def lin2ulaw(infile, outfile, nchannels):
comp = cl.OpenCompressor(CL.G711_ULAW)
if nchannels == 1:
orig = CL.MONO
elif nchannels == 2:
orig = CL.STEREO_INTERLEAVED
# The important parameters are ORIGINAL_FORMAT and the two
# sizes. The FRAME_RATE doesn't matter in U-law, and the
# BITS_PER_COMPONENT is 16 by default.
# Notice that the COMPRESSED_BUFFER_SIZE is twice the needed
# size.
params = [CL.ORIGINAL_FORMAT, orig, \
CL.BITS_PER_COMPONENT, 16, \
CL.FRAME_RATE, 8000, \
CL.FRAME_BUFFER_SIZE, 8192, \
CL.COMPRESSED_BUFFER_SIZE, 8192]
comp.SetParams(params)
dummy = comp.Compress(0, '')
while 1:
audio = infile.read(8192)
if not audio:
break
data = comp.Compress(len(audio) / (nchannels * 2), audio)
outfile.write(data)
comp.CloseCompressor()
def compress(imgdata, width, height, bytesperpixel):
global comp
import cl
if comp is None: comp = cl.OpenCompressor(cl.JPEG)
if bytesperpixel == 1:
format = cl.GRAYSCALE
elif bytesperpixel == 4:
format = cl.RGBX
if options['forcegray']:
iformat = cl.GRAYSCALE
else:
iformat = cl.YUV
# XXX How to support 'optimize'?
params = [
cl.IMAGE_WIDTH,
width,
cl.IMAGE_HEIGHT,
height,
cl.ORIGINAL_FORMAT,
format,
cl.ORIENTATION,
cl.BOTTOM_UP,
cl.QUALITY_FACTOR,
options['quality'],
cl.INTERNAL_FORMAT,
iformat,
]
comp.SetParams(params)
jpegdata = comp.Compress(1, imgdata)
return jpegdata
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, self._sampwidth * 8, CL.FRAME_RATE, self._framerate, CL.FRAME_BUFFER_SIZE, 100, CL.COMPRESSED_BUFFER_SIZE, 100] if self._nchannels == 1: params[1] = CL.MONO elif self._nchannels == 2: params[1] = CL.STEREO_INTERLEAVED else: raise Error, 'cannot compress more than 2 channels' self._comp.SetParams(params) # the compressor produces a header which we ignore dummy = self._comp.Compress(0, '') self._convert = self._comp_data
def init_compressor(self, w, h): self.compressor = None scheme = cl.QuerySchemeFromName(cl.VIDEO, self.comp_scheme) self.compressor = cl.OpenCompressor(scheme) parambuf = [cl.IMAGE_WIDTH, w, \ cl.IMAGE_HEIGHT, h, \ cl.ORIGINAL_FORMAT, cl.YUV422DC] self.compressor.SetParams(parambuf) return self.compressor.Compress(0, '')
def _init_compression(self):
if self._comptype == 'G722':
self._convert = self._lin2adpcm
return
try:
import cl
except ImportError:
if self._comptype in ('ULAW', 'ulaw'):
try:
import audioop
self._convert = self._lin2ulaw
return
except ImportError:
pass
raise Error, 'cannot write compressed AIFF-C files'
if self._comptype in ('ULAW', 'ulaw'):
scheme = cl.G711_ULAW
elif self._comptype in ('ALAW', '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,
self._sampwidth * 8,
cl.FRAME_RATE,
self._framerate,
cl.FRAME_BUFFER_SIZE,
100,
cl.COMPRESSED_BUFFER_SIZE,
100]
if self._nchannels == 1:
params[1] = cl.MONO
elif self._nchannels == 2:
params[1] = cl.STEREO_INTERLEAVED
else:
raise Error, 'cannot compress more than 2 channels'
self._comp.SetParams(params)
dummy = self._comp.Compress(0, '')
self._convert = self._comp_data
def cjpeg(width, height, depth, image, quality): import cl, CL if depth == 3: orig = CL.RGBX elif depth == 1: orig = CL.RGB332 elif depth == 4: orig = CL.RGBA else: raise Error, 'unrecognized depth' params = [CL.ORIGINAL_FORMAT, orig, \ CL.ORIENTATION, CL.BOTTOM_UP, \ CL.IMAGE_WIDTH, width, \ CL.IMAGE_HEIGHT, height, \ CL.QUALITY_FACTOR, quality] comp = cl.OpenCompressor(CL.JPEG) comp.SetParams(params) data = comp.Compress(1, image) comp.CloseCompressor() return data
# Implement 'jpeg' interface using SGI's compression library
#! /usr/bin/env python
"""A module that reads JPEG files using the SGI Compression Library.
"""Stuff to parse AIFF-C and AIFF files.
