def build(self, writer):
"""outputs an APEv2 tag to writer"""
from audiotools.bitstream import BitstreamRecorder
tags = BitstreamRecorder(1)
for tag in self.tags:
tag.build(tags)
if (self.contains_header):
writer.build(ApeTag.HEADER_FORMAT,
("APETAGEX", # preamble
2000, # version
tags.bytes() + 32, # tag size
len(self.tags), # item count
0, # read only
0, # encoding
1, # is header
not self.contains_footer, # no footer
self.contains_header)) # has header
tags.copy(writer)
if (self.contains_footer):
writer.build(ApeTag.HEADER_FORMAT,
("APETAGEX", # preamble
2000, # version
tags.bytes() + 32, # tag size
len(self.tags), # item count
0, # read only
0, # encoding
0, # is header
not self.contains_footer, # no footer
self.contains_header)) # has header
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
"""
from audiotools import transfer_data, TemporaryFile
from audiotools.id3 import ID3v22Comment
from audiotools.bitstream import BitstreamRecorder
from audiotools.text import ERR_FOREIGN_METADATA
import os
if metadata is None:
return
elif not isinstance(metadata, ID3v22Comment):
raise ValueError(ERR_FOREIGN_METADATA)
elif not os.access(self.filename, os.W_OK):
raise IOError(self.filename)
# turn our ID3v2.2 tag into a raw binary chunk
id3_chunk = BitstreamRecorder(0)
metadata.build(id3_chunk)
# generate a temporary AIFF file in which our new ID3v2.2 chunk
# replaces the existing ID3v2.2 chunk
new_aiff = TemporaryFile(self.filename)
self.__class__.aiff_from_chunks(
new_aiff, [(chunk if chunk.id != b"ID3 " else AIFF_Chunk(
b"ID3 ", id3_chunk.bytes(), id3_chunk.data()))
for chunk in self.chunks()])
new_aiff.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"""
from audiotools.id3 import ID3v22Comment
if metadata is None:
return self.delete_metadata()
elif self.get_metadata() is not None:
# current file has metadata, so replace it with new metadata
self.update_metadata(ID3v22Comment.converted(metadata))
else:
# current file has no metadata, so append new ID3 block
import os
from audiotools.bitstream import BitstreamRecorder
from audiotools import transfer_data, TemporaryFile
if not os.access(self.filename, os.W_OK):
raise IOError(self.filename)
# turn our ID3v2.2 tag into a raw binary chunk
id3_chunk = BitstreamRecorder(0)
ID3v22Comment.converted(metadata).build(id3_chunk)
# generate a temporary AIFF file in which our new ID3v2.2 chunk
# is appended to the file's set of chunks
new_aiff = TemporaryFile(self.filename)
self.__class__.aiff_from_chunks(
new_aiff, [c for c in self.chunks()] +
[AIFF_Chunk(b"ID3 ", id3_chunk.bytes(), id3_chunk.data())])
new_aiff.close()
def build(self, writer):
"""outputs an APEv2 tag to writer"""
from audiotools.bitstream import BitstreamRecorder
tags = BitstreamRecorder(1)
for tag in self.tags:
tag.build(tags)
if (self.contains_header):
writer.build(
ApeTag.HEADER_FORMAT,
(
"APETAGEX", # preamble
2000, # version
tags.bytes() + 32, # tag size
len(self.tags), # item count
0, # read only
0, # encoding
1, # is header
not self.contains_footer, # no footer
self.contains_header)) # has header
tags.copy(writer)
if (self.contains_footer):
writer.build(
ApeTag.HEADER_FORMAT,
(
"APETAGEX", # preamble
2000, # version
tags.bytes() + 32, # tag size
len(self.tags), # item count
0, # read only
0, # encoding
0, # is header
not self.contains_footer, # no footer
self.contains_header)) # has header
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
"""
from audiotools import transfer_data, TemporaryFile
from audiotools.id3 import ID3v22Comment
from audiotools.bitstream import BitstreamRecorder
from audiotools.text import ERR_FOREIGN_METADATA
import os
if metadata is None:
return
elif not isinstance(metadata, ID3v22Comment):
raise ValueError(ERR_FOREIGN_METADATA)
elif not os.access(self.filename, os.W_OK):
raise IOError(self.filename)
# turn our ID3v2.2 tag into a raw binary chunk
id3_chunk = BitstreamRecorder(0)
metadata.build(id3_chunk)
# generate a temporary AIFF file in which our new ID3v2.2 chunk
# replaces the existing ID3v2.2 chunk
new_aiff = TemporaryFile(self.filename)
self.__class__.aiff_from_chunks(
new_aiff,
[(chunk if chunk.id != b"ID3 " else
AIFF_Chunk(b"ID3 ",
id3_chunk.bytes(),
id3_chunk.data())) for chunk in self.chunks()])
new_aiff.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"""
from audiotools.id3 import ID3v22Comment
if metadata is None:
return self.delete_metadata()
elif self.get_metadata() is not None:
# current file has metadata, so replace it with new metadata
self.update_metadata(ID3v22Comment.converted(metadata))
else:
# current file has no metadata, so append new ID3 block
import os
from audiotools.bitstream import BitstreamRecorder
from audiotools import transfer_data, TemporaryFile
if not os.access(self.filename, os.W_OK):
raise IOError(self.filename)
# turn our ID3v2.2 tag into a raw binary chunk
id3_chunk = BitstreamRecorder(0)
ID3v22Comment.converted(metadata).build(id3_chunk)
# generate a temporary AIFF file in which our new ID3v2.2 chunk
# is appended to the file's set of chunks
new_aiff = TemporaryFile(self.filename)
self.__class__.aiff_from_chunks(
new_aiff,
[c for c in self.chunks()] + [AIFF_Chunk(b"ID3 ",
id3_chunk.bytes(),
id3_chunk.data())])
new_aiff.close()
def encode_flac(filename,
pcmreader,
block_size=4096,
max_lpc_order=8,
min_residual_partition_order=0,
max_residual_partition_order=5,
mid_side=True,
adaptive_mid_side=False,
exhaustive_model_search=False,
disable_verbatim_subframes=False,
disable_constant_subframes=False,
disable_fixed_subframes=False,
disable_lpc_subframes=False,
padding_size=4096):
frame_sizes = []
options = Encoding_Options(block_size, max_lpc_order, adaptive_mid_side,
mid_side, exhaustive_model_search,
max_residual_partition_order,
14 if pcmreader.bits_per_sample <= 16 else 30)
streaminfo = STREAMINFO(block_size, block_size, (2**24) - 1, 0,
pcmreader.sample_rate, pcmreader.channels,
pcmreader.bits_per_sample, 0, md5())
pcmreader = BufferedPCMReader(pcmreader)
output_file = open(filename, "wb")
writer = BitstreamWriter(output_file, False)
# write placeholder metadata blocks such as STREAMINFO and PADDING
writer.write_bytes("fLaC")
writer.build("1u 7u 24u", [0, 0, 34])
streaminfo_start = writer.getpos()
streaminfo.write(writer)
writer.build("1u 7u 24u", [1, 1, padding_size])
writer.write_bytes(b"\x00" * padding_size)
# walk through PCM reader's FrameLists
frame_number = 0
frame = pcmreader.read(block_size)
flac_frame = BitstreamRecorder(0)
while len(frame) > 0:
streaminfo.input_update(frame)
flac_frame.reset()
encode_flac_frame(flac_frame, pcmreader, options, frame_number, frame)
frame_sizes.append((flac_frame.bytes(), frame.frames))
streaminfo.output_update(flac_frame)
flac_frame.copy(writer)
frame_number += 1
frame = pcmreader.read(block_size)
# return to beginning of file and rewrite STREAMINFO block
writer.setpos(streaminfo_start)
streaminfo.write(writer)
writer.flush()
writer.close()
return frame_sizes
def write_block(writer, context, channels, block_index, first_block, last_block, parameters):
"""writer is a BitstreamWriter-compatible object
context is an EncoderContext object
channels[c][s] is sample "s" in channel "c"
block_index is an integer of the block's offset in PCM frames
first_block and last_block are flags indicating the block's sequence
parameters is an EncodingParameters object
"""
assert (len(channels) == 1) or (len(channels) == 2)
if (len(channels) == 1) or (channels[0] == channels[1]):
# 1 channel block or equivalent
if len(channels) == 1:
false_stereo = 0
else:
false_stereo = 1
# calculate maximum magnitude of channel_0
magnitude = max(map(bits, channels[0]))
# determine wasted bits
wasted = min(map(wasted_bps, channels[0]))
if wasted == INFINITY:
# all samples are 0
wasted = 0
# if wasted bits, remove them from channel_0
if (wasted > 0) and (wasted != INFINITY):
shifted = [[s >> wasted for s in channels[0]]]
else:
shifted = [channels[0]]
# calculate CRC of shifted_0
crc = calculate_crc(shifted)
else:
# 2 channel block
false_stereo = 0
# calculate maximum magnitude of channel_0/channel_1
magnitude = max(max(map(bits, channels[0])), max(map(bits, channels[1])))
# determine wasted bits
wasted = min(min(map(wasted_bps, channels[0])), min(map(wasted_bps, channels[1])))
if wasted == INFINITY:
# all samples are 0
wasted = 0
# if wasted bits, remove them from channel_0/channel_1
if wasted > 0:
shifted = [[s >> wasted for s in channels[0]], [s >> wasted for s in channels[1]]]
else:
shifted = channels
# calculate CRC of shifted_0/shifted_1
crc = calculate_crc(shifted)
# joint stereo conversion of shifted_0/shifted_1 to mid/side channels
mid_side = joint_stereo(shifted[0], shifted[1])
sub_blocks = BitstreamRecorder(1)
sub_block = BitstreamRecorder(1)
# if first block in file, write Wave header
if not context.first_block_written:
sub_block.reset()
if context.wave_header is None:
if context.wave_footer is None:
write_wave_header(sub_block, context.pcmreader, 0, 0)
else:
write_wave_header(sub_block, context.pcmreader, 0, len(context.wave_footer))
else:
sub_block.write_bytes(context.wave_header)
write_sub_block(sub_blocks, WV_WAVE_HEADER, 1, sub_block)
context.first_block_written = True
# if correlation passes, write three sub blocks of pass data
if parameters.correlation_passes > 0:
sub_block.reset()
write_correlation_terms(
sub_block,
[p.term for p in parameters.correlation_parameters(false_stereo)],
[p.delta for p in parameters.correlation_parameters(false_stereo)],
)
write_sub_block(sub_blocks, WV_TERMS, 0, sub_block)
sub_block.reset()
write_correlation_weights(sub_block, [p.weights for p in parameters.correlation_parameters(false_stereo)])
write_sub_block(sub_blocks, WV_WEIGHTS, 0, sub_block)
sub_block.reset()
write_correlation_samples(
sub_block,
[p.term for p in parameters.correlation_parameters(false_stereo)],
[p.samples for p in parameters.correlation_parameters(false_stereo)],
2 if ((len(channels) == 2) and (not false_stereo)) else 1,
)
write_sub_block(sub_blocks, WV_SAMPLES, 0, sub_block)
# if wasted bits, write extended integers sub block
if wasted > 0:
sub_block.reset()
write_extended_integers(sub_block, 0, wasted, 0, 0)
write_sub_block(sub_blocks, WV_INT32_INFO, 0, sub_block)
# if channel count > 2, write channel info sub block
if context.pcmreader.channels > 2:
sub_block.reset()
sub_block.write(8, context.pcmreader.channels)
sub_block.write(32, context.pcmreader.channel_mask)
write_sub_block(sub_blocks, WV_CHANNEL_INFO, 0, sub_block)
# if nonstandard sample rate, write sample rate sub block
if context.pcmreader.sample_rate not in (
6000,
8000,
9600,
11025,
12000,
16000,
22050,
24000,
32000,
44100,
48000,
64000,
88200,
96000,
192000,
):
sub_block.reset()
sub_block.write(32, context.pcmreader.sample_rate)
write_sub_block(sub_blocks, WV_SAMPLE_RATE, 1, sub_block)
if (len(channels) == 1) or (false_stereo):
# 1 channel block
# correlate shifted_0 with terms/deltas/weights/samples
if parameters.correlation_passes > 0:
assert len(shifted) == 1
correlated = correlate_channels(shifted, parameters.correlation_parameters(false_stereo), 1)
else:
correlated = shifted
else:
# 2 channel block
# correlate shifted_0/shifted_1 with terms/deltas/weights/samples
if parameters.correlation_passes > 0:
assert len(mid_side) == 2
correlated = correlate_channels(mid_side, parameters.correlation_parameters(false_stereo), 2)
else:
correlated = mid_side
# write entropy variables sub block
sub_block.reset()
write_entropy_variables(sub_block, correlated, parameters.entropy_variables)
write_sub_block(sub_blocks, WV_ENTROPY, 0, sub_block)
# write bitstream sub block
sub_block.reset()
write_bitstream(sub_block, correlated, parameters.entropy_variables)
write_sub_block(sub_blocks, WV_BITSTREAM, 0, sub_block)
# write block header with size of all sub blocks
write_block_header(
writer,
sub_blocks.bytes(),
block_index,
len(channels[0]),
context.pcmreader.bits_per_sample,
len(channels),
(len(channels) == 2) and (false_stereo == 0),
len(set([-1, -2, -3]) & set([p.term for p in parameters.correlation_parameters(false_stereo)])) > 0,
wasted,
first_block,
last_block,
magnitude,
context.pcmreader.sample_rate,
false_stereo,
crc,
)
# write sub block data to stream
sub_blocks.copy(writer)
# round-trip entropy variables
parameters.entropy_variables = [
[wv_exp2(wv_log2(p)) for p in parameters.entropy_variables[0]],
[wv_exp2(wv_log2(p)) for p in parameters.entropy_variables[1]],
]
def encode_wavpack(filename, pcmreader, block_size, correlation_passes=0, wave_header=None, wave_footer=None):
pcmreader = BufferedPCMReader(pcmreader)
output_file = open(filename, "wb")
writer = BitstreamWriter(output_file, 1)
context = EncoderContext(
pcmreader,
block_parameters(pcmreader.channels, pcmreader.channel_mask, correlation_passes),
wave_header,
wave_footer,
)
block_index = 0
# walk through PCM reader's FrameLists
frame = pcmreader.read(block_size * (pcmreader.bits_per_sample / 8) * pcmreader.channels)
while len(frame) > 0:
context.total_frames += frame.frames
context.md5sum.update(frame.to_bytes(False, pcmreader.bits_per_sample >= 16))
c = 0
for parameters in context.block_parameters:
if parameters.channel_count == 1:
channel_data = [list(frame.channel(c))]
else:
channel_data = [list(frame.channel(c)), list(frame.channel(c + 1))]
first_block = parameters is context.block_parameters[0]
last_block = parameters is context.block_parameters[-1]
context.block_offsets.append(output_file.tell())
write_block(writer, context, channel_data, block_index, first_block, last_block, parameters)
c += parameters.channel_count
block_index += frame.frames
frame = pcmreader.read(block_size * (pcmreader.bits_per_sample / 8) * pcmreader.channels)
# write MD5 sum and optional Wave footer in final block
sub_blocks = BitstreamRecorder(1)
sub_block = BitstreamRecorder(1)
sub_block.reset()
sub_block.write_bytes(context.md5sum.digest())
write_sub_block(sub_blocks, WV_MD5, 1, sub_block)
# write Wave footer in final block, if present
if context.wave_footer is not None:
sub_block.reset()
sub_block.write_bytes(context.wave_footer)
write_sub_block(sub_blocks, WV_WAVE_FOOTER, 1, sub_block)
write_block_header(
writer,
sub_blocks.bytes(),
0xFFFFFFFF,
0,
pcmreader.bits_per_sample,
1,
0,
0,
0,
1,
1,
0,
pcmreader.sample_rate,
0,
0xFFFFFFFF,
)
sub_blocks.copy(writer)
# update Wave header's "data" chunk size, if generated
if context.wave_header is None:
output_file.seek(32 + 2)
if context.wave_footer is None:
write_wave_header(writer, context.pcmreader, context.total_frames, 0)
else:
write_wave_header(writer, context.pcmreader, context.total_frames, len(context.wave_footer))
# go back and populate block headers with total samples
for block_offset in context.block_offsets:
output_file.seek(block_offset + 12, 0)
writer.write(32, block_index)
writer.close()
def encode_flac(filename,
pcmreader,
block_size=4096,
max_lpc_order=8,
min_residual_partition_order=0,
max_residual_partition_order=5,
mid_side=True,
adaptive_mid_side=False,
exhaustive_model_search=False,
disable_verbatim_subframes=False,
disable_constant_subframes=False,
disable_fixed_subframes=False,
disable_lpc_subframes=False,
padding_size=4096):
frame_sizes = []
options = Encoding_Options(block_size,
max_lpc_order,
adaptive_mid_side,
mid_side,
exhaustive_model_search,
max_residual_partition_order,
14 if pcmreader.bits_per_sample <= 16 else 30)
streaminfo = STREAMINFO(block_size,
block_size,
(2 ** 24) - 1,
0,
pcmreader.sample_rate,
pcmreader.channels,
pcmreader.bits_per_sample,
0, md5())
pcmreader = BufferedPCMReader(pcmreader)
output_file = open(filename, "wb")
writer = BitstreamWriter(output_file, False)
# write placeholder metadata blocks such as STREAMINFO and PADDING
writer.write_bytes("fLaC")
writer.build("1u 7u 24u", [0, 0, 34])
streaminfo_start = writer.getpos()
streaminfo.write(writer)
writer.build("1u 7u 24u", [1, 1, padding_size])
writer.write_bytes(b"\x00" * padding_size)
# walk through PCM reader's FrameLists
frame_number = 0
frame = pcmreader.read(block_size)
flac_frame = BitstreamRecorder(0)
while len(frame) > 0:
streaminfo.input_update(frame)
flac_frame.reset()
encode_flac_frame(flac_frame, pcmreader, options, frame_number, frame)
frame_sizes.append((flac_frame.bytes(), frame.frames))
streaminfo.output_update(flac_frame)
flac_frame.copy(writer)
frame_number += 1
frame = pcmreader.read(block_size)
# return to beginning of file and rewrite STREAMINFO block
writer.setpos(streaminfo_start)
streaminfo.write(writer)
writer.flush()
writer.close()
return frame_sizes
def encode_flac(filename,
pcmreader,
block_size=4096,
max_lpc_order=8,
min_residual_partition_order=0,
max_residual_partition_order=5,
mid_side=True,
adaptive_mid_side=False,
exhaustive_model_search=False,
disable_verbatim_subframes=False,
disable_constant_subframes=False,
disable_fixed_subframes=False,
disable_lpc_subframes=False):
current_offset = 0
frame_offsets = []
options = Encoding_Options(block_size,
max_lpc_order,
adaptive_mid_side,
mid_side,
exhaustive_model_search,
max_residual_partition_order,
14 if pcmreader.bits_per_sample <= 16 else 30)
streaminfo = STREAMINFO(block_size, block_size,
2 ** 32, 0,
pcmreader.sample_rate,
pcmreader.channels,
pcmreader.bits_per_sample,
0, md5())
pcmreader = BufferedPCMReader(pcmreader)
output_file = open(filename, "wb")
writer = BitstreamWriter(output_file, 0)
#write placeholder metadata blocks
writer.write_bytes("fLaC")
writer.build("1u 7u 24u", [1, 0, 34])
streaminfo.write(writer)
#walk through PCM reader's FrameLists
frame_number = 0
frame = pcmreader.read(block_size)
flac_frame = BitstreamRecorder(0)
while (len(frame) > 0):
frame_offsets.append((current_offset, frame.frames))
streaminfo.input_update(frame)
flac_frame.reset()
encode_flac_frame(flac_frame, pcmreader, options, frame_number, frame)
current_offset += flac_frame.bytes()
streaminfo.output_update(flac_frame)
flac_frame.copy(writer)
frame_number += 1
frame = pcmreader.read(block_size)
#return to beginning of file and rewrite STREAMINFO block
output_file.seek(8, 0)
streaminfo.write(writer)
writer.close()
return frame_offsets
