49 lines
1.6 KiB
Python
Executable File
49 lines
1.6 KiB
Python
Executable File
#!/usr/bin/python
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import sys, string, math, argparse
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parser = argparse.ArgumentParser()
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parser.add_argument('-l', '--length', type=int, default=64, help="length of note table")
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parser.add_argument('-u', '--upper', type=int, default=49, help="upper note # to test")
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parser.add_argument('-f', '--freq', type=float, default=3579545/32.0, help="base frequency (Hz)")
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parser.add_argument('-b', '--bias', type=float, default=0, help="divisor bias")
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parser.add_argument('-m', '--maxbits', type=float, default=12, help="max. # of bits")
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args = parser.parse_args()
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test_notes = args.upper
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final_notes = args.length
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basehz = args.freq
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bias = args.bias
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maxval = (1<<int(args.maxbits))-1
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results = []
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for a440 in range(4300,4500):
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error = 0
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for note in range(1,test_notes):
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notehz = a440 / 10.0 * math.pow(2.0, (note - 49) / 12.0);
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period = int(round(basehz / notehz))
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while period > maxval:
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period /= 2
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tonehz = basehz / period
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error += abs(notehz-tonehz)
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#print a440,note,notehz,notehz-tonehz,period
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#if a440 == 4405:
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# print '%d,%f,%d' % (note,tonehz-notehz,period)
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results.append((error, a440))
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results.sort()
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best_error, best_a440 = results[0]
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best_a440 /= 10.0
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print '//', args
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print '//', best_a440, best_error, test_notes
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print "const int note_table[%d] = {" % final_notes
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for note in range(0,final_notes):
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notehz = best_a440 * math.pow(2.0, (note - 49) / 12.0);
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period = int(round(basehz / notehz)) - bias
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while period > maxval:
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period /= 2
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print '%d,' % period,
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print "};"
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