def test_is_aligned(self):
r = BitReader(BytesIO(b"\xAB\xCD\xEF"))
self.assertTrue(r.is_aligned())
r.skip(1)
self.assertFalse(r.is_aligned())
r.skip(7)
self.assertTrue(r.is_aligned())
r.bits(7)
self.assertFalse(r.is_aligned())
r.bits(1)
self.assertTrue(r.is_aligned())
def test_is_aligned(self):
r = BitReader(cBytesIO(b"\xAB\xCD\xEF"))
self.assertTrue(r.is_aligned())
r.skip(1)
self.assertFalse(r.is_aligned())
r.skip(7)
self.assertTrue(r.is_aligned())
r.bits(7)
self.assertFalse(r.is_aligned())
r.bits(1)
self.assertTrue(r.is_aligned())
def __init__(self, fileobj, length):
"""Raises DescriptorError"""
r = BitReader(fileobj)
try:
self.ES_ID = r.bits(16)
self.streamDependenceFlag = r.bits(1)
self.URL_Flag = r.bits(1)
self.OCRstreamFlag = r.bits(1)
self.streamPriority = r.bits(5)
if self.streamDependenceFlag:
self.dependsOn_ES_ID = r.bits(16)
if self.URL_Flag:
URLlength = r.bits(8)
self.URLstring = r.bytes(URLlength)
if self.OCRstreamFlag:
self.OCR_ES_Id = r.bits(16)
tag = r.bits(8)
except BitReaderError as e:
raise DescriptorError(e)
if tag != DecoderConfigDescriptor.TAG:
raise DescriptorError("unexpected DecoderConfigDescrTag %d" % tag)
assert r.is_aligned()
self.decConfigDescr = DecoderConfigDescriptor.parse(fileobj)
def __init__(self, fileobj, length):
"""Raises DescriptorError"""
r = BitReader(fileobj)
try:
self.objectTypeIndication = r.bits(8)
self.streamType = r.bits(6)
self.upStream = r.bits(1)
self.reserved = r.bits(1)
self.bufferSizeDB = r.bits(24)
self.maxBitrate = r.bits(32)
self.avgBitrate = r.bits(32)
if (self.objectTypeIndication, self.streamType) != (0x40, 0x5):
return
# all from here is optional
if length * 8 == r.get_position():
return
tag = r.bits(8)
except BitReaderError as e:
raise DescriptorError(e)
if tag == DecoderSpecificInfo.TAG:
assert r.is_aligned()
self.decSpecificInfo = DecoderSpecificInfo.parse(fileobj)
def __init__(self, fileobj, length):
"""Raises DescriptorError"""
r = BitReader(fileobj)
try:
self.objectTypeIndication = r.bits(8)
self.streamType = r.bits(6)
self.upStream = r.bits(1)
self.reserved = r.bits(1)
self.bufferSizeDB = r.bits(24)
self.maxBitrate = r.bits(32)
self.avgBitrate = r.bits(32)
if (self.objectTypeIndication, self.streamType) != (0x40, 0x5):
return
# all from here is optional
if length * 8 == r.get_position():
return
tag = r.bits(8)
except BitReaderError as e:
raise DescriptorError(e)
if tag == DecoderSpecificInfo.TAG:
assert r.is_aligned()
self.decSpecificInfo = DecoderSpecificInfo.parse(fileobj)
def __init__(self, fileobj, length):
"""Raises DescriptorError"""
r = BitReader(fileobj)
try:
self.ES_ID = r.bits(16)
self.streamDependenceFlag = r.bits(1)
self.URL_Flag = r.bits(1)
self.OCRstreamFlag = r.bits(1)
self.streamPriority = r.bits(5)
if self.streamDependenceFlag:
self.dependsOn_ES_ID = r.bits(16)
if self.URL_Flag:
URLlength = r.bits(8)
self.URLstring = r.bytes(URLlength)
if self.OCRstreamFlag:
self.OCR_ES_Id = r.bits(16)
tag = r.bits(8)
except BitReaderError as e:
raise DescriptorError(e)
if tag != DecoderConfigDescriptor.TAG:
raise DescriptorError("unexpected DecoderConfigDescrTag %d" % tag)
assert r.is_aligned()
self.decConfigDescr = DecoderConfigDescriptor.parse(fileobj)
def _parse_esds(self, esds, fileobj):
assert esds.name == b"esds"
ok, data = esds.read(fileobj)
if not ok:
raise ASEntryError("truncated %s atom" % esds.name)
try:
version, flags, data = parse_full_atom(data)
except ValueError as e:
raise ASEntryError(e)
if version != 0:
raise ASEntryError("Unsupported version %d" % version)
fileobj = cBytesIO(data)
r = BitReader(fileobj)
try:
tag = r.bits(8)
if tag != ES_Descriptor.TAG:
raise ASEntryError("unexpected descriptor: %d" % tag)
assert r.is_aligned()
except BitReaderError as e:
raise ASEntryError(e)
try:
decSpecificInfo = ES_Descriptor.parse(fileobj)
except DescriptorError as e:
raise ASEntryError(e)
dec_conf_desc = decSpecificInfo.decConfigDescr
self.bitrate = dec_conf_desc.avgBitrate
self.codec += dec_conf_desc.codec_param
self.codec_description = dec_conf_desc.codec_desc
decSpecificInfo = dec_conf_desc.decSpecificInfo
if decSpecificInfo is not None:
if decSpecificInfo.channels != 0:
self.channels = decSpecificInfo.channels
if decSpecificInfo.sample_rate != 0:
self.sample_rate = decSpecificInfo.sample_rate
def _parse_esds(self, esds, fileobj):
assert esds.name == b"esds"
ok, data = esds.read(fileobj)
if not ok:
raise ASEntryError("truncated %s atom" % esds.name)
try:
version, flags, data = parse_full_atom(data)
except ValueError as e:
raise ASEntryError(e)
if version != 0:
raise ASEntryError("Unsupported version %d" % version)
fileobj = cBytesIO(data)
r = BitReader(fileobj)
try:
tag = r.bits(8)
if tag != ES_Descriptor.TAG:
raise ASEntryError("unexpected descriptor: %d" % tag)
assert r.is_aligned()
except BitReaderError as e:
raise ASEntryError(e)
try:
decSpecificInfo = ES_Descriptor.parse(fileobj)
except DescriptorError as e:
raise ASEntryError(e)
dec_conf_desc = decSpecificInfo.decConfigDescr
self.bitrate = dec_conf_desc.avgBitrate
self.codec += dec_conf_desc.codec_param
self.codec_description = dec_conf_desc.codec_desc
decSpecificInfo = dec_conf_desc.decSpecificInfo
if decSpecificInfo is not None:
if decSpecificInfo.channels != 0:
self.channels = decSpecificInfo.channels
if decSpecificInfo.sample_rate != 0:
self.sample_rate = decSpecificInfo.sample_rate
def __init__(self, atom, fileobj):
ok, data = atom.read(fileobj)
if not ok:
raise ASEntryError("too short %r atom" % atom.name)
fileobj = cBytesIO(data)
r = BitReader(fileobj)
try:
# SampleEntry
r.skip(6 * 8) # reserved
r.skip(2 * 8) # data_ref_index
# AudioSampleEntry
r.skip(8 * 8) # reserved
self.channels = r.bits(16)
self.sample_size = r.bits(16)
r.skip(2 * 8) # pre_defined
r.skip(2 * 8) # reserved
self.sample_rate = r.bits(32) >> 16
except BitReaderError as e:
raise ASEntryError(e)
assert r.is_aligned()
try:
extra = Atom(fileobj)
except AtomError as e:
raise ASEntryError(e)
self.codec = atom.name.decode("latin-1")
self.codec_description = None
if atom.name == b"mp4a" and extra.name == b"esds":
self._parse_esds(extra, fileobj)
elif atom.name == b"alac" and extra.name == b"alac":
self._parse_alac(extra, fileobj)
elif atom.name == b"ac-3" and extra.name == b"dac3":
self._parse_dac3(extra, fileobj)
if self.codec_description is None:
self.codec_description = self.codec.upper()
def __init__(self, atom, fileobj):
ok, data = atom.read(fileobj)
if not ok:
raise ASEntryError("too short %r atom" % atom.name)
fileobj = cBytesIO(data)
r = BitReader(fileobj)
try:
# SampleEntry
r.skip(6 * 8) # reserved
r.skip(2 * 8) # data_ref_index
# AudioSampleEntry
r.skip(8 * 8) # reserved
self.channels = r.bits(16)
self.sample_size = r.bits(16)
r.skip(2 * 8) # pre_defined
r.skip(2 * 8) # reserved
self.sample_rate = r.bits(32) >> 16
except BitReaderError as e:
raise ASEntryError(e)
assert r.is_aligned()
try:
extra = Atom(fileobj)
except AtomError as e:
raise ASEntryError(e)
self.codec = atom.name.decode("latin-1")
self.codec_description = None
if atom.name == b"mp4a" and extra.name == b"esds":
self._parse_esds(extra, fileobj)
elif atom.name == b"alac" and extra.name == b"alac":
self._parse_alac(extra, fileobj)
elif atom.name == b"ac-3" and extra.name == b"dac3":
self._parse_dac3(extra, fileobj)
if self.codec_description is None:
self.codec_description = self.codec.upper()
def __init__(self, xing, fileobj):
"""Raises LAMEError if parsing fails"""
payload = fileobj.read(27)
if len(payload) != 27:
raise LAMEError("Not enough data")
# extended lame header
r = BitReader(cBytesIO(payload))
revision = r.bits(4)
if revision != 0:
raise LAMEError("unsupported header revision %d" % revision)
self.vbr_method = r.bits(4)
self.lowpass_filter = r.bits(8) * 100
# these have a different meaning for lame; expose them again here
self.quality = (100 - xing.vbr_scale) % 10
self.vbr_quality = (100 - xing.vbr_scale) // 10
track_peak_data = r.bytes(4)
if track_peak_data == b"\x00\x00\x00\x00":
self.track_peak = None
else:
# see PutLameVBR() in LAME's VbrTag.c
self.track_peak = (
cdata.uint32_be(track_peak_data) - 0.5) / 2 ** 23
track_gain_type = r.bits(3)
self.track_gain_origin = r.bits(3)
sign = r.bits(1)
gain_adj = r.bits(9) / 10.0
if sign:
gain_adj *= -1
if track_gain_type == 1:
self.track_gain_adjustment = gain_adj
else:
self.track_gain_adjustment = None
assert r.is_aligned()
album_gain_type = r.bits(3)
self.album_gain_origin = r.bits(3)
sign = r.bits(1)
album_gain_adj = r.bits(9) / 10.0
if album_gain_type == 2:
self.album_gain_adjustment = album_gain_adj
else:
self.album_gain_adjustment = None
self.encoding_flags = r.bits(4)
self.ath_type = r.bits(4)
self.bitrate = r.bits(8)
self.encoder_delay_start = r.bits(12)
self.encoder_padding_end = r.bits(12)
self.source_sample_frequency_enum = r.bits(2)
self.unwise_setting_used = r.bits(1)
self.stereo_mode = r.bits(3)
self.noise_shaping = r.bits(2)
sign = r.bits(1)
mp3_gain = r.bits(7)
if sign:
mp3_gain *= -1
self.mp3_gain = mp3_gain
r.skip(2)
self.surround_info = r.bits(3)
self.preset_used = r.bits(11)
self.music_length = r.bits(32)
self.music_crc = r.bits(16)
self.header_crc = r.bits(16)
assert r.is_aligned()
def __init__(self, fileobj):
"""Raises HeaderNotFoundError"""
self.frame_offset = fileobj.tell()
r = BitReader(fileobj)
try:
if r.bits(11) != 0x7ff:
raise HeaderNotFoundError("invalid sync")
version = r.bits(2)
layer = r.bits(2)
protection = r.bits(1)
bitrate = r.bits(4)
sample_rate = r.bits(2)
padding = r.bits(1)
r.skip(1) # private
self.mode = r.bits(2)
r.skip(6)
except BitReaderError:
raise HeaderNotFoundError("truncated header")
assert r.get_position() == 32 and r.is_aligned()
# try to be strict here to redice the chance of a false positive
if version == 1 or layer == 0 or sample_rate == 0x3 or \
bitrate == 0xf or bitrate == 0:
raise HeaderNotFoundError("invalid header")
self.channels = 1 if self.mode == MONO else 2
self.version = [2.5, None, 2, 1][version]
self.layer = 4 - layer
self.protected = not protection
self.padding = bool(padding)
self.bitrate = self.__BITRATE[(self.version, self.layer)][bitrate]
self.bitrate *= 1000
self.sample_rate = self.__RATES[self.version][sample_rate]
if self.layer == 1:
frame_size = 384
slot = 4
elif self.version >= 2 and self.layer == 3:
frame_size = 576
slot = 1
else:
frame_size = 1152
slot = 1
frame_length = (
((frame_size // 8 * self.bitrate) // self.sample_rate) +
padding) * slot
self.sketchy = True
# Try to find/parse the Xing header, which trumps the above length
# and bitrate calculation.
if self.layer == 3:
self._parse_vbr_header(fileobj, self.frame_offset, frame_size,
frame_length)
fileobj.seek(self.frame_offset + frame_length, 0)
