def delete_metadata(self):
"""Deletes the track's MetaData.
This removes or unsets tags as necessary in order to remove all data.
Raises IOError if unable to write the file."""
import tempfile
new_aiff = tempfile.TemporaryFile()
new_aiff.seek(12, 0)
for (chunk_id, chunk_length, chunk_file) in self.chunk_files():
if (chunk_id != 'ID3 '):
new_aiff.write(
self.CHUNK_HEADER.build(
Con.Container(chunk_id=chunk_id,
chunk_length=chunk_length)))
transfer_data(chunk_file.read, new_aiff.write)
header = Con.Container(aiff_id='FORM',
aiff_size=new_aiff.tell() - 8,
aiff_type='AIFF')
new_aiff.seek(0, 0)
new_aiff.write(self.AIFF_HEADER.build(header))
new_aiff.seek(0, 0)
f = open(self.filename, 'wb')
transfer_data(new_aiff.read, f.write)
new_aiff.close()
f.close()
def set_metadata(self, metadata):
"""Takes a MetaData object and sets this track's metadata.
This metadata includes track name, album name, and so on.
Raises IOError if unable to write the file."""
if (metadata is None):
return
import tempfile
id3_chunk = ID3v22Comment.converted(metadata).build()
new_aiff = tempfile.TemporaryFile()
new_aiff.seek(12, 0)
id3_found = False
for (chunk_id, chunk_length, chunk_file) in self.chunk_files():
if (chunk_id != 'ID3 '):
new_aiff.write(
self.CHUNK_HEADER.build(
Con.Container(chunk_id=chunk_id,
chunk_length=chunk_length)))
transfer_data(chunk_file.read, new_aiff.write)
else:
new_aiff.write(
self.CHUNK_HEADER.build(
Con.Container(chunk_id='ID3 ',
chunk_length=len(id3_chunk))))
new_aiff.write(id3_chunk)
id3_found = True
if (not id3_found):
new_aiff.write(
self.CHUNK_HEADER.build(
Con.Container(chunk_id='ID3 ',
chunk_length=len(id3_chunk))))
new_aiff.write(id3_chunk)
header = Con.Container(aiff_id='FORM',
aiff_size=new_aiff.tell() - 8,
aiff_type='AIFF')
new_aiff.seek(0, 0)
new_aiff.write(self.AIFF_HEADER.build(header))
new_aiff.seek(0, 0)
f = open(self.filename, 'wb')
transfer_data(new_aiff.read, f.write)
new_aiff.close()
f.close()
def from_pcm(cls, filename, pcmreader, compression=None):
"""Encodes a new file from PCM data.
Takes a filename string, PCMReader object
and optional compression level string.
Encodes a new audio file from pcmreader's data
at the given filename with the specified compression level
and returns a new AuAudio object."""
if (pcmreader.bits_per_sample not in (8, 16, 24)):
raise InvalidFormat(
_(u"Unsupported bits per sample %s") %
(pcmreader.bits_per_sample))
bytes_per_sample = pcmreader.bits_per_sample / 8
header = Con.Container(magic_number='.snd',
data_offset=0,
data_size=0,
encoding_format={
8: 2,
16: 3,
24: 4
}[pcmreader.bits_per_sample],
sample_rate=pcmreader.sample_rate,
channels=pcmreader.channels)
try:
f = file(filename, 'wb')
except IOError, err:
raise EncodingError(str(err))
def __str__(self):
def __count_digits__(i):
if (i == 0):
return 0
else:
return (i % 10) + __count_digits__(i / 10)
disc_id = Con.Container()
disc_id.track_count = len(self.tracks)
disc_id.length = self.length() / 75
disc_id.digit_sum = sum(
[__count_digits__(o / 75) for o in self.offsets()]) % 0xFF
return DiscID.DISCID.build(disc_id).encode('hex')
def build(self):
"""Returns this VorbisComment as a binary string."""
comment = Con.Container(vendor_string=self.vendor_string,
framing=1,
value=[])
for (key, values) in self.items():
for value in values:
if ((value != u"")
and not ((key in ("TRACKNUMBER", "TRACKTOTAL",
"DISCNUMBER", "DISCTOTAL")) and
(value == u"0"))):
comment.value.append("%s=%s" %
(key, value.encode('utf-8')))
return self.VORBIS_COMMENT.build(comment)
def _encode(self, value, context):
import math
if (value < 0):
signed = True
value *= -1
else:
signed = False
(fmant, exponent) = math.frexp(value)
if ((exponent > 16384) or (fmant >= 1)):
exponent = 0x7FFF
mantissa = 0
else:
exponent += 16382
mantissa = fmant * (2**64)
return Con.Container(signed=signed,
exponent=exponent,
mantissa=mantissa)
def build_id3v1(cls, song_title, artist, album, year, comment,
track_number):
"""Turns fields into a complete ID3v1 binary tag string.
All fields are unicode except for track_number, an int."""
def __s_pad__(s, length):
if (len(s) < length):
return s + chr(0) * (length - len(s))
else:
s = s[0:length].rstrip()
return s + chr(0) * (length - len(s))
c = Con.Container()
c.identifier = 'TAG'
c.song_title = __s_pad__(song_title.encode('ascii', 'replace'), 30)
c.artist = __s_pad__(artist.encode('ascii', 'replace'), 30)
c.album = __s_pad__(album.encode('ascii', 'replace'), 30)
c.year = __s_pad__(year.encode('ascii', 'replace'), 4)
c.comment = __s_pad__(comment.encode('ascii', 'replace'), 28)
c.track_number = int(track_number)
c.genre = 0
return ID3v1Comment.ID3v1.build(c)
if (int(pcmreader.channel_mask) in (
0x4, # FC
0x3, # FL, FR
0x7, # FL, FR, FC
0x33, # FL, FR, BL, BR
0x707)): # FL, SL, FC, FR, SR, BC
standard_channel_mask = ChannelMask(pcmreader.channel_mask)
aiff_channel_mask = AIFFChannelMask(standard_channel_mask)
pcmreader = ReorderedPCMReader(pcmreader, [
standard_channel_mask.channels().index(channel)
for channel in aiff_channel_mask.channels()
])
try:
aiff_header = Con.Container(aiff_id='FORM',
aiff_size=4,
aiff_type='AIFF')
comm_chunk = Con.Container(channels=pcmreader.channels,
total_sample_frames=0,
sample_size=pcmreader.bits_per_sample,
sample_rate=float(
pcmreader.sample_rate))
ssnd_header = Con.Container(chunk_id='SSND', chunk_length=0)
ssnd_alignment = Con.Container(offset=0, blocksize=0)
#skip ahead to the start of the SSND chunk
f.seek(
cls.AIFF_HEADER.sizeof() + cls.CHUNK_HEADER.sizeof() +
cls.COMM_CHUNK.sizeof() + cls.CHUNK_HEADER.sizeof(), 0)
def _build(self, obj, stream, context):
data = self.sub_atom.build(obj)
stream.write(
self.header.build(
Con.Container(type=self.atom_name, size=len(data) + 8)))
stream.write(data)
def set_metadata(self, metadata):
"""Takes a MetaData object and sets this track's metadata.
This metadata includes track name, album name, and so on.
Raises IOError if unable to write the file."""
metadata = VorbisComment.converted(metadata)
if (metadata is None):
return
reader = OggStreamReader(file(self.filename, 'rb'))
new_file = cStringIO.StringIO()
writer = OggStreamWriter(new_file)
current_sequence_number = 0
pages = reader.pages()
#transfer our old header
#this must always be the first packet and the first page
(header_page, header_data) = pages.next()
writer.write_page(header_page, header_data)
current_sequence_number += 1
#grab the current "comment" and "setup headers" packets
#these may take one or more pages,
#but will always end on a page boundary
del (pages)
packets = reader.packets(from_beginning=False)
comment_packet = packets.next()
headers_packet = packets.next()
#write the pages for our new "comment" packet
for (page, data) in OggStreamWriter.build_pages(
0, header_page.bitstream_serial_number,
current_sequence_number,
VorbisAudio.COMMENT_HEADER.build(
Con.Container(packet_type=3, vorbis='vorbis')) +
metadata.build()):
writer.write_page(page, data)
current_sequence_number += 1
#write the pages for the old "setup headers" packet
for (page, data) in OggStreamWriter.build_pages(
0, header_page.bitstream_serial_number,
current_sequence_number, headers_packet):
writer.write_page(page, data)
current_sequence_number += 1
#write the rest of the pages, re-sequenced and re-checksummed
del (packets)
pages = reader.pages(from_beginning=False)
for (i, (page, data)) in enumerate(pages):
page.page_sequence_number = i + current_sequence_number
page.checksum = OggStreamReader.calculate_ogg_checksum(page, data)
writer.write_page(page, data)
reader.close()
#re-write the file with our new data in "new_file"
f = file(self.filename, "wb")
f.write(new_file.getvalue())
f.close()
writer.close()
self.__read_metadata__()
def build_pages(cls,
granule_position,
serial_number,
starting_sequence_number,
packet_data,
header_type=0):
"""Constructs an Ogg packet for page data.
takes serial_number, granule_position and starting_sequence_number
integers and a packet_data string.
Returns a list of (page_header,page_data) tuples containing
all of the Ogg pages necessary to contain the packet.
"""
page = Con.Container(magic_number='OggS',
version=0,
header_type=header_type,
granule_position=granule_position,
bitstream_serial_number=serial_number,
page_sequence_number=starting_sequence_number,
checksum=0)
if (len(packet_data) == 0):
#an empty Ogg page, but possibly a continuation
page.segments = 0
page.segment_lengths = []
page.checksum = OggStreamReader.calculate_ogg_checksum(
page, packet_data)
return [(page, "")]
if (len(packet_data) > (255 * 255)):
#if we need more than one Ogg page to store the packet,
#handle that case recursively
page.segments = 255
page.segment_lengths = [255] * 255
page.checksum = OggStreamReader.calculate_ogg_checksum(
page, packet_data[0:255 * 255])
return [(page, packet_data[0:255 * 255])] + \
cls.build_pages(granule_position,
serial_number,
starting_sequence_number + 1,
packet_data[255 * 255:],
header_type)
elif (len(packet_data) == (255 * 255)):
#we need two Ogg pages, one of which is empty
return cls.build_pages(granule_position,
serial_number,
starting_sequence_number,
packet_data,
header_type) + \
cls.build_pages(granule_position,
serial_number,
starting_sequence_number + 1,
"",
header_type)
else:
#we just need one Ogg page
page.segments = len(packet_data) / 255
if ((len(packet_data) % 255) > 0):
page.segments += 1
page.segment_lengths = [255] * (len(packet_data) / 255)
if ((len(packet_data) % 255) > 0):
page.segment_lengths += [len(packet_data) % 255]
page.checksum = OggStreamReader.calculate_ogg_checksum(
page, packet_data)
return [(page, packet_data)]
