class __GIF__(ImageMetrics):
HEADER = construct.Struct('header',
construct.Const(construct.String('gif',3),'GIF'),
construct.String('version',3))
SCREEN_DESCRIPTOR = construct.Struct('logical_screen_descriptor',
construct.ULInt16('width'),
construct.ULInt16('height'),
construct.Embed(
construct.BitStruct('packed_fields',
construct.Flag('global_color_table'),
construct.Bits('color_resolution',3),
construct.Flag('sort'),
construct.Bits('global_color_table_size',3))),
construct.Byte('background_color_index'),
construct.Byte('pixel_aspect_ratio'))
def __init__(self, width, height, color_count):
ImageMetrics.__init__(self, width, height, 8, color_count, u'image/gif')
@classmethod
def parse(cls, file):
try:
header = cls.HEADER.parse_stream(file)
descriptor = cls.SCREEN_DESCRIPTOR.parse_stream(file)
return __GIF__(descriptor.width, descriptor.height,
2 ** (descriptor.global_color_table_size + 1))
except construct.ConstError:
raise InvalidGIF(_(u'Invalid GIF'))
class __BMP__(ImageMetrics):
HEADER = construct.Struct('bmp_header',
construct.Const(construct.String('magic_number',2),'BM'),
construct.ULInt32('file_size'),
construct.ULInt16('reserved1'),
construct.ULInt16('reserved2'),
construct.ULInt32('bitmap_data_offset'))
INFORMATION = construct.Struct('bmp_information',
construct.ULInt32('header_size'),
construct.ULInt32('width'),
construct.ULInt32('height'),
construct.ULInt16('color_planes'),
construct.ULInt16('bits_per_pixel'),
construct.ULInt32('compression_method'),
construct.ULInt32('image_size'),
construct.ULInt32('horizontal_resolution'),
construct.ULInt32('vertical_resolution'),
construct.ULInt32('colors_used'),
construct.ULInt32('important_colors_used'))
def __init__(self, width, height, bits_per_pixel, color_count):
ImageMetrics.__init__(self, width, height, bits_per_pixel, color_count,
u'image/x-ms-bmp')
@classmethod
def parse(cls, file):
try:
header = cls.HEADER.parse_stream(file)
information = cls.INFORMATION.parse_stream(file)
return __BMP__(information.width, information.height,
information.bits_per_pixel,
information.colors_used)
except construct.ConstError:
raise InvalidBMP(_(u'Invalid BMP'))
def l_tag_value(cls, file, tag):
subtype = {1:construct.Byte("data"),
2:construct.CString("data"),
3:construct.ULInt16("data"),
4:construct.ULInt32("data"),
5:construct.Struct("data",
construct.ULInt32("high"),
construct.ULInt32("low"))}[tag.type]
data = construct.StrictRepeater(tag.count,
subtype)
if ((tag.type != 2) and (data.sizeof() <= 4)):
return tag.offset
else:
file.seek(tag.offset,0)
return data.parse_stream(file)
class ApeAudio(ApeTaggedAudio, AudioFile):
SUFFIX = "ape"
NAME = SUFFIX
DEFAULT_COMPRESSION = "5000"
COMPRESSION_MODES = tuple([str(x * 1000) for x in range(1, 6)])
del (x)
BINARIES = ("mac", )
FILE_HEAD = construct.Struct("ape_head", construct.String('id', 4),
construct.ULInt16('version'))
#version >= 3.98
APE_DESCRIPTOR = construct.Struct(
"ape_descriptor", construct.ULInt16('padding'),
construct.ULInt32('descriptor_bytes'),
construct.ULInt32('header_bytes'),
construct.ULInt32('seektable_bytes'),
construct.ULInt32('header_data_bytes'),
construct.ULInt32('frame_data_bytes'),
construct.ULInt32('frame_data_bytes_high'),
construct.ULInt32('terminating_data_bytes'),
construct.String('md5', 16))
APE_HEADER = construct.Struct("ape_header",
construct.ULInt16('compression_level'),
construct.ULInt16('format_flags'),
construct.ULInt32('blocks_per_frame'),
construct.ULInt32('final_frame_blocks'),
construct.ULInt32('total_frames'),
construct.ULInt16('bits_per_sample'),
construct.ULInt16('number_of_channels'),
construct.ULInt32('sample_rate'))
#version <= 3.97
APE_HEADER_OLD = construct.Struct("ape_header_old",
construct.ULInt16('compression_level'),
construct.ULInt16('format_flags'),
construct.ULInt16('number_of_channels'),
construct.ULInt32('sample_rate'),
construct.ULInt32('header_bytes'),
construct.ULInt32('terminating_bytes'),
construct.ULInt32('total_frames'),
construct.ULInt32('final_frame_blocks'))
def __init__(self, filename):
AudioFile.__init__(self, filename)
(self.__samplespersec__, self.__channels__, self.__bitspersample__,
self.__totalsamples__) = ApeAudio.__ape_info__(filename)
@classmethod
def is_type(cls, file):
return file.read(4) == "MAC "
def lossless(self):
return True
@classmethod
def supports_foreign_riff_chunks(cls):
return True
def has_foreign_riff_chunks(self):
#FIXME - this isn't strictly true
#I'll need a way to detect foreign chunks in APE's stream
#without decoding it first,
#but since I'm not supporting APE anyway, I'll take the lazy way out
return True
def bits_per_sample(self):
return self.__bitspersample__
def channels(self):
return self.__channels__
def total_frames(self):
return self.__totalsamples__
def sample_rate(self):
return self.__samplespersec__
@classmethod
def __ape_info__(cls, filename):
f = file(filename, 'rb')
try:
file_head = cls.FILE_HEAD.parse_stream(f)
if (file_head.id != 'MAC '):
raise InvalidFile(_(u"Invalid Monkey's Audio header"))
if (file_head.version >= 3980): #the latest APE file type
descriptor = cls.APE_DESCRIPTOR.parse_stream(f)
header = cls.APE_HEADER.parse_stream(f)
return (header.sample_rate,
header.number_of_channels,
header.bits_per_sample,
((header.total_frames - 1) * \
header.blocks_per_frame) + \
header.final_frame_blocks)
else: #old-style APE file (obsolete)
header = cls.APE_HEADER_OLD.parse_stream(f)
if (file_head.version >= 3950):
blocks_per_frame = 0x48000
elif ((file_head.version >= 3900)
or ((file_head.version >= 3800) and
(header.compression_level == 4000))):
blocks_per_frame = 0x12000
else:
blocks_per_frame = 0x2400
if (header.format_flags & 0x01):
bits_per_sample = 8
elif (header.format_flags & 0x08):
bits_per_sample = 24
else:
bits_per_sample = 16
return (header.sample_rate,
header.number_of_channels,
bits_per_sample,
((header.total_frames - 1) * \
blocks_per_frame) + \
header.final_frame_blocks)
finally:
f.close()
def to_wave(self, wave_filename):
if (self.filename.endswith(".ape")):
devnull = file(os.devnull, "wb")
sub = subprocess.Popen(
[BIN['mac'], self.filename, wave_filename, '-d'],
stdout=devnull,
stderr=devnull)
sub.wait()
devnull.close()
else:
devnull = file(os.devnull, 'ab')
import tempfile
ape = tempfile.NamedTemporaryFile(suffix='.ape')
f = file(self.filename, 'rb')
transfer_data(f.read, ape.write)
f.close()
ape.flush()
sub = subprocess.Popen([BIN['mac'], ape.name, wave_filename, '-d'],
stdout=devnull,
stderr=devnull)
sub.wait()
ape.close()
devnull.close()
@classmethod
def from_wave(cls, filename, wave_filename, compression=None):
if (str(compression) not in cls.COMPRESSION_MODES):
compression = cls.DEFAULT_COMPRESSION
devnull = file(os.devnull, "wb")
sub = subprocess.Popen(
[BIN['mac'], wave_filename, filename,
"-c%s" % (compression)],
stdout=devnull,
stderr=devnull)
sub.wait()
devnull.close()
return ApeAudio(filename)
class WavPackAudio(ApeTaggedAudio, AudioFile):
SUFFIX = "wv"
NAME = SUFFIX
DEFAULT_COMPRESSION = "veryhigh"
COMPRESSION_MODES = ("fast", "standard", "high", "veryhigh")
BINARIES = ("wavpack", "wvunpack")
APE_TAG_CLASS = WavePackAPEv2
HEADER = construct.Struct(
"wavpackheader", construct.Const(construct.String("id", 4), 'wvpk'),
construct.ULInt32("block_size"), construct.ULInt16("version"),
construct.ULInt8("track_number"), construct.ULInt8("index_number"),
construct.ULInt32("total_samples"), construct.ULInt32("block_index"),
construct.ULInt32("block_samples"),
construct.Embed(
construct.BitStruct("flags", construct.Flag("floating_point_data"),
construct.Flag("hybrid_noise_shaping"),
construct.Flag("cross_channel_decorrelation"),
construct.Flag("joint_stereo"),
construct.Flag("hybrid_mode"),
construct.Flag("mono_output"),
construct.Bits("bits_per_sample", 2),
construct.Bits("left_shift_data_low", 3),
construct.Flag("final_block_in_sequence"),
construct.Flag("initial_block_in_sequence"),
construct.Flag("hybrid_noise_balanced"),
construct.Flag("hybrid_mode_control_bitrate"),
construct.Flag("extended_size_integers"),
construct.Bit("sampling_rate_low"),
construct.Bits("maximum_magnitude", 5),
construct.Bits("left_shift_data_high", 2),
construct.Flag("reserved2"),
construct.Flag("false_stereo"),
construct.Flag("use_IIR"),
construct.Bits("reserved1", 2),
construct.Bits("sampling_rate_high", 3))),
construct.ULInt32("crc"))
SUB_HEADER = construct.Struct(
"wavpacksubheader",
construct.Embed(
construct.BitStruct("flags", construct.Flag("large_block"),
construct.Flag("actual_size_1_less"),
construct.Flag("nondecoder_data"),
construct.Bits("metadata_function", 5))),
construct.IfThenElse('size', lambda ctx: ctx['large_block'],
ULInt24('s'), construct.Byte('s')))
BITS_PER_SAMPLE = (8, 16, 24, 32)
SAMPLING_RATE = (6000, 8000, 9600, 11025, 12000, 16000, 22050, 24000,
32000, 44100, 48000, 64000, 88200, 96000, 192000, 0)
def __init__(self, filename):
self.filename = filename
self.__samplerate__ = 0
self.__channels__ = 0
self.__bitspersample__ = 0
self.__total_frames__ = 0
self.__read_info__()
@classmethod
def is_type(cls, file):
return file.read(4) == 'wvpk'
def lossless(self):
return True
@classmethod
def supports_foreign_riff_chunks(cls):
return True
def channel_mask(self):
fmt_chunk = WaveAudio.FMT_CHUNK.parse(self.__fmt_chunk__())
if (fmt_chunk.compression != 0xFFFE):
if (self.__channels__ == 1):
return ChannelMask.from_fields(front_center=True)
elif (self.__channels__ == 2):
return ChannelMask.from_fields(front_left=True,
front_right=True)
#if we have a multi-channel WavPack file
#that's not WAVEFORMATEXTENSIBLE,
#assume the channels follow SMPTE/ITU-R recommendations
#and hope for the best
elif (self.__channels__ == 3):
return ChannelMask.from_fields(front_left=True,
front_right=True,
front_center=True)
elif (self.__channels__ == 4):
return ChannelMask.from_fields(front_left=True,
front_right=True,
back_left=True,
back_right=True)
elif (self.__channels__ == 5):
return ChannelMask.from_fields(front_left=True,
front_right=True,
back_left=True,
back_right=True,
front_center=True)
elif (self.__channels__ == 6):
return ChannelMask.from_fields(front_left=True,
front_right=True,
back_left=True,
back_right=True,
front_center=True,
low_frequency=True)
else:
return ChannelMask(0)
else:
return WaveAudio.fmt_chunk_to_channel_mask(fmt_chunk.channel_mask)
def get_metadata(self):
metadata = ApeTaggedAudio.get_metadata(self)
if (metadata is not None):
metadata.frame_count = self.total_frames()
return metadata
def has_foreign_riff_chunks(self):
for (sub_header, nondecoder, data) in self.sub_frames():
if ((sub_header == 1) and nondecoder):
return set(__riff_chunk_ids__(data)) != set(['fmt ', 'data'])
else:
return False
def __fmt_chunk__(self):
for (sub_header, nondecoder, data) in self.sub_frames():
if ((sub_header == 1) and nondecoder):
for (chunk_id, chunk_data) in __riff_chunks__(data):
if (chunk_id == 'fmt '):
return chunk_data
else:
return None
def frames(self):
f = file(self.filename)
remaining_samples = None
try:
while ((remaining_samples is None) or (remaining_samples > 0)):
try:
header = WavPackAudio.HEADER.parse(
f.read(WavPackAudio.HEADER.sizeof()))
except construct.ConstError:
raise InvalidFile(_(u'WavPack header ID invalid'))
if (remaining_samples is None):
remaining_samples = (header.total_samples - \
header.block_samples)
else:
remaining_samples -= header.block_samples
data = f.read(header.block_size - 24)
yield (header, data)
finally:
f.close()
def sub_frames(self):
import cStringIO
for (header, data) in self.frames():
total_size = len(data)
data = cStringIO.StringIO(data)
while (data.tell() < total_size):
sub_header = WavPackAudio.SUB_HEADER.parse_stream(data)
if (sub_header.actual_size_1_less):
yield (sub_header.metadata_function,
sub_header.nondecoder_data,
data.read((sub_header.size * 2) - 1))
data.read(1)
else:
yield (sub_header.metadata_function,
sub_header.nondecoder_data,
data.read(sub_header.size * 2))
def __read_info__(self):
f = file(self.filename)
try:
try:
header = WavPackAudio.HEADER.parse(
f.read(WavPackAudio.HEADER.sizeof()))
except construct.ConstError:
raise InvalidFile(_(u'WavPack header ID invalid'))
self.__samplerate__ = WavPackAudio.SAMPLING_RATE[(
header.sampling_rate_high << 1) | header.sampling_rate_low]
self.__bitspersample__ = WavPackAudio.BITS_PER_SAMPLE[
header.bits_per_sample]
self.__total_frames__ = header.total_samples
self.__channels__ = 0
#go through as many headers as necessary
#to count the number of channels
if (header.mono_output):
self.__channels__ += 1
else:
self.__channels__ += 2
while (not header.final_block_in_sequence):
f.seek(header.block_size - 24, 1)
header = WavPackAudio.HEADER.parse(
f.read(WavPackAudio.HEADER.sizeof()))
if (header.mono_output):
self.__channels__ += 1
else:
self.__channels__ += 2
finally:
f.close()
def bits_per_sample(self):
return self.__bitspersample__
def channels(self):
return self.__channels__
def total_frames(self):
return self.__total_frames__
def sample_rate(self):
return self.__samplerate__
@classmethod
def from_pcm(cls, filename, pcmreader, compression=None):
compression_param = {
"fast": ["-f"],
"standard": [],
"high": ["-h"],
"veryhigh": ["-hh"]
}
if (str(compression) not in cls.COMPRESSION_MODES):
compression = cls.DEFAULT_COMPRESSION
if ('--raw-pcm' in cls.__wavpack_help__()):
if (filename.endswith(".wv")):
devnull = file(os.devnull, 'ab')
if (pcmreader.channels > 18):
raise UnsupportedChannelMask()
elif (pcmreader.channels > 2):
order_map = {
"front_left": "FL",
"front_right": "FR",
"front_center": "FC",
"low_frequency": "LFE",
"back_left": "BL",
"back_right": "BR",
"front_left_of_center": "FLC",
"front_right_of_center": "FRC",
"back_center": "BC",
"side_left": "SL",
"side_right": "SR",
"top_center": "TC",
"top_front_left": "TFL",
"top_front_center": "TFC",
"top_front_right": "TFR",
"top_back_left": "TBL",
"top_back_center": "TBC",
"top_back_right": "TBR"
}
channel_order = [
"--channel-order=%s" % (",".join([
order_map[channel] for channel in ChannelMask(
pcmreader.channel_mask).channels()
]))
]
else:
channel_order = []
sub = subprocess.Popen([BIN['wavpack']] + \
compression_param[compression] + \
['-q','-y',
"--raw-pcm=%(sr)s,%(bps)s,%(ch)s"%\
{"sr":pcmreader.sample_rate,
"bps":pcmreader.bits_per_sample,
"ch":pcmreader.channels}] + \
channel_order + \
['-','-o',filename],
stdout=devnull,
stderr=devnull,
stdin=subprocess.PIPE,
preexec_fn=ignore_sigint)
transfer_framelist_data(pcmreader, sub.stdin.write)
devnull.close()
sub.stdin.close()
if (sub.wait() == 0):
return WavPackAudio(filename)
else:
raise EncodingError(BIN['wavpack'])
else:
import tempfile
tempdir = tempfile.mkdtemp()
symlink = os.path.join(tempdir,
os.path.basename(filename) + ".wv")
try:
os.symlink(os.path.abspath(filename), symlink)
cls.from_pcm(symlink, pcmreader, compression)
return WavPackAudio(filename)
finally:
os.unlink(symlink)
os.rmdir(tempdir)
else:
import tempfile
f = tempfile.NamedTemporaryFile(suffix=".wav")
w = WaveAudio.from_pcm(f.name, pcmreader)
try:
return cls.from_wave(filename, w.filename, compression)
finally:
del (w)
f.close()
def to_wave(self, wave_filename):
devnull = file(os.devnull, 'ab')
#WavPack stupidly refuses to run if the filename doesn't end with .wv
if (self.filename.endswith(".wv")):
sub = subprocess.Popen([
BIN['wvunpack'], '-q', '-y', self.filename, '-o', wave_filename
],
stdout=devnull,
stderr=devnull)
if (sub.wait() != 0):
raise EncodingError()
else:
#create a temporary symlink to the current file
#rather than rewrite the whole thing
import tempfile
tempdir = tempfile.mkdtemp()
symlink = os.path.join(tempdir,
os.path.basename(self.filename) + ".wv")
try:
os.symlink(os.path.abspath(self.filename), symlink)
WavPackAudio(symlink).to_wave(wave_filename)
finally:
os.unlink(symlink)
os.rmdir(tempdir)
def to_pcm(self):
if (self.filename.endswith(".wv")):
if ('-r' in WavPackAudio.__wvunpack_help__()):
sub = subprocess.Popen([
BIN['wvunpack'], '-q', '-y', self.filename, '-r', '-o', '-'
],
stdout=subprocess.PIPE,
stderr=file(os.devnull, 'ab'))
return PCMReader(sub.stdout,
sample_rate=self.sample_rate(),
channels=self.channels(),
channel_mask=int(self.channel_mask()),
bits_per_sample=self.bits_per_sample(),
process=sub)
else:
sub = subprocess.Popen(
[BIN['wvunpack'], '-q', '-y', self.filename, '-o', '-'],
stdout=subprocess.PIPE,
stderr=file(os.devnull, 'ab'))
return WaveReader(sub.stdout,
sample_rate=self.sample_rate(),
channels=self.channels(),
channel_mask=int(self.channel_mask()),
bits_per_sample=self.bits_per_sample(),
process=sub)
else:
#create a temporary symlink to the current file
#rather than rewrite the whole thing
(tempdir, symlink) = SymlinkPCMReader.new(self.filename, ".wv")
return SymlinkPCMReader(
WavPackAudio(symlink).to_pcm(), tempdir, symlink)
@classmethod
def from_wave(cls, filename, wave_filename, compression=None):
if (str(compression) not in cls.COMPRESSION_MODES):
compression = cls.DEFAULT_COMPRESSION
compression_param = {
"fast": ["-f"],
"standard": [],
"high": ["-h"],
"veryhigh": ["-hh"]
}
#wavpack will add a .wv suffix if there isn't one
#this isn't desired behavior
if (filename.endswith(".wv")):
devnull = file(os.devnull, 'ab')
sub = subprocess.Popen([BIN['wavpack'],
wave_filename] + \
compression_param[compression] + \
['-q','-y','-o',
filename],
stdout=devnull,
stderr=devnull,
preexec_fn=ignore_sigint)
devnull.close()
if (sub.wait() == 0):
return WavPackAudio(filename)
else:
raise EncodingError(BIN['wavpack'])
else:
import tempfile
tempdir = tempfile.mkdtemp()
symlink = os.path.join(tempdir, os.path.basename(filename) + ".wv")
try:
os.symlink(os.path.abspath(filename), symlink)
cls.from_wave(symlink, wave_filename, compression)
return WavPackAudio(filename)
finally:
os.unlink(symlink)
os.rmdir(tempdir)
@classmethod
def __wavpack_help__(cls):
devnull = open(os.devnull, "wb")
sub = subprocess.Popen([BIN["wavpack"], "--help"],
stdout=subprocess.PIPE,
stderr=devnull)
help_data = sub.stdout.read()
sub.stdout.close()
devnull.close()
sub.wait()
return help_data
@classmethod
def __wvunpack_help__(cls):
devnull = open(os.devnull, "wb")
sub = subprocess.Popen([BIN["wvunpack"], "--help"],
stdout=subprocess.PIPE,
stderr=devnull)
help_data = sub.stdout.read()
sub.stdout.close()
devnull.close()
sub.wait()
return help_data
@classmethod
def add_replay_gain(cls, filenames):
track_names = [
track.filename for track in open_files(filenames)
if isinstance(track, cls)
]
if ((len(track_names) > 0) and BIN.can_execute(BIN['wvgain'])):
devnull = file(os.devnull, 'ab')
sub = subprocess.Popen([BIN['wvgain'], '-q', '-a'] + track_names,
stdout=devnull,
stderr=devnull)
sub.wait()
devnull.close()
@classmethod
def can_add_replay_gain(cls):
return BIN.can_execute(BIN['wvgain'])
@classmethod
def lossless_replay_gain(cls):
return True
def replay_gain(self):
metadata = self.get_metadata()
if (metadata is None):
return None
if (set([
'replaygain_track_gain', 'replaygain_track_peak',
'replaygain_album_gain', 'replaygain_album_peak'
]).issubset(metadata.keys())): #we have ReplayGain data
try:
return ReplayGain(
unicode(metadata['replaygain_track_gain'])[0:-len(" dB")],
unicode(metadata['replaygain_track_peak']),
unicode(metadata['replaygain_album_gain'])[0:-len(" dB")],
unicode(metadata['replaygain_album_peak']))
except ValueError:
return None
else:
return None
def get_cuesheet(self):
import cue
metadata = self.get_metadata()
if ((metadata is not None) and ('Cuesheet' in metadata.keys())):
try:
return cue.parse(
cue.tokens(
unicode(metadata['Cuesheet']).encode(
'utf-8', 'replace')))
except cue.CueException:
#unlike FLAC, just because a cuesheet is embedded
#does not mean it is compliant
return None
else:
return None
def set_cuesheet(self, cuesheet):
import os.path
import cue
if (cuesheet is None):
return
metadata = self.get_metadata()
if (metadata is None):
metadata = WavePackAPEv2.converted(MetaData())
metadata['Cuesheet'] = WavePackAPEv2.ITEM.string(
'Cuesheet',
cue.Cuesheet.file(cuesheet,
os.path.basename(self.filename)).decode(
'ascii', 'replace'))
self.set_metadata(metadata)
class __TIFF__(ImageMetrics):
HEADER = construct.Struct('header',
construct.String('byte_order',2),
construct.Switch('order',
lambda ctx: ctx['byte_order'],
{"II":construct.Embed(
construct.Struct('little_endian',
construct.Const(construct.ULInt16('version'),42),
construct.ULInt32('offset'))),
"MM":construct.Embed(
construct.Struct('big_endian',
construct.Const(construct.UBInt16('version'),42),
construct.UBInt32('offset')))}))
L_IFD = construct.Struct('ifd',
construct.PrefixedArray(
length_field=construct.ULInt16('length'),
subcon=construct.Struct('tags',
construct.ULInt16('id'),
construct.ULInt16('type'),
construct.ULInt32('count'),
construct.ULInt32('offset'))),
construct.ULInt32('next'))
B_IFD = construct.Struct('ifd',
construct.PrefixedArray(
length_field=construct.UBInt16('length'),
subcon=construct.Struct('tags',
construct.UBInt16('id'),
construct.UBInt16('type'),
construct.UBInt32('count'),
construct.UBInt32('offset'))),
construct.UBInt32('next'))
def __init__(self, width, height, bits_per_pixel, color_count):
ImageMetrics.__init__(self, width, height,
bits_per_pixel, color_count,
u'image/tiff')
@classmethod
def b_tag_value(cls, file, tag):
subtype = {1:construct.Byte("data"),
2:construct.CString("data"),
3:construct.UBInt16("data"),
4:construct.UBInt32("data"),
5:construct.Struct("data",
construct.UBInt32("high"),
construct.UBInt32("low"))}[tag.type]
data = construct.StrictRepeater(tag.count,
subtype)
if ((tag.type != 2) and (data.sizeof() <= 4)):
return tag.offset
else:
file.seek(tag.offset,0)
return data.parse_stream(file)
@classmethod
def l_tag_value(cls, file, tag):
subtype = {1:construct.Byte("data"),
2:construct.CString("data"),
3:construct.ULInt16("data"),
4:construct.ULInt32("data"),
5:construct.Struct("data",
construct.ULInt32("high"),
construct.ULInt32("low"))}[tag.type]
data = construct.StrictRepeater(tag.count,
subtype)
if ((tag.type != 2) and (data.sizeof() <= 4)):
return tag.offset
else:
file.seek(tag.offset,0)
return data.parse_stream(file)
@classmethod
def parse(cls, file):
width = 0
height = 0
bits_per_sample = 0
color_count = 0
try:
header = cls.HEADER.parse_stream(file)
if (header.byte_order == 'II'):
IFD = cls.L_IFD
tag_value = cls.l_tag_value
elif (header.byte_order == 'MM'):
IFD = cls.B_IFD
tag_value = cls.b_tag_value
else:
raise InvalidTIFF(_(u'Invalid byte order'))
file.seek(header.offset,0)
ifd = IFD.parse_stream(file)
while (True):
for tag in ifd.tags:
if (tag.id == 0x0100):
width = tag_value(file,tag)
elif (tag.id == 0x0101):
height = tag_value(file,tag)
elif (tag.id == 0x0102):
try:
bits_per_sample = sum(tag_value(file,tag))
except TypeError:
bits_per_sample = tag_value(file,tag)
elif (tag.id == 0x0140):
color_count = tag.count / 3
else:
pass
if (ifd.next == 0x00):
break
else:
file.seek(ifd.next,0)
ifd = IFD.parse_stream(file)
return __TIFF__(width,height,bits_per_sample,color_count)
except construct.ConstError:
raise InvalidTIFF(_(u'Invalid TIFF'))