def verify(self, progress=None):
"""verifies the current file for correctness
returns True if the file is okay
raises an InvalidFile with an error message if there is
some problem with the file"""
# Checking for a truncated Ogg stream typically involves
# verifying that the "end of stream" flag is set on the last
# Ogg page in the stream in the event that one or more whole
# pages is lost. But since the OpusFile decoder doesn't perform
# this check and doesn't provide any access to its internal
# Ogg decoder (unlike Vorbis), we'll perform that check externally.
#
# And since it's a fast check, we won't bother to update progress.
from audiotools.ogg import PageReader
import os.path
try:
reader = PageReader(open(self.filename, "rb"))
except IOError as err:
raise InvalidOpus(str(err))
try:
page = reader.read()
while (not page.stream_end):
page = reader.read()
reader.close()
except (IOError, ValueError) as err:
raise InvalidOpus(str(err))
return AudioFile.verify(self, progress)
def get_metadata(self):
"""returns a MetaData object, or None
raises IOError if unable to read the file"""
from cStringIO import StringIO
from audiotools.bitstream import BitstreamReader
from audiotools.ogg import PacketReader, PageReader
from audiotools.vorbiscomment import VorbisComment
reader = PacketReader(PageReader(open(self.filename, "rb")))
identification = reader.read_packet()
comment = BitstreamReader(StringIO(reader.read_packet()), True)
(packet_type, packet_header) = comment.parse("8u 6b")
if ((packet_type == 3) and (packet_header == 'vorbis')):
vendor_string = \
comment.read_bytes(comment.read(32)).decode('utf-8')
comment_strings = [
comment.read_bytes(comment.read(32)).decode('utf-8')
for i in xrange(comment.read(32))]
if (comment.read(1) == 1): # framing bit
return VorbisComment(comment_strings, vendor_string)
else:
return None
else:
return None
def get_metadata(self):
"""returns a MetaData object, or None
raises IOError if unable to read the file"""
from io import BytesIO
from audiotools.bitstream import BitstreamReader
from audiotools.ogg import PacketReader, PageReader
reader = PacketReader(PageReader(open(self.filename, "rb")))
identification = reader.read_packet()
comment = BitstreamReader(BytesIO(reader.read_packet()), True)
if (comment.read_bytes(8) == "OpusTags"):
vendor_string = \
comment.read_bytes(comment.read(32)).decode('utf-8')
comment_strings = [
comment.read_bytes(comment.read(32)).decode('utf-8')
for i in range(comment.read(32))
]
return VorbisComment(comment_strings, vendor_string)
else:
return None
def total_frames(self):
"""returns the total PCM frames of the track as an integer"""
from audiotools._ogg import PageReader
try:
reader = PageReader(file(self.filename, "rb"))
page = reader.read()
pcm_samples = page.granule_position
while (not page.stream_end):
page = reader.read()
pcm_samples = max(pcm_samples, page.granule_position)
reader.close()
return pcm_samples
except (IOError, ValueError):
return 0
def verify(self, progress=None):
"""verifies the current file for correctness
returns True if the file is okay
raises an InvalidFile with an error message if there is
some problem with the file"""
# Checking for a truncated Ogg stream typically involves
# verifying that the "end of stream" flag is set on the last
# Ogg page in the stream in the event that one or more whole
# pages is lost. But since the OpusFile decoder doesn't perform
# this check and doesn't provide any access to its internal
# Ogg decoder (unlike Vorbis), we'll perform that check externally.
#
# And since it's a fast check, we won't bother to update progress.
from audiotools.ogg import PageReader
import os.path
try:
reader = PageReader(open(self.filename, "rb"))
except IOError as err:
raise InvalidOpus(str(err))
try:
page = reader.read()
while (not page.stream_end):
page = reader.read()
reader.close()
except (IOError, ValueError) as err:
raise InvalidOpus(str(err))
return AudioFile.verify(self, progress)
def total_frames(self):
"""returns the total PCM frames of the track as an integer"""
from audiotools._ogg import PageReader
try:
with PageReader(open(self.filename, "rb")) as reader:
page = reader.read()
pcm_samples = page.granule_position
while not page.stream_end:
page = reader.read()
pcm_samples = max(pcm_samples, page.granule_position)
return pcm_samples
except (IOError, ValueError):
return 0
def update_metadata(self, metadata):
"""takes this track's current MetaData object
as returned by get_metadata() and sets this track's metadata
with any fields updated in that object
raises IOError if unable to write the file
"""
import os
from audiotools import TemporaryFile
from audiotools.ogg import (PageReader,
PacketReader,
PageWriter,
packet_to_pages,
packets_to_pages)
from audiotools.vorbiscomment import VorbisComment
from audiotools.bitstream import BitstreamRecorder
if (metadata is None):
return
elif (not isinstance(metadata, VorbisComment)):
from .text import ERR_FOREIGN_METADATA
raise ValueError(ERR_FOREIGN_METADATA)
elif (not os.access(self.filename, os.W_OK)):
raise IOError(self.filename)
original_ogg = PacketReader(PageReader(file(self.filename, "rb")))
new_ogg = PageWriter(TemporaryFile(self.filename))
sequence_number = 0
#transfer current file's identification packet in its own page
identification_packet = original_ogg.read_packet()
for (i, page) in enumerate(packet_to_pages(
identification_packet,
self.__serial_number__,
starting_sequence_number=sequence_number)):
page.stream_beginning = (i == 0)
new_ogg.write(page)
sequence_number += 1
#discard the current file's comment packet
comment_packet = original_ogg.read_packet()
#generate new comment packet
comment_writer = BitstreamRecorder(True)
comment_writer.build("8u 6b", (3, "vorbis"))
vendor_string = metadata.vendor_string.encode('utf-8')
comment_writer.build("32u %db" % (len(vendor_string)),
(len(vendor_string), vendor_string))
comment_writer.write(32, len(metadata.comment_strings))
for comment_string in metadata.comment_strings:
comment_string = comment_string.encode('utf-8')
comment_writer.build("32u %db" % (len(comment_string)),
(len(comment_string), comment_string))
comment_writer.build("1u a", (1,)) # framing bit
#transfer codebooks packet from original file to new file
codebooks_packet = original_ogg.read_packet()
for page in packets_to_pages(
[comment_writer.data(), codebooks_packet],
self.__serial_number__,
starting_sequence_number=sequence_number):
new_ogg.write(page)
sequence_number += 1
#transfer remaining pages after re-sequencing
page = original_ogg.read_page()
page.sequence_number = sequence_number
sequence_number += 1
new_ogg.write(page)
while (not page.stream_end):
page = original_ogg.read_page()
page.sequence_number = sequence_number
page.bitstream_serial_number = self.__serial_number__
sequence_number += 1
new_ogg.write(page)
original_ogg.close()
new_ogg.close()