[demo] support English

app.py

@@ -20,7 +20,8 @@ import wenetruntime as wenet
 import librosa
 
 wenet.set_log_level(2)
-decoder = wenet.Decoder(lang='chs')
+chs_decoder = wenet.Decoder(lang='chs')
+en_decoder = wenet.Decoder(lang='en')
 
 
 def recognition(audio, lang='CN'):
@@ -30,9 +31,9 @@ def recognition(audio, lang='CN'):
     # NOTE: model supports 16k sample_rate
     y = (y * (1 << 15)).astype("int16")
     if lang == 'CN':
-        ans = decoder.decode(y.tobytes(), True)
+        ans = chs_decoder.decode(y.tobytes(), True)
     elif lang == 'EN':
-        return "ERROR! English is not supported yet!"
+        ans = en_decoder.decode(y.tobytes(), True)
     else:
         return "ERROR! Please select a language!"