Allowing PFB interpolator to be called without specifying the taps; autogen taps inside hierblock.

1 files changed, 19 insertions, 2 deletions

diff --git a/gnuradio-core/src/python/gnuradio/blks2impl/pfb_interpolator.py b/gnuradio-core/src/python/gnuradio/blks2impl/pfb_interpolator.py
index db2944042..a210e3de8 100644
--- a/gnuradio-core/src/python/gnuradio/blks2impl/pfb_interpolator.py
+++ b/gnuradio-core/src/python/gnuradio/blks2impl/pfb_interpolator.py
@@ -20,7 +20,7 @@
 # Boston, MA 02110-1301, USA.
 # 
 
-from gnuradio import gr
+from gnuradio import gr, optfir
 
 class pfb_interpolator_ccf(gr.hier_block2):
     '''
@@ -31,7 +31,7 @@ class pfb_interpolator_ccf(gr.hier_block2):
     streams. This block is provided to be consistent with the interface to the
     other PFB block.
     '''
-    def __init__(self, interp, taps):
+    def __init__(self, interp, taps=None, atten=100):
 	gr.hier_block2.__init__(self, "pfb_interpolator_ccf",
 				gr.io_signature(1, 1, gr.sizeof_gr_complex), # Input signature
 				gr.io_signature(1, 1, gr.sizeof_gr_complex)) # Output signature
@@ -39,6 +39,23 @@ class pfb_interpolator_ccf(gr.hier_block2):
         self._interp = interp
         self._taps = taps
 
+        if taps is not None:
+            self._taps = taps
+        else:
+            # Create a filter that covers the full bandwidth of the input signal
+            bw = 0.4
+            tb = 0.2
+            ripple = 0.1
+            made = False
+            while not made:
+                try:
+                    self._taps = optfir.low_pass(self._interp, self._interp, bw, bw+tb, ripple, atten)
+                    made = True
+                except RuntimeError:
+                    ripple += 0.01
+                    made = False
+                    print("Warning: set ripple to %.4f dB. If this is a problem, adjust the attenuation or create your own filter taps." % (ripple))
+
         self.pfb = gr.pfb_interpolator_ccf(self._interp, self._taps)
 
         self.connect(self, self.pfb)