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65 lines
2.2 KiB
Python
65 lines
2.2 KiB
Python
# OptimFROG reader/tagger
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#
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# Copyright 2006 Lukas Lalinsky <lalinsky@gmail.com>
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#
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# This program is free software; you can redistribute it and/or modify
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# it under the terms of the GNU General Public License version 2 as
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# published by the Free Software Foundation.
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#
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# $Id: optimfrog.py 3923 2006-10-21 15:07:13Z luks $
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"""OptimFROG audio streams with APEv2 tags.
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OptimFROG is a lossless audio compression program. Its main goal is to
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reduce at maximum the size of audio files, while permitting bit
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identical restoration for all input. It is similar with the ZIP
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compression, but it is highly specialized to compress audio data.
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Only versions 4.5 and higher are supported.
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For more information, see http://www.losslessaudio.org/
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"""
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__all__ = ["OptimFROG", "Open", "delete"]
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import struct
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from lib.mutagen.apev2 import APEv2File, error, delete
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class OptimFROGHeaderError(error): pass
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class OptimFROGInfo(object):
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"""OptimFROG stream information.
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Attributes:
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channels - number of audio channels
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length - file length in seconds, as a float
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sample_rate - audio sampling rate in Hz
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"""
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def __init__(self, fileobj):
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header = fileobj.read(76)
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if (len(header) != 76 or not header.startswith("OFR ") or
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struct.unpack("<I", header[4:8])[0] not in [12, 15]):
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raise OptimFROGHeaderError("not an OptimFROG file")
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(total_samples, total_samples_high, sample_type, self.channels,
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self.sample_rate) = struct.unpack("<IHBBI", header[8:20])
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total_samples += total_samples_high << 32
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self.channels += 1
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if self.sample_rate:
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self.length = float(total_samples) / (self.channels *
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self.sample_rate)
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else:
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self.length = 0.0
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def pprint(self):
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return "OptimFROG, %.2f seconds, %d Hz" % (self.length,
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self.sample_rate)
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class OptimFROG(APEv2File):
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_Info = OptimFROGInfo
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def score(filename, fileobj, header):
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return (header.startswith("OFR") + filename.endswith(".ofr") +
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filename.endswith(".ofs"))
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score = staticmethod(score)
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