[Bug 958487] Re: small python program to list portaudio machines crashed

[Matthias Klose]

why is this an issue with the ctypes module?


** Visibility changed to: Public

** Package changed: python2.7 (Ubuntu) => ubuntu

** Changed in: ubuntu
       Status: New => Incomplete

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Title:
  small python program to list portaudio machines crashed

Status in Ubuntu:
  Incomplete

Bug description:
  #! /usr/bin/python

  # Test for PortAudio devices using ctypes

  import ctypes, ctypes.util

  class PaDeviceInfo (ctypes.Structure):
    _fields_ = [
  	('structVersion', ctypes.c_int),
  	('name', ctypes.c_char_p),
  	('hostApi', ctypes.c_int),							# PaHostApiIndex
  	('maxInputChannels', ctypes.c_int),
  	('maxOutputChannels', ctypes.c_int),
  	('defaultLowInputLatency', ctypes.c_double),		# PaTime
  	('defaultLowOutputLatency', ctypes.c_double),		# PaTime
  	('defaultHighInputLatency', ctypes.c_double),		# PaTime
  	('defaultHighOutputLatency', ctypes.c_double),		# PaTime
  	('defaultSampleRate', ctypes.c_double),
  	]

  class PaHostApiInfo (ctypes.Structure):
    _fields_ = [
  	('structVersion', ctypes.c_int),
  	('type', ctypes.c_int),			# enum PaHostApiTypeId
  	('name', ctypes.c_char_p),
  	('deviceCount', ctypes.c_int),
  	('defaultInputDevice', ctypes.c_int),
  	('defaultOutputDevice', ctypes.c_int),
  	]

  class PaStreamParameters (ctypes.Structure):
    _fields_ = [
  	('device', ctypes.c_int),						#PaDeviceIndex
  	('channelCount', ctypes.c_int),
  	('sampleFormat', ctypes.c_ulong),				#PaSampleFormat
  	('suggestedLatency', ctypes.c_double),			# PaTime
  	('hostApiSpecificStreamInfo', ctypes.c_void_p),
  	]

  pa_name = ctypes.util.find_library("portaudio")
  pa = ctypes.CDLL(pa_name)

  pa.Pa_GetDeviceInfo.restype		= ctypes.POINTER(PaDeviceInfo)
  pa.Pa_GetHostApiInfo.restype	= ctypes.POINTER(PaHostApiInfo)
  pa.Pa_GetVersionText.restype	= ctypes.c_char_p

  inputParameters = PaStreamParameters (device=0, channelCount=2,
  			sampleFormat=2, suggestedLatency=0,		# format 2 is paInt32
  			hostApiSpecificStreamInfo=ctypes.c_void_p() )

  outputParameters =  PaStreamParameters (device=0, channelCount=2,
  			sampleFormat=2, suggestedLatency=0,		# format 2 is paInt32
  			hostApiSpecificStreamInfo=ctypes.c_void_p() )

  print 'Open', pa.Pa_Initialize()
  try:
    print 'Version', pa.Pa_GetVersion()
    print 'Version Text', pa.Pa_GetVersionText()
    count = pa.Pa_GetDeviceCount()
    print 'NumDev', count
    for i in range(count):
      pt_info = pa.Pa_GetDeviceInfo(i)
      info = pt_info.contents
      print "Device %2d, host api %s" % (i, pa.Pa_GetHostApiInfo(info.hostApi).contents.name)
      print "    Name %s" %  info.name
      print "    Max inputs %d,  Max outputs %d" % (info.maxInputChannels, info.maxOutputChannels)
      inputParameters.device = i
      outputParameters.device = i
      if info.maxInputChannels >= 2:
        ptIn = ctypes.pointer(inputParameters)
      else:
        ptIn = ctypes.c_void_p()
      if info.maxOutputChannels >= 2:
        ptOut = ctypes.pointer(outputParameters)
      else:
        ptOut = ctypes.c_void_p()
      print "    Speeds for 2-channel paInt32:",
      for speed in (44100, 48000, 96000, 192000):
        if pa.Pa_IsFormatSupported(ptIn, ptOut, ctypes.c_double(speed)) == 0:
          print "  %d" % speed,
      print
  finally:
    print 'Close', pa.Pa_Terminate()

  ProblemType: Crash
  DistroRelease: Ubuntu 12.04
  Package: python2.7-minimal 2.7.3~rc1-1ubuntu2
  ProcVersionSignature: Ubuntu 3.2.0-19.30-generic 3.2.11
  Uname: Linux 3.2.0-19-generic x86_64
  ApportVersion: 1.94.1-0ubuntu2
  Architecture: amd64
  Date: Sun Mar 18 11:46:40 2012
  ExecutablePath: /usr/bin/python2.7
  InstallationMedia: Lubuntu 12.04 "Precise Pangolin" - Alpha amd64 (20120307)
  ProcCmdline: python portaudio.py
  Signal: 6
  SourcePackage: python2.7
  UpgradeStatus: Upgraded to precise on 2012-03-10 (8 days ago)
  UserGroups: adm cdrom dip lpadmin plugdev sambashare sudo

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