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.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, 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 test_bytes_unaligned(self):
r = BitReader(cBytesIO(b"\xAB\xCD\xEF"))
r.skip(4)
self.assertEqual(r.bytes(2), b"\xBC\xDE")
def test_bytes(self):
r = BitReader(cBytesIO(b"\xAB\xCD\xEF"))
self.assertEqual(r.bytes(2), b"\xAB\xCD")
self.assertEqual(r.bytes(0), b"")
def test_bytes_unaligned(self):
r = BitReader(BytesIO(b"\xAB\xCD\xEF"))
r.skip(4)
self.assertEqual(r.bytes(2), b"\xBC\xDE")
def test_bytes(self):
r = BitReader(BytesIO(b"\xAB\xCD\xEF"))
self.assertEqual(r.bytes(2), b"\xAB\xCD")
self.assertEqual(r.bytes(0), b"")
