def _parse_adif(self, fileobj):
r = BitReader(fileobj)
try:
copyright_id_present = r.bits(1)
if copyright_id_present:
r.skip(72) # copyright_id
r.skip(1 + 1) # original_copy, home
bitstream_type = r.bits(1)
self.bitrate = r.bits(23)
npce = r.bits(4)
if bitstream_type == 0:
r.skip(20) # adif_buffer_fullness
pce = ProgramConfigElement(r)
try:
self.sample_rate = _FREQS[pce.sampling_frequency_index]
except IndexError:
pass
self.channels = pce.channels
# other pces..
for i in xrange(npce):
ProgramConfigElement(r)
r.align()
except BitReaderError as e:
raise AACError(e)
# use bitrate + data size to guess length
start = fileobj.tell()
fileobj.seek(0, 2)
length = fileobj.tell() - start
if self.bitrate != 0:
self.length = (8.0 * length) / self.bitrate
def _parse_adif(self, fileobj):
r = BitReader(fileobj)
try:
copyright_id_present = r.bits(1)
if copyright_id_present:
r.skip(72) # copyright_id
r.skip(1 + 1) # original_copy, home
bitstream_type = r.bits(1)
self.bitrate = r.bits(23)
npce = r.bits(4)
if bitstream_type == 0:
r.skip(20) # adif_buffer_fullness
pce = ProgramConfigElement(r)
try:
self.sample_rate = _FREQS[pce.sampling_frequency_index]
except IndexError:
pass
self.channels = pce.channels
# other pces..
for i in xrange(npce):
ProgramConfigElement(r)
r.align()
except BitReaderError as e:
raise AACError(e)
# use bitrate + data size to guess length
start = fileobj.tell()
fileobj.seek(0, 2)
length = fileobj.tell() - start
if self.bitrate != 0:
self.length = (8.0 * length) / self.bitrate
def _parse_adts(self, fileobj, start_offset):
max_initial_read = 512
max_resync_read = 10
max_sync_tries = 10
frames_max = 100
frames_needed = 3
# Try up to X times to find a sync word and read up to Y frames.
# If more than Z frames are valid we assume a valid stream
offset = start_offset
for i in xrange(max_sync_tries):
fileobj.seek(offset)
s = _ADTSStream.find_stream(fileobj, max_initial_read)
if s is None:
raise AACError("sync not found")
# start right after the last found offset
offset += s.offset + 1
for i in xrange(frames_max):
if not s.parse_frame():
break
if not s.sync(max_resync_read):
break
if s.parsed_frames >= frames_needed:
break
else:
raise AACError("no valid stream found (only %d frames)" %
s.parsed_frames)
self.sample_rate = s.frequency
self.channels = s.channels
self.bitrate = s.bitrate
# size from stream start to end of file
fileobj.seek(0, 2)
stream_size = fileobj.tell() - (offset + s.offset)
# approx
self.length = float(s.samples * stream_size) / (s.size * s.frequency)
def _parse_adts(self, fileobj, start_offset):
max_initial_read = 512
max_resync_read = 10
max_sync_tries = 10
frames_max = 100
frames_needed = 3
# Try up to X times to find a sync word and read up to Y frames.
# If more than Z frames are valid we assume a valid stream
offset = start_offset
for i in xrange(max_sync_tries):
fileobj.seek(offset)
s = _ADTSStream.find_stream(fileobj, max_initial_read)
if s is None:
raise AACError("sync not found")
# start right after the last found offset
offset += s.offset + 1
for i in xrange(frames_max):
if not s.parse_frame():
break
if not s.sync(max_resync_read):
break
if s.parsed_frames >= frames_needed:
break
else:
raise AACError(
"no valid stream found (only %d frames)" % s.parsed_frames)
self.sample_rate = s.frequency
self.channels = s.channels
self.bitrate = s.bitrate
# size from stream start to end of file
fileobj.seek(0, 2)
stream_size = fileobj.tell() - (offset + s.offset)
# approx
self.length = float(s.samples * stream_size) / (s.size * s.frequency)
def _key_sort(item):
(key, v) = item
# iTunes always writes the tags in order of "relevance", try
# to copy it as closely as possible.
order = ["\xa9nam", "\xa9ART", "\xa9wrt", "\xa9alb",
"\xa9gen", "gnre", "trkn", "disk",
"\xa9day", "cpil", "pgap", "pcst", "tmpo",
"\xa9too", "----", "covr", "\xa9lyr"]
order = dict(izip(order, xrange(len(order))))
last = len(order)
# If there's no key-based way to distinguish, order by length.
# If there's still no way, go by string comparison on the
# values, so we at least have something determinstic.
return (order.get(key[:4], last), len(repr(v)), repr(v))
def parse_full(cls, asf, fileobj):
"""Raises ASFHeaderError"""
header = cls()
size, num_objects = cls.parse_size(fileobj)
for i in xrange(num_objects):
guid, size = struct.unpack("<16sQ", fileobj.read(24))
obj = BaseObject._get_object(guid)
data = fileobj.read(size - 24)
obj.parse(asf, data)
header.objects.append(obj)
return header
def parse_full(cls, asf, fileobj):
"""Raises ASFHeaderError"""
header = cls()
size, num_objects = cls.parse_size(fileobj)
for i in xrange(num_objects):
guid, size = struct.unpack("<16sQ", fileobj.read(24))
obj = BaseObject._get_object(guid)
data = fileobj.read(size - 24)
obj.parse(asf, data)
header.objects.append(obj)
return header
def _key_sort(item):
(key, v) = item
# iTunes always writes the tags in order of "relevance", try
# to copy it as closely as possible.
order = [
"\xa9nam", "\xa9ART", "\xa9wrt", "\xa9alb", "\xa9gen", "gnre",
"trkn", "disk", "\xa9day", "cpil", "pgap", "pcst", "tmpo",
"\xa9too", "----", "covr", "\xa9lyr"
]
order = dict(izip(order, xrange(len(order))))
last = len(order)
# If there's no key-based way to distinguish, order by length.
# If there's still no way, go by string comparison on the
# values, so we at least have something determinstic.
return (order.get(key[:4], last), len(repr(v)), repr(v))
def parse(self, asf, data):
super(ExtendedContentDescriptionObject, self).parse(asf, data)
num_attributes, = struct.unpack("<H", data[0:2])
pos = 2
for i in xrange(num_attributes):
name_length, = struct.unpack("<H", data[pos:pos + 2])
pos += 2
name = data[pos:pos + name_length]
name = name.decode("utf-16-le").strip("\x00")
pos += name_length
value_type, value_length = struct.unpack("<HH", data[pos:pos + 4])
pos += 4
value = data[pos:pos + value_length]
pos += value_length
attr = ASFBaseAttribute._get_type(value_type)(data=value)
asf._tags.setdefault(self.GUID, []).append((name, attr))
def parse(self, asf, data):
super(ExtendedContentDescriptionObject, self).parse(asf, data)
num_attributes, = struct.unpack("<H", data[0:2])
pos = 2
for i in xrange(num_attributes):
name_length, = struct.unpack("<H", data[pos:pos + 2])
pos += 2
name = data[pos:pos + name_length]
name = name.decode("utf-16-le").strip("\x00")
pos += name_length
value_type, value_length = struct.unpack("<HH", data[pos:pos + 4])
pos += 4
value = data[pos:pos + value_length]
pos += value_length
attr = ASFBaseAttribute._get_type(value_type)(data=value)
asf._tags.setdefault(self.GUID, []).append((name, attr))
def _parse_desc_length_file(cls, fileobj):
"""May raise ValueError"""
value = 0
for i in xrange(4):
try:
b = cdata.uint8(fileobj.read(1))
except cdata.error as e:
raise ValueError(e)
value = (value << 7) | (b & 0x7f)
if not b >> 7:
break
else:
raise ValueError("invalid descriptor length")
return value
def _parse_desc_length_file(cls, fileobj):
"""May raise ValueError"""
value = 0
for i in xrange(4):
try:
b = cdata.uint8(fileobj.read(1))
except cdata.error as e:
raise ValueError(e)
value = (value << 7) | (b & 0x7f)
if not b >> 7:
break
else:
raise ValueError("invalid descriptor length")
return value
def parse(self, asf, data):
super(MetadataLibraryObject, self).parse(asf, data)
num_attributes, = struct.unpack("<H", data[0:2])
pos = 2
for i in xrange(num_attributes):
(language, stream, name_length, value_type,
value_length) = struct.unpack("<HHHHI", data[pos:pos + 12])
pos += 12
name = data[pos:pos + name_length]
name = name.decode("utf-16-le").strip("\x00")
pos += name_length
value = data[pos:pos + value_length]
pos += value_length
args = {'data': value, 'language': language, 'stream': stream}
if value_type == 2:
args['dword'] = False
attr = ASFBaseAttribute._get_type(value_type)(**args)
asf._tags.setdefault(self.GUID, []).append((name, attr))
def parse(self, asf, data):
super(MetadataLibraryObject, self).parse(asf, data)
num_attributes, = struct.unpack("<H", data[0:2])
pos = 2
for i in xrange(num_attributes):
(language, stream, name_length, value_type,
value_length) = struct.unpack("<HHHHI", data[pos:pos + 12])
pos += 12
name = data[pos:pos + name_length]
name = name.decode("utf-16-le").strip("\x00")
pos += name_length
value = data[pos:pos + value_length]
pos += value_length
args = {'data': value, 'language': language, 'stream': stream}
if value_type == 2:
args['dword'] = False
attr = ASFBaseAttribute._get_type(value_type)(**args)
asf._tags.setdefault(self.GUID, []).append((name, attr))
def __init__(self, r):
"""Reads the program_config_element()
Raises BitReaderError
"""
self.element_instance_tag = r.bits(4)
self.object_type = r.bits(2)
self.sampling_frequency_index = r.bits(4)
num_front_channel_elements = r.bits(4)
num_side_channel_elements = r.bits(4)
num_back_channel_elements = r.bits(4)
num_lfe_channel_elements = r.bits(2)
num_assoc_data_elements = r.bits(3)
num_valid_cc_elements = r.bits(4)
mono_mixdown_present = r.bits(1)
if mono_mixdown_present == 1:
r.skip(4)
stereo_mixdown_present = r.bits(1)
if stereo_mixdown_present == 1:
r.skip(4)
matrix_mixdown_idx_present = r.bits(1)
if matrix_mixdown_idx_present == 1:
r.skip(3)
elms = num_front_channel_elements + num_side_channel_elements + \
num_back_channel_elements
channels = 0
for i in xrange(elms):
channels += 1
element_is_cpe = r.bits(1)
if element_is_cpe:
channels += 1
r.skip(4)
channels += num_lfe_channel_elements
self.channels = channels
r.skip(4 * num_lfe_channel_elements)
r.skip(4 * num_assoc_data_elements)
r.skip(5 * num_valid_cc_elements)
r.align()
comment_field_bytes = r.bits(8)
r.skip(8 * comment_field_bytes)
def __init__(self, r):
"""Reads the program_config_element()
Raises BitReaderError
"""
self.element_instance_tag = r.bits(4)
self.object_type = r.bits(2)
self.sampling_frequency_index = r.bits(4)
num_front_channel_elements = r.bits(4)
num_side_channel_elements = r.bits(4)
num_back_channel_elements = r.bits(4)
num_lfe_channel_elements = r.bits(2)
num_assoc_data_elements = r.bits(3)
num_valid_cc_elements = r.bits(4)
mono_mixdown_present = r.bits(1)
if mono_mixdown_present == 1:
r.skip(4)
stereo_mixdown_present = r.bits(1)
if stereo_mixdown_present == 1:
r.skip(4)
matrix_mixdown_idx_present = r.bits(1)
if matrix_mixdown_idx_present == 1:
r.skip(3)
elms = num_front_channel_elements + num_side_channel_elements + \
num_back_channel_elements
channels = 0
for i in xrange(elms):
channels += 1
element_is_cpe = r.bits(1)
if element_is_cpe:
channels += 1
r.skip(4)
channels += num_lfe_channel_elements
self.channels = channels
r.skip(4 * num_lfe_channel_elements)
r.skip(4 * num_assoc_data_elements)
r.skip(5 * num_valid_cc_elements)
r.align()
comment_field_bytes = r.bits(8)
r.skip(8 * comment_field_bytes)
def parse(self, asf, data):
super(CodecListObject, self).parse(asf, data)
offset = 16
count, offset = cdata.uint32_le_from(data, offset)
for i in xrange(count):
try:
offset, type_, name, desc, codec = \
self._parse_entry(data, offset)
except cdata.error:
raise ASFError("invalid codec entry")
# go with the first audio entry
if type_ == 2:
name = name.strip()
desc = desc.strip()
asf.info.codec_type = codec
asf.info.codec_name = name
asf.info.codec_description = desc
return
def parse(self, asf, data):
super(CodecListObject, self).parse(asf, data)
offset = 16
count, offset = cdata.uint32_le_from(data, offset)
for i in xrange(count):
try:
offset, type_, name, desc, codec = \
self._parse_entry(data, offset)
except cdata.error:
raise ASFError("invalid codec entry")
# go with the first audio entry
if type_ == 2:
name = name.strip()
desc = desc.strip()
asf.info.codec_type = codec
asf.info.codec_name = name
asf.info.codec_description = desc
return
