ir_sirc: symbolic names for IR pulse widths, more line trimming

Concentrate the magic numbers for IR pulse widths at the top of the
source file. Drop more unused variables. Rename others to shorten more
text lines.

1 files changed, 17 insertions, 11 deletions

diff --git a/decoders/ir_sirc/pd.py b/decoders/ir_sirc/pd.py
index 8c9c5fb..0afacb0 100644
--- a/decoders/ir_sirc/pd.py
+++ b/decoders/ir_sirc/pd.py
@@ -33,6 +33,11 @@ class SIRCErrorSilent(SIRCError):
 class Ann:
     BIT, AGC, PAUSE, START, CMD, ADDR, EXT, REMOTE, WARN = range(9)
 
+AGC_USEC = 2400
+ONE_USEC = 1200
+ZERO_USEC = 600
+PAUSE_USEC = 600
+
 class Decoder(srd.Decoder):
     api_version = 3
     id = 'ir_sirc'
@@ -114,17 +119,17 @@ class Decoder(srd.Decoder):
         _, high_ss, high_es, (edge, timeout) = self.wait_wrap([{0: e}], 2000)
         if timeout:
             raise SIRCError('Bit High Timeout')
-        if self.tolerance(high_ss, high_es, 1200):
+        if self.tolerance(high_ss, high_es, ONE_USEC):
             bit = 1
-        elif self.tolerance(high_ss, high_es, 600):
+        elif self.tolerance(high_ss, high_es, ZERO_USEC):
             bit = 0
         else:
             raise SIRCError('Bit Low Timeout')
         try:
-            _, low_ss, low_es, matched = self.read_pulse(not self.active, 600)
+            _, low_ss, low_es, _ = self.read_pulse(not self.active, PAUSE_USEC)
             good = True
         except SIRCError:
-            low_es = high_es + int(600 * self.snum_per_us)
+            low_es = high_es + int(PAUSE_USEC * self.snum_per_us)
             good = False
         self.putg(high_ss, low_es, Ann.BIT, ['{}'.format(bit)])
         return bit, high_ss, low_es, good
@@ -132,8 +137,8 @@ class Decoder(srd.Decoder):
     def read_signal(self):
         # Start code
         try:
-            _, agc_ss, agc_es, matched = self.read_pulse(self.active, 2400)
-            _, pause_ss, pause_es, matched = self.read_pulse(not self.active, 600)
+            _, agc_ss, agc_es, _ = self.read_pulse(self.active, AGC_USEC)
+            _, pause_ss, pause_es, _ = self.read_pulse(not self.active, PAUSE_USEC)
         except SIRCError:
             raise SIRCErrorSilent('not an SIRC message')
         self.putg(agc_ss, agc_es, Ann.AGC, ['AGC', 'A'])
@@ -161,7 +166,7 @@ class Decoder(srd.Decoder):
                     address = bits[7:12]
                     extended = bits[12:20]
                 else:
-                    raise SIRCError('incorrect number of bits: {}'.format(len(bits)))
+                    raise SIRCError('incorrect bits count {}'.format(len(bits)))
                 break
 
         command_num = bitpack([b[0] for b in command])
@@ -190,13 +195,14 @@ class Decoder(srd.Decoder):
         if not self.samplerate:
             raise SamplerateError('Cannot decode without samplerate.')
 
+        unknown = (['Unknown Device: ', 'UNK: '], {})
         while True:
             e = 'h' if self.active else 'l'
-            signal, ss, es, matched = self.wait_wrap([{0: e}], None)
+            _, ss, es, _ = self.wait_wrap([{0: e}], None)
             try:
-                address, command, extended, payload_ss, payload_es = self.read_signal()
-                names, commands = ADDRESSES.get((address, extended), (['Unknown Device: ', 'UNK: '], {}))
-                text = commands.get(command, 'Unknown')
+                addr, cmd, ext, payload_ss, payload_es = self.read_signal()
+                names, cmds = ADDRESSES.get((addr, ext), unknown)
+                text = cmds.get(cmd, 'Unknown')
                 self.putg(es, payload_es, Ann.REMOTE, [n + text for n in names])
             except SIRCErrorSilent as e:
                 continue