[ctc]fix false rejection result from long time silence. (#149)

* [ctc]fix false rejection result from long time silence.

* fix list index out of range.

---------

Co-authored-by: dujing <dujing@xmov.ai>

wekws/bin/stream_kws_ctc.py

@@ -481,6 +481,15 @@ class KeyWordSpotter(torch.nn.Module):
 
         # update frame offset
         self.total_frames += len(probs) * self.downsampling
+
+        # For streaming kws, the cur_hyps should be reset if the time of
+        # a possible keyword last over the max_frames value you set.
+        # see this issue:https://github.com/duj12/kws_demo/issues/2
+        if len(self.cur_hyps) > 0 and len(self.cur_hyps[0][0]) > 0:
+            keyword_may_start = int(self.cur_hyps[0][1][2][0]['frame'])
+            if (self.total_frames - keyword_may_start) > self.max_frames:
+                self.reset()
+
         return self.result
 
     def reset(self):

wekws/bin/train.py

@@ -141,14 +141,13 @@ def main():
         configs['model']['cmvn'] = {}
         configs['model']['cmvn']['norm_var'] = args.norm_var
         configs['model']['cmvn']['cmvn_file'] = args.cmvn_file
+    # Init asr model from configs
+    model = init_model(configs['model'])
     if rank == 0:
         saved_config_path = os.path.join(args.model_dir, 'config.yaml')
         with open(saved_config_path, 'w') as fout:
             data = yaml.dump(configs)
             fout.write(data)
-
-    # Init asr model from configs
-    model = init_model(configs['model'])
         print(model)
     num_params = count_parameters(model)
     print('the number of model params: {}'.format(num_params))