def __init__(self, fileobj):
"""Raises MusepackHeaderError"""
header = fileobj.read(4)
if len(header) != 4:
raise MusepackHeaderError("not a Musepack file")
# Skip ID3v2 tags
if header[:3] == b"ID3":
header = fileobj.read(6)
if len(header) != 6:
raise MusepackHeaderError("not a Musepack file")
size = 10 + BitPaddedInt(header[2:6])
fileobj.seek(size)
header = fileobj.read(4)
if len(header) != 4:
raise MusepackHeaderError("not a Musepack file")
if header.startswith(b"MPCK"):
self.__parse_sv8(fileobj)
else:
self.__parse_sv467(fileobj)
if not self.bitrate and self.length != 0:
fileobj.seek(0, 2)
self.bitrate = intround(fileobj.tell() * 8 / self.length)
def __init__(self, fileobj):
"""Raises MusepackHeaderError"""
header = fileobj.read(4)
if len(header) != 4:
raise MusepackHeaderError("not a Musepack file")
# Skip ID3v2 tags
if header[:3] == b"ID3":
header = fileobj.read(6)
if len(header) != 6:
raise MusepackHeaderError("not a Musepack file")
size = 10 + BitPaddedInt(header[2:6])
fileobj.seek(size)
header = fileobj.read(4)
if len(header) != 4:
raise MusepackHeaderError("not a Musepack file")
if header.startswith(b"MPCK"):
self.__parse_sv8(fileobj)
else:
self.__parse_sv467(fileobj)
if not self.bitrate and self.length != 0:
fileobj.seek(0, 2)
self.bitrate = intround(fileobj.tell() * 8 / self.length)
def _parse_vbr_header(self, fileobj, frame_offset, frame_size,
frame_length):
"""Does not raise"""
# Xing
xing_offset = XingHeader.get_offset(self)
fileobj.seek(frame_offset + xing_offset, 0)
try:
xing = XingHeader(fileobj)
except XingHeaderError:
pass
else:
lame = xing.lame_header
self.sketchy = False
self.bitrate_mode = _guess_xing_bitrate_mode(xing)
self.encoder_settings = xing.get_encoder_settings()
if xing.frames != -1:
samples = frame_size * xing.frames
if xing.bytes != -1 and samples > 0:
# the first frame is only included in xing.bytes but
# not in xing.frames, skip it.
audio_bytes = max(0, xing.bytes - frame_length)
self.bitrate = intround((
audio_bytes * 8 * self.sample_rate) / float(samples))
if lame is not None:
samples -= lame.encoder_delay_start
samples -= lame.encoder_padding_end
if samples < 0:
# older lame versions wrote bogus delay/padding for short
# files with low bitrate
samples = 0
self.length = float(samples) / self.sample_rate
if xing.lame_version_desc:
self.encoder_info = u"LAME %s" % xing.lame_version_desc
if lame is not None:
self.track_gain = lame.track_gain_adjustment
self.track_peak = lame.track_peak
self.album_gain = lame.album_gain_adjustment
return
# VBRI
vbri_offset = VBRIHeader.get_offset(self)
fileobj.seek(frame_offset + vbri_offset, 0)
try:
vbri = VBRIHeader(fileobj)
except VBRIHeaderError:
pass
else:
self.bitrate_mode = BitrateMode.VBR
self.encoder_info = u"FhG"
self.sketchy = False
self.length = float(frame_size * vbri.frames) / self.sample_rate
if self.length:
self.bitrate = int((vbri.bytes * 8) / self.length)
def test_intround():
assert intround(2.5) == 2
assert intround(2.6) == 3
assert intround(2.4) == 2
def test_intround():
assert intround(2.5) == 2
assert intround(2.6) == 3
assert intround(2.4) == 2
