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https://github.com/a2-4am/passport.py.git
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64 lines
2.6 KiB
Python
Executable File
64 lines
2.6 KiB
Python
Executable File
from passport.wozardry import Track, raise_if
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from passport import a2rchery
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import bitarray
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import collections
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class A2RSeekError(a2rchery.A2RError): pass
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class A2RImage:
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def __init__(self, filename=None, stream=None):
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self.filename = filename
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self.tracks = collections.OrderedDict()
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self.a2r_image = a2rchery.A2RReader(filename, stream)
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def to_bits(self, flux_record):
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"""|flux_record| is a dictionary of 'capture_type', 'data_length', 'tick_count', and 'data'"""
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bits = bitarray.bitarray()
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estimated_track_length = 0
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if not flux_record or flux_record["capture_type"] != a2rchery.kCaptureTiming:
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return bits, estimated_track_length, 0
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ticks = 0
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flux_total = 0
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fluxxen = flux_record["data"]
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speeds = [(len([1 for i in fluxxen if i%t==0]), t) for t in range(0x1c,0x25)]
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speeds.sort()
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speed = speeds[-1][1]
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for flux_value in fluxxen[1:]:
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ticks += flux_value
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if not estimated_track_length and ticks > flux_record["tick_count"]:
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estimated_track_length = len(bits)
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flux_total += flux_value
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if flux_value == 0xFF:
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continue
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bits.extend([0] * ((flux_total - speed//2) // speed))
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bits.append(1)
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flux_total = 0
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return bits, estimated_track_length, speed
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def seek(self, track_num):
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if type(track_num) != float:
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track_num = float(track_num)
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if track_num < 0.0 or \
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track_num > 35.0 or \
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track_num.as_integer_ratio()[1] not in (1,2,4):
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raise A2RSeekError("Invalid track %s" % track_num)
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location = int(track_num * 4)
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if not self.tracks.get(location):
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# just return the bits from the first flux read
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# (if the caller determines that they're not good, it will call reseek()
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# which is smarter but takes longer)
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bits = bitarray.bitarray()
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for flux_record in self.a2r_image.flux.get(location, [{}])[:1]:
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bits, track_length, speed = self.to_bits(flux_record)
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self.tracks[location] = Track(bits, len(bits))
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return self.tracks[location]
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def reseek(self, track_num):
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location = int(track_num * 4)
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all_bits = bitarray.bitarray()
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for flux_record in self.a2r_image.flux.get(location, [{}]):
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bits, track_length, speed = self.to_bits(flux_record)
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all_bits.extend(bits)
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self.tracks[location] = Track(all_bits, len(all_bits))
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return self.tracks[location]
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