class AiffReader(object):
"""a PCMReader object for reading AIFF file contents"""
def __init__(self, aiff_filename):
"""aiff_filename is a string"""
from audiotools.bitstream import BitstreamReader
self.stream = BitstreamReader(open(aiff_filename, "rb"), False)
# ensure FORM<size>AIFF header is ok
try:
(form, total_size, aiff) = self.stream.parse("4b 32u 4b")
except struct.error:
from audiotools.text import ERR_AIFF_INVALID_AIFF
raise InvalidAIFF(ERR_AIFF_INVALID_AIFF)
if (form != b'FORM'):
from audiotools.text import ERR_AIFF_NOT_AIFF
raise ValueError(ERR_AIFF_NOT_AIFF)
elif (aiff != b'AIFF'):
from audiotools.text import ERR_AIFF_INVALID_AIFF
raise ValueError(ERR_AIFF_INVALID_AIFF)
else:
total_size -= 4
comm_chunk_read = False
# walk through chunks until "SSND" chunk encountered
while (total_size > 0):
try:
(chunk_id, chunk_size) = self.stream.parse("4b 32u")
except struct.error:
from audiotools.text import ERR_AIFF_INVALID_AIFF
raise ValueError(ERR_AIFF_INVALID_AIFF)
if (not frozenset(chunk_id).issubset(AiffAudio.PRINTABLE_ASCII)):
from audiotools.text import ERR_AIFF_INVALID_CHUNK_ID
raise ValueError(ERR_AIFF_INVALID_CHUNK_ID)
else:
total_size -= 8
if (chunk_id == b"COMM"):
# when "COMM" chunk encountered,
# use it to populate PCMReader attributes
(self.channels, self.total_pcm_frames, self.bits_per_sample,
self.sample_rate, channel_mask) = parse_comm(self.stream)
self.channel_mask = int(channel_mask)
self.bytes_per_pcm_frame = ((self.bits_per_sample // 8) *
self.channels)
self.remaining_pcm_frames = self.total_pcm_frames
comm_chunk_read = True
elif (chunk_id == b"SSND"):
# when "SSND" chunk encountered,
# strip off the "offset" and "block_size" attributes
# and ready PCMReader for reading
if (not comm_chunk_read):
from audiotools.text import ERR_AIFF_PREMATURE_SSND_CHUNK
raise ValueError(ERR_AIFF_PREMATURE_SSND_CHUNK)
else:
self.stream.skip_bytes(8)
self.stream.mark()
return
else:
# all other chunks are ignored
self.stream.skip_bytes(chunk_size)
if (chunk_size % 2):
if (len(self.stream.read_bytes(1)) < 1):
from audiotools.text import ERR_AIFF_INVALID_CHUNK
raise ValueError(ERR_AIFF_INVALID_CHUNK)
total_size -= (chunk_size + 1)
else:
total_size -= chunk_size
else:
# raise an error if no "SSND" chunk is encountered
from audiotools.text import ERR_AIFF_NO_SSND_CHUNK
raise ValueError(ERR_AIFF_NO_SSND_CHUNK)
def __enter__(self):
return self
def __exit__(self, exc_type, exc_value, traceback):
self.close()
def __del__(self):
if (self.stream.has_mark()):
self.stream.unmark()
def read(self, pcm_frames):
"""try to read a pcm.FrameList with the given number of PCM frames"""
# try to read requested PCM frames or remaining frames
requested_pcm_frames = min(max(pcm_frames, 1),
self.remaining_pcm_frames)
requested_bytes = (self.bytes_per_pcm_frame * requested_pcm_frames)
pcm_data = self.stream.read_bytes(requested_bytes)
# raise exception if "SSND" chunk exhausted early
if (len(pcm_data) < requested_bytes):
from audiotools.text import ERR_AIFF_TRUNCATED_SSND_CHUNK
raise IOError(ERR_AIFF_TRUNCATED_SSND_CHUNK)
else:
self.remaining_pcm_frames -= requested_pcm_frames
# return parsed chunk
return FrameList(pcm_data, self.channels, self.bits_per_sample,
True, True)
def read_closed(self, pcm_frames):
raise ValueError("cannot read closed stream")
def seek(self, pcm_frame_offset):
"""tries to seek to the given PCM frame offset
returns the total amount of frames actually seeked over"""
if (pcm_frame_offset < 0):
from audiotools.text import ERR_NEGATIVE_SEEK
raise ValueError(ERR_NEGATIVE_SEEK)
# ensure one doesn't walk off the end of the file
pcm_frame_offset = min(pcm_frame_offset, self.total_pcm_frames)
# position file in "SSND" chunk
self.stream.rewind()
self.stream.seek((pcm_frame_offset * self.bytes_per_pcm_frame), 1)
self.remaining_pcm_frames = (self.total_pcm_frames - pcm_frame_offset)
return pcm_frame_offset
def seek_closed(self, pcm_frame_offset):
raise ValueError("cannot seek closed stream")
def close(self):
"""closes the stream for reading"""
self.stream.close()
self.read = self.read_closed
self.seek = self.seek_closed
class AiffReader(object):
"""a PCMReader object for reading AIFF file contents"""
def __init__(self, aiff_filename):
"""aiff_filename is a string"""
from audiotools.bitstream import BitstreamReader
self.stream = BitstreamReader(open(aiff_filename, "rb"), False)
# ensure FORM<size>AIFF header is ok
try:
(form,
total_size,
aiff) = self.stream.parse("4b 32u 4b")
except struct.error:
from audiotools.text import ERR_AIFF_INVALID_AIFF
raise InvalidAIFF(ERR_AIFF_INVALID_AIFF)
if (form != b'FORM'):
from audiotools.text import ERR_AIFF_NOT_AIFF
raise ValueError(ERR_AIFF_NOT_AIFF)
elif (aiff != b'AIFF'):
from audiotools.text import ERR_AIFF_INVALID_AIFF
raise ValueError(ERR_AIFF_INVALID_AIFF)
else:
total_size -= 4
comm_chunk_read = False
# walk through chunks until "SSND" chunk encountered
while (total_size > 0):
try:
(chunk_id,
chunk_size) = self.stream.parse("4b 32u")
except struct.error:
from audiotools.text import ERR_AIFF_INVALID_AIFF
raise ValueError(ERR_AIFF_INVALID_AIFF)
if (not frozenset(chunk_id).issubset(AiffAudio.PRINTABLE_ASCII)):
from audiotools.text import ERR_AIFF_INVALID_CHUNK_ID
raise ValueError(ERR_AIFF_INVALID_CHUNK_ID)
else:
total_size -= 8
if (chunk_id == b"COMM"):
# when "COMM" chunk encountered,
# use it to populate PCMReader attributes
(self.channels,
self.total_pcm_frames,
self.bits_per_sample,
self.sample_rate,
channel_mask) = parse_comm(self.stream)
self.channel_mask = int(channel_mask)
self.bytes_per_pcm_frame = ((self.bits_per_sample // 8) *
self.channels)
self.remaining_pcm_frames = self.total_pcm_frames
comm_chunk_read = True
elif (chunk_id == b"SSND"):
# when "SSND" chunk encountered,
# strip off the "offset" and "block_size" attributes
# and ready PCMReader for reading
if (not comm_chunk_read):
from audiotools.text import ERR_AIFF_PREMATURE_SSND_CHUNK
raise ValueError(ERR_AIFF_PREMATURE_SSND_CHUNK)
else:
self.stream.skip_bytes(8)
self.stream.mark()
return
else:
# all other chunks are ignored
self.stream.skip_bytes(chunk_size)
if (chunk_size % 2):
if (len(self.stream.read_bytes(1)) < 1):
from audiotools.text import ERR_AIFF_INVALID_CHUNK
raise ValueError(ERR_AIFF_INVALID_CHUNK)
total_size -= (chunk_size + 1)
else:
total_size -= chunk_size
else:
# raise an error if no "SSND" chunk is encountered
from audiotools.text import ERR_AIFF_NO_SSND_CHUNK
raise ValueError(ERR_AIFF_NO_SSND_CHUNK)
def __enter__(self):
return self
def __exit__(self, exc_type, exc_value, traceback):
self.close()
def __del__(self):
if (self.stream.has_mark()):
self.stream.unmark()
def read(self, pcm_frames):
"""try to read a pcm.FrameList with the given number of PCM frames"""
# try to read requested PCM frames or remaining frames
requested_pcm_frames = min(max(pcm_frames, 1),
self.remaining_pcm_frames)
requested_bytes = (self.bytes_per_pcm_frame *
requested_pcm_frames)
pcm_data = self.stream.read_bytes(requested_bytes)
# raise exception if "SSND" chunk exhausted early
if (len(pcm_data) < requested_bytes):
from audiotools.text import ERR_AIFF_TRUNCATED_SSND_CHUNK
raise IOError(ERR_AIFF_TRUNCATED_SSND_CHUNK)
else:
self.remaining_pcm_frames -= requested_pcm_frames
# return parsed chunk
return FrameList(pcm_data,
self.channels,
self.bits_per_sample,
True,
True)
def read_closed(self, pcm_frames):
raise ValueError("cannot read closed stream")
def seek(self, pcm_frame_offset):
"""tries to seek to the given PCM frame offset
returns the total amount of frames actually seeked over"""
if (pcm_frame_offset < 0):
from audiotools.text import ERR_NEGATIVE_SEEK
raise ValueError(ERR_NEGATIVE_SEEK)
# ensure one doesn't walk off the end of the file
pcm_frame_offset = min(pcm_frame_offset,
self.total_pcm_frames)
# position file in "SSND" chunk
self.stream.rewind()
self.stream.seek((pcm_frame_offset * self.bytes_per_pcm_frame), 1)
self.remaining_pcm_frames = (self.total_pcm_frames -
pcm_frame_offset)
return pcm_frame_offset
def seek_closed(self, pcm_frame_offset):
raise ValueError("cannot seek closed stream")
def close(self):
"""closes the stream for reading"""
self.stream.close()
self.read = self.read_closed
self.seek = self.seek_closed
class WaveReader(object):
"""a PCMReader object for reading wave file contents"""
def __init__(self, wave_filename):
"""wave_filename is a string"""
from audiotools.bitstream import BitstreamReader
self.stream = BitstreamReader(open(wave_filename, "rb"), True)
# ensure RIFF<size>WAVE header is ok
try:
(riff, total_size, wave) = self.stream.parse("4b 32u 4b")
except struct.error:
from audiotools.text import ERR_WAV_INVALID_WAVE
self.stream.close()
raise ValueError(ERR_WAV_INVALID_WAVE)
if (riff != b'RIFF'):
from audiotools.text import ERR_WAV_NOT_WAVE
self.stream.close()
raise ValueError(ERR_WAV_NOT_WAVE)
elif (wave != b'WAVE'):
from audiotools.text import ERR_WAV_INVALID_WAVE
self.stream.close()
raise ValueError(ERR_WAV_INVALID_WAVE)
else:
total_size -= 4
fmt_chunk_read = False
# walk through chunks until "data" chunk encountered
while (total_size > 0):
try:
(chunk_id, chunk_size) = self.stream.parse("4b 32u")
except struct.error:
from audiotools.text import ERR_WAV_INVALID_WAVE
self.stream.close()
raise ValueError(ERR_WAV_INVALID_WAVE)
if (not frozenset(chunk_id).issubset(WaveAudio.PRINTABLE_ASCII)):
from audiotools.text import ERR_WAV_INVALID_CHUNK
self.stream.close()
raise ValueError(ERR_WAV_INVALID_CHUNK)
else:
total_size -= 8
if (chunk_id == b"fmt "):
# when "fmt " chunk encountered,
# use it to populate PCMReader attributes
(self.channels, self.sample_rate, self.bits_per_sample,
channel_mask) = parse_fmt(self.stream)
self.channel_mask = int(channel_mask)
self.bytes_per_pcm_frame = ((self.bits_per_sample // 8) *
self.channels)
fmt_chunk_read = True
elif (chunk_id == b"data"):
# when "data" chunk encountered,
# use its size to determine total PCM frames
# and ready PCMReader for reading
if (not fmt_chunk_read):
from audiotools.text import ERR_WAV_PREMATURE_DATA
self.stream.close()
raise ValueError(ERR_WAV_PREMATURE_DATA)
else:
self.total_pcm_frames = (chunk_size //
self.bytes_per_pcm_frame)
self.remaining_pcm_frames = self.total_pcm_frames
self.stream.mark()
return
else:
# all other chunks are ignored
self.stream.skip_bytes(chunk_size)
if (chunk_size % 2):
if (len(self.stream.read_bytes(1)) < 1):
from audiotools.text import ERR_WAV_INVALID_CHUNK
self.stream.close()
raise ValueError(ERR_WAV_INVALID_CHUNK)
total_size -= (chunk_size + 1)
else:
total_size -= chunk_size
else:
# raise an error if no "data" chunk is encountered
from audiotools.text import ERR_WAV_NO_DATA_CHUNK
self.stream.close()
raise ValueError(ERR_WAV_NO_DATA_CHUNK)
def __enter__(self):
return self
def __exit__(self, exc_type, exc_value, traceback):
self.close()
def __del__(self):
if (self.stream.has_mark()):
self.stream.unmark()
def read(self, pcm_frames):
"""try to read a pcm.FrameList with the given number of PCM frames"""
# try to read requested PCM frames or remaining frames
requested_pcm_frames = min(max(pcm_frames, 1),
self.remaining_pcm_frames)
requested_bytes = (self.bytes_per_pcm_frame * requested_pcm_frames)
pcm_data = self.stream.read_bytes(requested_bytes)
# raise exception if "data" chunk exhausted early
if (len(pcm_data) < requested_bytes):
from audiotools.text import ERR_WAV_TRUNCATED_DATA_CHUNK
raise IOError(ERR_WAV_TRUNCATED_DATA_CHUNK)
else:
self.remaining_pcm_frames -= requested_pcm_frames
# return parsed chunk
return FrameList(pcm_data, self.channels, self.bits_per_sample,
False, self.bits_per_sample != 8)
def read_closed(self, pcm_frames):
raise ValueError("cannot read closed stream")
def seek(self, pcm_frame_offset):
"""tries to seek to the given PCM frame offset
returns the total amount of frames actually seeked over"""
if (pcm_frame_offset < 0):
from audiotools.text import ERR_NEGATIVE_SEEK
raise ValueError(ERR_NEGATIVE_SEEK)
# ensure one doesn't walk off the end of the file
pcm_frame_offset = min(pcm_frame_offset, self.total_pcm_frames)
# position file in "data" chunk
self.stream.rewind()
self.stream.seek(pcm_frame_offset * self.bytes_per_pcm_frame, 1)
self.remaining_pcm_frames = (self.total_pcm_frames - pcm_frame_offset)
return pcm_frame_offset
def seek_closed(self, pcm_frame_offset):
raise ValueError("cannot seek closed stream")
def close(self):
"""closes the stream for reading"""
self.stream.close()
self.read = self.read_closed
self.seek = self.seek_closed
class WaveReader(object):
"""a PCMReader object for reading wave file contents"""
def __init__(self, wave_filename):
"""wave_filename is a string"""
from audiotools.bitstream import BitstreamReader
self.stream = BitstreamReader(open(wave_filename, "rb"), True)
# ensure RIFF<size>WAVE header is ok
try:
(riff,
total_size,
wave) = self.stream.parse("4b 32u 4b")
except struct.error:
from audiotools.text import ERR_WAV_INVALID_WAVE
self.stream.close()
raise ValueError(ERR_WAV_INVALID_WAVE)
if (riff != b'RIFF'):
from audiotools.text import ERR_WAV_NOT_WAVE
self.stream.close()
raise ValueError(ERR_WAV_NOT_WAVE)
elif (wave != b'WAVE'):
from audiotools.text import ERR_WAV_INVALID_WAVE
self.stream.close()
raise ValueError(ERR_WAV_INVALID_WAVE)
else:
total_size -= 4
fmt_chunk_read = False
# walk through chunks until "data" chunk encountered
while (total_size > 0):
try:
(chunk_id,
chunk_size) = self.stream.parse("4b 32u")
except struct.error:
from audiotools.text import ERR_WAV_INVALID_WAVE
self.stream.close()
raise ValueError(ERR_WAV_INVALID_WAVE)
if (not frozenset(chunk_id).issubset(WaveAudio.PRINTABLE_ASCII)):
from audiotools.text import ERR_WAV_INVALID_CHUNK
self.stream.close()
raise ValueError(ERR_WAV_INVALID_CHUNK)
else:
total_size -= 8
if (chunk_id == b"fmt "):
# when "fmt " chunk encountered,
# use it to populate PCMReader attributes
(self.channels,
self.sample_rate,
self.bits_per_sample,
channel_mask) = parse_fmt(self.stream)
self.channel_mask = int(channel_mask)
self.bytes_per_pcm_frame = ((self.bits_per_sample // 8) *
self.channels)
fmt_chunk_read = True
elif (chunk_id == b"data"):
# when "data" chunk encountered,
# use its size to determine total PCM frames
# and ready PCMReader for reading
if (not fmt_chunk_read):
from audiotools.text import ERR_WAV_PREMATURE_DATA
self.stream.close()
raise ValueError(ERR_WAV_PREMATURE_DATA)
else:
self.total_pcm_frames = (chunk_size //
self.bytes_per_pcm_frame)
self.remaining_pcm_frames = self.total_pcm_frames
self.stream.mark()
return
else:
# all other chunks are ignored
self.stream.skip_bytes(chunk_size)
if (chunk_size % 2):
if (len(self.stream.read_bytes(1)) < 1):
from audiotools.text import ERR_WAV_INVALID_CHUNK
self.stream.close()
raise ValueError(ERR_WAV_INVALID_CHUNK)
total_size -= (chunk_size + 1)
else:
total_size -= chunk_size
else:
# raise an error if no "data" chunk is encountered
from audiotools.text import ERR_WAV_NO_DATA_CHUNK
self.stream.close()
raise ValueError(ERR_WAV_NO_DATA_CHUNK)
def __enter__(self):
return self
def __exit__(self, exc_type, exc_value, traceback):
self.close()
def __del__(self):
if (self.stream.has_mark()):
self.stream.unmark()
def read(self, pcm_frames):
"""try to read a pcm.FrameList with the given number of PCM frames"""
# try to read requested PCM frames or remaining frames
requested_pcm_frames = min(max(pcm_frames, 1),
self.remaining_pcm_frames)
requested_bytes = (self.bytes_per_pcm_frame *
requested_pcm_frames)
pcm_data = self.stream.read_bytes(requested_bytes)
# raise exception if "data" chunk exhausted early
if (len(pcm_data) < requested_bytes):
from audiotools.text import ERR_WAV_TRUNCATED_DATA_CHUNK
raise IOError(ERR_WAV_TRUNCATED_DATA_CHUNK)
else:
self.remaining_pcm_frames -= requested_pcm_frames
# return parsed chunk
return FrameList(pcm_data,
self.channels,
self.bits_per_sample,
False,
self.bits_per_sample != 8)
def read_closed(self, pcm_frames):
raise ValueError("cannot read closed stream")
def seek(self, pcm_frame_offset):
"""tries to seek to the given PCM frame offset
returns the total amount of frames actually seeked over"""
if (pcm_frame_offset < 0):
from audiotools.text import ERR_NEGATIVE_SEEK
raise ValueError(ERR_NEGATIVE_SEEK)
# ensure one doesn't walk off the end of the file
pcm_frame_offset = min(pcm_frame_offset, self.total_pcm_frames)
# position file in "data" chunk
self.stream.rewind()
self.stream.seek(pcm_frame_offset * self.bytes_per_pcm_frame, 1)
self.remaining_pcm_frames = (self.total_pcm_frames -
pcm_frame_offset)
return pcm_frame_offset
def seek_closed(self, pcm_frame_offset):
raise ValueError("cannot seek closed stream")
def close(self):
"""closes the stream for reading"""
self.stream.close()
self.read = self.read_closed
self.seek = self.seek_closed
