decoders/ir_irmp/irmp_library.py

   1 ##
   2 ## This file is part of the libsigrokdecode project.
   3 ##
   4 ## Copyright (C) 2019 Rene Staffen
   5 ##
   6 ## This program is free software; you can redistribute it and/or modify
   7 ## it under the terms of the GNU General Public License as published by
   8 ## the Free Software Foundation; either version 2 of the License, or
   9 ## (at your option) any later version.
  10 ##
  11 ## This program is distributed in the hope that it will be useful,
  12 ## but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 ## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 ## GNU General Public License for more details.
  15 ##
  16 ## You should have received a copy of the GNU General Public License
  17 ## along with this program; if not, see <http://www.gnu.org/licenses/>.
  18 ##
  19
  20 '''
  21 Python binding for the IRMP library.
  22 '''
  23
  24 import ctypes
  25 import platform
  26
  27 class IrmpLibrary:
  28     '''
  29     Library instance for an infrared protocol detector.
  30     '''
  31
  32     __usable_instance = None
  33
  34     class ResultData(ctypes.Structure):
  35         _fields_ = [
  36             ( 'protocol', ctypes.c_uint32, ),
  37             ( 'protocol_name', ctypes.c_char_p, ),
  38             ( 'address', ctypes.c_uint32, ),
  39             ( 'command', ctypes.c_uint32, ),
  40             ( 'flags', ctypes.c_uint32, ),
  41             ( 'start_sample', ctypes.c_uint32, ),
  42             ( 'end_sample', ctypes.c_uint32, ),
  43         ]
  44
  45     FLAG_REPETITION = 1 << 0
  46     FLAG_RELEASE = 1 << 1
  47
  48     def _library_filename(self):
  49         '''
  50         Determine the library filename depending on the platform.
  51         '''
  52
  53         if platform.uname()[0] == 'Linux':
  54             return 'libirmp.so'
  55         if platform.uname()[0] == 'Darwin':
  56             return 'libirmp.dylib'
  57         return 'irmp.dll'
  58
  59     def _library_setup_api(self):
  60         '''
  61         Lookup the C library's API routines. Declare their prototypes.
  62         '''
  63
  64         if not self._lib:
  65             return False
  66
  67         self._lib.irmp_get_sample_rate.restype = ctypes.c_uint32
  68         self._lib.irmp_get_sample_rate.argtypes = []
  69
  70         self._lib.irmp_reset_state.restype = None
  71         self._lib.irmp_reset_state.argtypes = []
  72
  73         self._lib.irmp_add_one_sample.restype = ctypes.c_int
  74         self._lib.irmp_add_one_sample.argtypes = [ ctypes.c_int, ]
  75
  76         if False:
  77             self._lib.irmp_detect_buffer.restype = self.ResultData
  78             self._lib.irmp_detect_buffer.argtypes = [ ctypes.POINTER(ctypes.c_uint8), ctypes.c_size_t, ]
  79
  80         self._lib.irmp_get_result_data.restype = ctypes.c_int
  81         self._lib.irmp_get_result_data.argtypes = [ ctypes.POINTER(self.ResultData), ]
  82
  83         self._lib.irmp_get_protocol_name.restype = ctypes.c_char_p
  84         self._lib.irmp_get_protocol_name.argtypes = [ ctypes.c_uint32, ]
  85
  86         # Create a result buffer that's local to the library instance.
  87         self._data = self.ResultData()
  88
  89         return True
  90
  91     def __init__(self):
  92         '''
  93         Create a library instance.
  94         '''
  95
  96         # Only create a working instance for the first invocation.
  97         # Degrade all other instances, make them fail "late" during
  98         # execution, so that users will see the errors.
  99         self._lib = None
 100         self._data = None
 101         if IrmpLibrary.__usable_instance is None:
 102             filename = self._library_filename()
 103             self._lib = ctypes.cdll.LoadLibrary(filename)
 104             self._library_setup_api()
 105             IrmpLibrary.__usable_instance = self
 106
 107     def get_sample_rate(self):
 108         if not self._lib:
 109             return None
 110         return self._lib.irmp_get_sample_rate()
 111
 112     def reset_state(self):
 113         if not self._lib:
 114             return None
 115         self._lib.irmp_reset_state()
 116
 117     def add_one_sample(self, level):
 118         if not self._lib:
 119             raise Exception("IRMP library limited to a single instance.")
 120         if not self._lib.irmp_add_one_sample(int(level)):
 121             return False
 122         self._lib.irmp_get_result_data(ctypes.byref(self._data))
 123         return True
 124
 125     def get_result_data(self):
 126         if not self._data:
 127             return None
 128         return {
 129             'proto_nr': self._data.protocol,
 130             'proto_name': self._data.protocol_name.decode('UTF-8', 'ignore'),
 131             'address': self._data.address,
 132             'command': self._data.command,
 133             'repeat': bool(self._data.flags & self.FLAG_REPETITION),
 134             'release': bool(self._data.flags & self.FLAG_RELEASE),
 135             'start': self._data.start_sample,
 136             'end': self._data.end_sample,
 137         }