X-Git-Url: https://sigrok.org/gitweb/?p=libsigrokdecode.git;a=blobdiff_plain;f=decoders%2Fusb_signalling%2Fpd.py;h=8a323e0c37af1cc8d7c63c04e727472607e2c7fa;hp=d2a1e8add21a7fd0ff9f7b0b0fc254065db579cd;hb=f372d597739a30e0106aebc8225c1edebf6d93e3;hpb=ed41649709abc02362df526cbd725775000e8199

diff --git a/decoders/usb_signalling/pd.py b/decoders/usb_signalling/pd.py
index d2a1e8a..8a323e0 100644
--- a/decoders/usb_signalling/pd.py
+++ b/decoders/usb_signalling/pd.py
@@ -94,6 +94,7 @@ class Decoder(srd.Decoder):
     ]
 
     def __init__(self):
+        self.samplerate = None
         self.oldsym = 'J' # The "idle" state is J.
         self.ss_sop = None
         self.ss_block = None
@@ -107,12 +108,16 @@ class Decoder(srd.Decoder):
         self.consecutive_ones = 0
         self.state = 'IDLE'
 
-    def start(self, metadata):
+    def start(self):
         self.out_proto = self.add(srd.OUTPUT_PROTO, 'usb_signalling')
         self.out_ann = self.add(srd.OUTPUT_ANN, 'usb_signalling')
-        self.bitrate = bitrates[self.options['signalling']]
-        self.bitwidth = float(metadata['samplerate']) / float(self.bitrate)
-        self.halfbit = int(self.bitwidth / 2)
+
+    def metadata(self, key, value):
+        if key == srd.SRD_CONF_SAMPLERATE:
+            self.samplerate = value
+            self.bitrate = bitrates[self.options['signalling']]
+            self.bitwidth = float(self.samplerate) / float(self.bitrate)
+            self.halfbit = int(self.bitwidth / 2)
 
     def report(self):
         pass
@@ -201,6 +206,8 @@ class Decoder(srd.Decoder):
         self.oldsym = sym
 
     def decode(self, ss, es, data):
+        if self.samplerate is None:
+            raise Exception("Cannot decode without samplerate.")
         for (self.samplenum, pins) in data:
             # State machine.
             if self.state == 'IDLE':