def encode_flac(filename, pcmreader,
block_size=4096,
max_lpc_order=8,
adaptive_mid_side=False,
mid_side=True,
exhaustive_model_search=False,
max_residual_partition_order=5):
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 *
(pcmreader.bits_per_sample / 8) *
pcmreader.channels)
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)
streaminfo.output_update(flac_frame)
flac_frame.copy(writer)
frame_number += 1
frame = pcmreader.read(block_size *
(pcmreader.bits_per_sample / 8) *
pcmreader.channels)
#return to beginning of file and rewrite STREAMINFO block
output_file.seek(8, 0)
streaminfo.write(writer)
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_shn(filename, pcmreader, is_big_endian, signed_samples, header_data, footer_data="", block_size=256):
"""filename is a string to the output file's path
pcmreader is a PCMReader object
header_data and footer_data are binary strings
block_size is the default size of each Shorten audio command
"""
pcmreader = BufferedPCMReader(pcmreader)
output_file = open(filename, "wb")
writer = BitstreamWriter(output_file, 0)
left_shift = 0
wrapped_channels = [[] for c in xrange(pcmreader.channels)]
# write magic number and version
writer.build("4b 8u", ["ajkg", 2])
bytes_written = __Counter__()
writer.add_callback(bytes_written.byte)
# write header from PCMReader info and encoding options
if pcmreader.bits_per_sample == 8:
if signed_samples:
write_long(writer, 1) # signed, 8-bit
sign_adjustment = 0
else:
write_long(writer, 2) # unsigned, 8-bit
sign_adjustment = 1 << (pcmreader.bits_per_sample - 1)
# 8-bit samples have no endianness
elif pcmreader.bits_per_sample == 16:
if signed_samples:
if is_big_endian:
write_long(writer, 3) # signed, 16-bit, big-endian
else:
write_long(writer, 5) # signed, 16-bit, little-endian
sign_adjustment = 0
else:
if is_big_endian:
write_long(writer, 4) # unsigned, 16-bit, big-endian
else:
write_long(writer, 6) # unsigned, 16-bit, little-endian
sign_adjustment = 1 << (pcmreader.bits_per_sample - 1)
else:
raise ValueError("unsupported bits_per_sample")
write_long(writer, pcmreader.channels)
write_long(writer, block_size)
write_long(writer, 0) # max LPC
write_long(writer, 0) # mean count
write_long(writer, 0) # bytes to skip
# write header as a VERBATIM block
write_unsigned(writer, COMMAND_SIZE, FN_VERBATIM)
write_unsigned(writer, VERBATIM_SIZE, len(header_data))
for b in header_data:
write_unsigned(writer, VERBATIM_BYTE_SIZE, ord(b))
# split PCMReader into block_size chunks
# and continue until the number of PCM frames is 0
frame = pcmreader.read(block_size)
while len(frame) > 0:
# if the chunk isn't block_size frames long,
# issue a command to change it
if frame.frames != block_size:
block_size = frame.frames
write_unsigned(writer, COMMAND_SIZE, FN_BLOCKSIZE)
write_long(writer, block_size)
# split chunk into individual channels
for c in xrange(pcmreader.channels):
# convert PCM data to unsigned, if necessary
if signed_samples:
channel = list(frame.channel(c))
else:
channel = [s + sign_adjustment for s in frame.channel(c)]
# if all samples are 0, issue a ZERO command
if all_zeroes(channel):
write_unsigned(writer, COMMAND_SIZE, FN_ZERO)
# wrap zeroes around for next set of channels
wrapped_channels[c] = channel
else:
# if channel's shifted bits have changed
# from the previous channel's shift
# issue a new BITSHIFT command
wasted_bits = wasted_bps(channel)
if wasted_bits != left_shift:
write_unsigned(writer, COMMAND_SIZE, FN_BITSHIFT)
write_unsigned(writer, BITSHIFT_SIZE, wasted_bits)
left_shift = wasted_bits
# and shift the channel's bits if the amount is still > 0
if left_shift > 0:
shifted = [s >> left_shift for s in channel]
else:
shifted = channel
# determine the best DIFF command and residuals
# to issue for shifted channel data
(diff, residuals) = best_diff(wrapped_channels[c], shifted)
# determine the best energy size for DIFF's residuals
energy = best_energy(residuals)
# write DIFF command, energy size and residuals
write_unsigned(writer, COMMAND_SIZE, {1: FN_DIFF1, 2: FN_DIFF2, 3: FN_DIFF3}[diff])
write_unsigned(writer, ENERGY_SIZE, energy)
for residual in residuals:
write_signed(writer, energy, residual)
# wrap shifted channels around for next set of channels
wrapped_channels[c] = shifted
# and get another set of channels to encode
frame = pcmreader.read(block_size)
# once all PCM data has been sent
# if there's any footer data, write it as another VERBATIM block
if len(footer_data) > 0:
write_unsigned(writer, COMMAND_SIZE, FN_VERBATIM)
write_unsigned(writer, VERBATIM_SIZE, len(footer_data))
for b in footer_data:
write_unsigned(writer, VERBATIM_BYTE_SIZE, ord(b))
# issue a QUIT command
write_unsigned(writer, COMMAND_SIZE, FN_QUIT)
# finally, due to Shorten's silly way of using bit buffers,
# output (not counting the 5 bytes of magic + version)
# must be padded to a multiple of 4 bytes
# or its reference decoder explodes
writer.byte_align()
while (int(bytes_written) % 4) != 0:
writer.write(8, 0)
def encode_shn(filename,
pcmreader,
is_big_endian,
signed_samples,
header_data,
footer_data="",
block_size=256):
"""filename is a string to the output file's path
pcmreader is a PCMReader object
header_data and footer_data are binary strings
block_size is the default size of each Shorten audio command
"""
pcmreader = BufferedPCMReader(pcmreader)
output_file = open(filename, "wb")
writer = BitstreamWriter(output_file, 0)
left_shift = 0
wrapped_channels = [[] for c in xrange(pcmreader.channels)]
#write magic number and version
writer.build("4b 8u", ["ajkg", 2])
bytes_written = __Counter__()
writer.add_callback(bytes_written.byte)
#write header from PCMReader info and encoding options
if (pcmreader.bits_per_sample == 8):
if (signed_samples):
write_long(writer, 1) # signed, 8-bit
sign_adjustment = 0
else:
write_long(writer, 2) # unsigned, 8-bit
sign_adjustment = 1 << (pcmreader.bits_per_sample - 1)
#8-bit samples have no endianness
elif (pcmreader.bits_per_sample == 16):
if (signed_samples):
if (is_big_endian):
write_long(writer, 3) # signed, 16-bit, big-endian
else:
write_long(writer, 5) # signed, 16-bit, little-endian
sign_adjustment = 0
else:
if (is_big_endian):
write_long(writer, 4) # unsigned, 16-bit, big-endian
else:
write_long(writer, 6) # unsigned, 16-bit, little-endian
sign_adjustment = 1 << (pcmreader.bits_per_sample - 1)
else:
raise ValueError("unsupported bits_per_sample")
write_long(writer, pcmreader.channels)
write_long(writer, block_size)
write_long(writer, 0) # max LPC
write_long(writer, 0) # mean count
write_long(writer, 0) # bytes to skip
#write header as a VERBATIM block
write_unsigned(writer, COMMAND_SIZE, FN_VERBATIM)
write_unsigned(writer, VERBATIM_SIZE, len(header_data))
for b in header_data:
write_unsigned(writer, VERBATIM_BYTE_SIZE, ord(b))
#split PCMReader into block_size chunks
#and continue until the number of PCM frames is 0
frame = pcmreader.read(block_size)
while (len(frame) > 0):
#if the chunk isn't block_size frames long,
#issue a command to change it
if (frame.frames != block_size):
block_size = frame.frames
write_unsigned(writer, COMMAND_SIZE, FN_BLOCKSIZE)
write_long(writer, block_size)
#split chunk into individual channels
for c in xrange(pcmreader.channels):
#convert PCM data to unsigned, if necessary
if (signed_samples):
channel = list(frame.channel(c))
else:
channel = [s + sign_adjustment for s in frame.channel(c)]
#if all samples are 0, issue a ZERO command
if (all_zeroes(channel)):
write_unsigned(writer, COMMAND_SIZE, FN_ZERO)
#wrap zeroes around for next set of channels
wrapped_channels[c] = channel
else:
#if channel's shifted bits have changed
#from the previous channel's shift
#issue a new BITSHIFT command
wasted_bits = wasted_bps(channel)
if (wasted_bits != left_shift):
write_unsigned(writer, COMMAND_SIZE, FN_BITSHIFT)
write_unsigned(writer, BITSHIFT_SIZE, wasted_bits)
left_shift = wasted_bits
#and shift the channel's bits if the amount is still > 0
if (left_shift > 0):
shifted = [s >> left_shift for s in channel]
else:
shifted = channel
#determine the best DIFF command and residuals
#to issue for shifted channel data
(diff, residuals) = best_diff(wrapped_channels[c], shifted)
#determine the best energy size for DIFF's residuals
energy = best_energy(residuals)
#write DIFF command, energy size and residuals
write_unsigned(writer, COMMAND_SIZE, {
1: FN_DIFF1,
2: FN_DIFF2,
3: FN_DIFF3
}[diff])
write_unsigned(writer, ENERGY_SIZE, energy)
for residual in residuals:
write_signed(writer, energy, residual)
#wrap shifted channels around for next set of channels
wrapped_channels[c] = shifted
#and get another set of channels to encode
frame = pcmreader.read(block_size)
#once all PCM data has been sent
#if there's any footer data, write it as another VERBATIM block
if (len(footer_data) > 0):
write_unsigned(writer, COMMAND_SIZE, FN_VERBATIM)
write_unsigned(writer, VERBATIM_SIZE, len(footer_data))
for b in footer_data:
write_unsigned(writer, VERBATIM_BYTE_SIZE, ord(b))
#issue a QUIT command
write_unsigned(writer, COMMAND_SIZE, FN_QUIT)
#finally, due to Shorten's silly way of using bit buffers,
#output (not counting the 5 bytes of magic + version)
#must be padded to a multiple of 4 bytes
#or its reference decoder explodes
writer.byte_align()
while ((int(bytes_written) % 4) != 0):
writer.write(8, 0)
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
