aifc.py: added missing tell() method in AIFC write class;
use audioop module as backup for cl module when reading or
writing u-law compressed files.
sunau.py: interface with the same methods as aifc for Sun and NeXT
audio files
diff --git a/Lib/aifc.py b/Lib/aifc.py
index 2d897be..ee1f8f0 100644
--- a/Lib/aifc.py
+++ b/Lib/aifc.py
@@ -40,7 +40,7 @@
# <size of the samples> (2 bytes)
# <sampling frequency> (10 bytes, IEEE 80-bit extended
# floating point)
-# if AIFF-C files only:
+# in AIFF-C files only:
# <compression type> (4 bytes)
# <human-readable version of compression type> ("pstring")
# SSND
@@ -58,9 +58,9 @@
# or
# f = aifc.openfp(filep, 'r')
# where file is the name of a file and filep is an open file pointer.
-# The open file pointer must have methods read(), seek(), and
-# close(). In some types of audio files, if the setpos() method is
-# not used, the seek() method is not necessary.
+# The open file pointer must have methods read(), seek(), and close().
+# In some types of audio files, if the setpos() method is not used,
+# the seek() method is not necessary.
#
# This returns an instance of a class with the following public methods:
# getnchannels() -- returns number of audio channels (1 for
@@ -85,6 +85,8 @@
# The position returned by tell(), the position given to setpos() and
# the position of marks are all compatible and have nothing to do with
# the actual postion in the file.
+# The close() method is called automatically when the class instance
+# is destroyed.
#
# Writing AIFF files:
# f = aifc.open(file, 'w')
@@ -122,11 +124,13 @@
# but when it is set to the correct value, the header does not have to
# be patched up.
# It is best to first set all parameters, perhaps possibly the
-# compression type, and the write audio frames using writeframesraw.
+# compression type, and then write audio frames using writeframesraw.
# When all frames have been written, either call writeframes('') or
# close() to patch up the sizes in the header.
# Marks can be added anytime. If there are any marks, ypu must call
# close() after all frames have been written.
+# The close() method is called automatically when the class instance
+# is destroyed.
#
# When a file is opened with the extension '.aiff', an AIFF file is
# written, otherwise an AIFF-C file is written. This default can be
@@ -347,7 +351,7 @@
# methods
# _soundpos -- the position in the audio stream
# available through the tell() method, set through the
- # tell() method
+ # setpos() method
#
# These variables are used internally only:
# _version -- the AIFF-C version number
@@ -362,6 +366,7 @@
self._file = file
self._version = 0
self._decomp = None
+ self._convert = None
self._markers = []
self._soundpos = 0
form = self._file.read(4)
@@ -433,6 +438,10 @@
def init(self, filename):
return self.initfp(builtin.open(filename, 'r'))
+ def __del__(self):
+ if self._file:
+ self.close()
+
#
# User visible methods.
#
@@ -475,8 +484,9 @@
## return self._version
def getparams(self):
- return self._nchannels, self._sampwidth, self._framerate, \
- self._nframes, self._comptype, self._compname
+ return self.getnchannels(), self.getsampwidth(), \
+ self.getframerate(), self.getnframes(), \
+ self.getcomptype(), self.getcompname()
def getmarkers(self):
if len(self._markers) == 0:
@@ -506,16 +516,24 @@
if nframes == 0:
return ''
data = self._ssnd_chunk.read(nframes * self._framesize)
- if self._decomp and data:
- dummy = self._decomp.SetParam(CL.FRAME_BUFFER_SIZE, \
- len(data) * 2)
- data = self._decomp.Decompress(len(data) / self._nchannels, data)
+ if self._convert and data:
+ data = self._convert(data)
self._soundpos = self._soundpos + len(data) / (self._nchannels * self._sampwidth)
return data
#
# Internal methods.
#
+ def _decomp_data(self, data):
+ dummy = self._decomp.SetParam(CL.FRAME_BUFFER_SIZE,
+ len(data) * 2)
+ return self._decomp.Decompress(len(data) / self._nchannels,
+ data)
+
+ def _ulaw2lin(self, data):
+ import audioop
+ return audioop.ulaw2lin(data, 2)
+
def _read_comm_chunk(self, chunk):
nchannels = _read_short(chunk)
self._nchannels = _convert1(nchannels, _nchannelslist)
@@ -547,6 +565,14 @@
try:
import cl, CL
except ImportError:
+ if self._comptype == 'ULAW':
+ try:
+ import audioop
+ self._convert = self._ulaw2lin
+ self._framesize = self._framesize / 2
+ return
+ except ImportError:
+ pass
raise Error, 'cannot read compressed AIFF-C files'
if self._comptype == 'ULAW':
scheme = CL.G711_ULAW
@@ -557,6 +583,7 @@
else:
raise Error, 'unsupported compression type'
self._decomp = cl.OpenDecompressor(scheme)
+ self._convert = self._decomp_data
else:
self._comptype = 'NONE'
self._compname = 'not compressed'
@@ -622,6 +649,7 @@
self._comptype = 'NONE'
self._compname = 'not compressed'
self._comp = None
+ self._convert = None
self._nchannels = 0
self._sampwidth = 0
self._framerate = 0
@@ -634,6 +662,10 @@
self._aifc = 1 # AIFF-C is default
return self
+ def __del__(self):
+ if self._file:
+ self.close()
+
#
# User visible methods.
#
@@ -752,15 +784,14 @@
return None
return self._markers
+ def tell(self):
+ return self._nframeswritten
+
def writeframesraw(self, data):
self._ensure_header_written(len(data))
nframes = len(data) / (self._sampwidth * self._nchannels)
- if self._comp:
- dummy = self._comp.SetParam(CL.FRAME_BUFFER_SIZE, \
- len(data))
- dummy = self._comp.SetParam(CL.COMPRESSED_BUFFER_SIZE,\
- len(data))
- data = self._comp.Compress(nframes, data)
+ if self._convert:
+ data = self._convert(data)
self._file.write(data)
self._nframeswritten = self._nframeswritten + nframes
self._datawritten = self._datawritten + len(data)
@@ -791,6 +822,15 @@
#
# Internal methods.
#
+ def _comp_data(self, data):
+ dum = self._comp.SetParam(CL.FRAME_BUFFER_SIZE, len(data))
+ dum = self._comp.SetParam(CL.COMPRESSED_BUFFER_SIZE, len(data))
+ return self._comp.Compress(nframes, data)
+
+ def _lin2ulaw(self, data):
+ import audioop
+ return audioop.lin2ulaw(data, 2)
+
def _ensure_header_written(self, datasize):
if not self._nframeswritten:
if self._comptype in ('ULAW', 'ALAW'):
@@ -806,37 +846,48 @@
raise Error, 'sampling rate not specified'
self._write_header(datasize)
+ def _init_compression(self):
+ try:
+ import cl, CL
+ except ImportError:
+ if self._comptype == 'ULAW':
+ try:
+ import audioop
+ self._convert = self._lin2ulaw
+ return
+ except ImportError:
+ pass
+ raise Error, 'cannot write compressed AIFF-C files'
+ if self._comptype == 'ULAW':
+ scheme = CL.G711_ULAW
+ elif self._comptype == 'ALAW':
+ scheme = CL.G711_ALAW
+ else:
+ raise Error, 'unsupported compression type'
+ self._comp = cl.OpenCompressor(scheme)
+ params = [CL.ORIGINAL_FORMAT, 0, \
+ CL.BITS_PER_COMPONENT, 0, \
+ CL.FRAME_RATE, self._framerate, \
+ CL.FRAME_BUFFER_SIZE, 100, \
+ CL.COMPRESSED_BUFFER_SIZE, 100]
+ if self._nchannels == AL.MONO:
+ params[1] = CL.MONO
+ else:
+ params[1] = CL.STEREO_INTERLEAVED
+ if self._sampwidth == AL.SAMPLE_8:
+ params[3] = 8
+ elif self._sampwidth == AL.SAMPLE_16:
+ params[3] = 16
+ else:
+ params[3] = 24
+ self._comp.SetParams(params)
+ # the compressor produces a header which we ignore
+ dummy = self._comp.Compress(0, '')
+ self._convert = self._comp_data
+
def _write_header(self, initlength):
if self._aifc and self._comptype != 'NONE':
- try:
- import cl, CL
- except ImportError:
- raise Error, 'cannot write compressed AIFF-C files'
- if self._comptype == 'ULAW':
- scheme = CL.G711_ULAW
- elif self._comptype == 'ALAW':
- scheme = CL.G711_ALAW
- else:
- raise Error, 'unsupported compression type'
- self._comp = cl.OpenCompressor(scheme)
- params = [CL.ORIGINAL_FORMAT, 0, \
- CL.BITS_PER_COMPONENT, 0, \
- CL.FRAME_RATE, self._framerate, \
- CL.FRAME_BUFFER_SIZE, 100, \
- CL.COMPRESSED_BUFFER_SIZE, 100]
- if self._nchannels == AL.MONO:
- params[1] = CL.MONO
- else:
- params[1] = CL.STEREO_INTERLEAVED
- if self._sampwidth == AL.SAMPLE_8:
- params[3] = 8
- elif self._sampwidth == AL.SAMPLE_16:
- params[3] = 16
- else:
- params[3] = 24
- self._comp.SetParams(params)
- # the compressor produces a header which we ignore
- dummy = self._comp.Compress(0, '')
+ self._init_compression()
self._file.write('FORM')
if not self._nframes:
self._nframes = initlength / (self._nchannels * self._sampwidth)