codec 2 model record I/O test working OK

codec2_model.py

@@ -0,0 +1,79 @@
+#!/usr/bin/python3
+# codec2_model.py
+# David Rowe Dec 2019
+#
+# Python Codec 2 model records I/O
+
+import sys
+import construct
+import numpy as np
+import matplotlib.pyplot as plt
+
+max_amp = 160
+Fs      = 8000
+width   = 256
+
+codec2_model = construct.Struct(
+    "Wo" / construct.Float32l,
+    "L" / construct.Int32sl,
+    "A" / construct.Array(max_amp+1, construct.Float32l),
+    "phi" / construct.Array(max_amp+1, construct.Float32l),
+    "voiced" / construct.Int32sl
+    )
+
+def read(filename):
+    
+    # Determine number of records in file, not very Pythonic I know :-)
+
+    nb_samples = 0
+    with open('/home/david/codec2/build_linux/hts1a.model', 'rb') as f:
+        while True:
+            try:
+                model = codec2_model.parse_stream(f)
+                nb_samples += 1
+            except:
+                f.close()
+                break
+            
+    Wo = np.zeros(nb_samples)
+    L = np.zeros(nb_samples, dtype=int)
+    A = np.zeros((nb_samples, width))
+    phi = np.zeros((nb_samples, width))
+    voiced = np.zeros(nb_samples, dtype=int)
+
+    # Read Codec 2 model records into numpy arrays for further work
+    
+    with open('/home/david/codec2/build_linux/hts1a.model', 'rb') as f:
+        for i in range(nb_samples):
+            model = codec2_model.parse_stream(f)
+            Wo[i] = model.Wo
+            L[i] = model.L
+            A[i,1:L[i]+1] = model.A[1:L[i]+1]
+            phi[i,1:L[i]+1] = model.phi[1:L[i]+1]
+            voiced[i] = model.voiced
+    f.close()
+
+    return Wo, L, A, phi, voiced
+
+def write(Wo, L, A, phi, voiced, filename):
+    nb_samples = Wo.size
+    with open(filename, 'wb') as f:
+        for i in range(nb_samples):
+            model = codec2_model.build(dict(Wo=Wo[i], L=L[i], A=A[i,:max_amp+1], phi=phi[i,:max_amp+1], voiced=voiced[i]))
+            f.write(model)
+            
+if __name__ == "__main__":
+    # do this first:
+    #   /codec2/build_linux$ ./src/c2sim ../raw/hts1a.raw --modelout hts1a.model
+
+    Wo, L, A, phi, voiced = read("/home/david/codec2/build_linux/hts1a.model")
+    write(Wo, L, A, phi, voiced, "/home/david/codec2/build_linux/hts1a_out.model")
+    
+    plt.figure(1)
+    plt.plot(Wo*4000/np.pi)
+    plt.show(block=False)
+    
+    plt.figure(2)
+    plt.plot(A[30,:])
+    plt.show()
+