640x480 @ 60 Hz'],
    [0x100000, '640x480 @ 67 Hz'],
    [0x80000, '640x480 @ 72 Hz'],
    [0x40000, '640x480 @ 75 Hz'],
    [0x20000, '800x600 @ 56 Hz'],
    [0x10000, '800x600 @ 60 Hz'],
    [0x8000, '800x600 @ 72 Hz'],
    [0x4000, '800x600 @ 75 Hz'],
    [0x2000, '832x624 @ 75 Hz'],
    [0x1000, '1024x768 @ 87 Hz, interlaced (1024x768i)'],
    [0x800, '1024x768 @ 60 Hz'],
    [0x400, '1024x768 @ 72 Hz'],
    [0x200, '1024x768 @ 75 Hz'],
    [0x100, '1280x1024 @ 75 Hz'],
    [0x80, '1152x870 @ 75 Hz (Apple Macintosh II)'],
    [0x40, 'Manufacturer specific display mode 1'],
    [0x20, 'Manufacturer specific display mode 2'],
    [0x10, 'Manufacturer specific display mode 3'],
    [0x8, 'Manufacturer specific display mode 4'],
    [0x4, 'Manufacturer specific display mode 5'],
    [0x2, 'Manufacturer specific display mode 6'],
    [0x1, 'Manufacturer specific display mode 7']
]


class EstablishedTimings(object):
  """Identifies and returns a list of supported Established Timings."""

  def __init__(self, edid):
    """Creates an EstablishedTimings object.

    Args:
      edid: The EDID being analyzed.
    """
    self._edid = edid

  @property
  def supported_timings(self):
    """Creates the list of supported timings.

    Returns:
      The dict of strings and bools indicating supported timings.
    """
    # Bytes 35, 36, 37
    timing_byte = ((self._edid[0x23] << 16) + (self._edid[0x24] << 8)
                   + (self._edid[0x25]))
    return tools.DictFilter(_timings, timing_byte)