From: Tom Rondeau <trondeau@vt.edu>
Date: Tue, 28 Dec 2010 17:47:32 +0000 (-0500)
Subject: Updating the arb. resampler to use the optfir filter that provides better specificati... 
X-Git-Url: https://git.gag.com/?a=commitdiff_plain;h=ae03fd9ae853055548be3e2c0ff5754828142c2a;p=debian%2Fgnuradio

Updating the arb. resampler to use the optfir filter that provides better specificatiion of stopband atten.
---

diff --git a/gnuradio-core/src/python/gnuradio/blks2impl/pfb_arb_resampler.py b/gnuradio-core/src/python/gnuradio/blks2impl/pfb_arb_resampler.py
index cd9289fa..c4e496c4 100644
--- a/gnuradio-core/src/python/gnuradio/blks2impl/pfb_arb_resampler.py
+++ b/gnuradio-core/src/python/gnuradio/blks2impl/pfb_arb_resampler.py
@@ -20,7 +20,7 @@
 # Boston, MA 02110-1301, USA.
 # 
 
-from gnuradio import gr
+from gnuradio import gr, optfir
 
 class pfb_arb_resampler_ccf(gr.hier_block2):
     '''
@@ -31,7 +31,7 @@ class pfb_arb_resampler_ccf(gr.hier_block2):
     streams. This block is provided to be consistent with the interface to the
     other PFB block.
     '''
-    def __init__(self, rate, taps=None, flt_size=32, atten=80):
+    def __init__(self, rate, taps=None, flt_size=32, atten=100):
 	gr.hier_block2.__init__(self, "pfb_arb_resampler_ccf",
 				gr.io_signature(1, 1, gr.sizeof_gr_complex), # Input signature
 				gr.io_signature(1, 1, gr.sizeof_gr_complex)) # Output signature
@@ -43,9 +43,19 @@ class pfb_arb_resampler_ccf(gr.hier_block2):
             self._taps = taps
         else:
             # Create a filter that covers the full bandwidth of the input signal
-            bw = 0.5
-            tb = 0.1
-            self._taps = gr.firdes.low_pass_2(self._size, self._size, bw, tb, atten)
+            bw = 0.4
+            tb = 0.2
+            ripple = 0.1
+            #self._taps = gr.firdes.low_pass_2(self._size, self._size, bw, tb, atten)
+            made = False
+            while not made:
+                try:
+                    self._taps = optfir.low_pass(self._size, self._size, 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_arb_resampler_ccf(self._rate, self._taps, self._size)