diff --git a/test/decoder.py b/test/decoder.py
index f6a131e..378871c 100755
--- a/test/decoder.py
+++ b/test/decoder.py
@@ -170,9 +170,6 @@ if __name__ == "__main__":
         if len(data) != 2:
             break
 
-        if nframes >= 1000:
-            break
-
         (frame_nbytes,) = struct.unpack('=H', data)
 
         print('Decoding frame %d' % nframes, end='\r')
diff --git a/test/encoder.py b/test/encoder.py
index 59490e5..6395524 100755
--- a/test/encoder.py
+++ b/test/encoder.py
@@ -159,6 +159,8 @@ if __name__ == "__main__":
     (sr_hz, pcm) = wavfile.read(args.wav_file.name)
     if sr_hz not in (8000, 16000, 24000, 320000, 48000):
         raise ValueError('Unsupported input samplerate: %d' % sr_hz)
+    if pcm.ndim != 1:
+        raise ValueError('Only single channel wav file supported')
 
     ### Setup ###
 
diff --git a/test/spec.py b/test/spec.py
index 7bce317..c36c242 100644
--- a/test/spec.py
+++ b/test/spec.py
@@ -312,6 +312,7 @@ class SpectrumAnalysis(SpectrumQuantization):
 
         b.write_uint((self.lastnz >> 1) - 1, nbits_lastnz)
         b.write_uint(self.lsb_mode, 1)
+        b.write_uint(self.g_idx, 8)
 
     def encode(self, bits):