Using any other values in pyaudio for rate / format / chunk give me the error: [Errno Input overflowed] -9981

Question

OS: Mac OSX 10.7.5 Python: Python 2.7.3 (homebrew) pyaudio: 0.2.7 portaudio: 19.20111121 (homebrew - portaudio)

The following script outputs the following and displays the issues I am having:

#!/usr/bin/env python
import pyaudio
from pprint import pprint

p = pyaudio.PyAudio()


# SUCCEEDS
pprint(p.is_format_supported(input_format=pyaudio.paInt8,input_channels=1,rate=44100,input_device=0)) # => True
try:
    stream = p.open(format=pyaudio.paInt8,channels=1,rate=44100,input=True,frames_per_buffer=1024)
    data = stream.read(1024)
except IOError as e:
    print 'This never happens: '+str(e)

# FAILS
pprint(p.is_format_supported(input_format=pyaudio.paInt8,input_channels=1,rate=22050,input_device=0)) # => True
try:
    stream = p.open(format=pyaudio.paInt8,channels=1,rate=22050,input=True,frames_per_buffer=1024)
    data = stream.read(1024)
except IOError as e:
    print 'This fails: '+str(e)

# FAILS
pprint(p.is_format_supported(input_format=pyaudio.paInt8,input_channels=1,rate=22050,input_device=0)) # => True
try:
    stream = p.open(format=pyaudio.paInt8,channels=1,rate=22050,input=True,frames_per_buffer=512)
    data = stream.read(1024)
except IOError as e:
    print 'This also fails: '+str(e)

# FAILS
pprint(p.is_format_supported(input_format=pyaudio.paInt8,input_channels=1,rate=11025,input_device=0)) # => True
try:
    stream = p.open(format=pyaudio.paInt8,channels=1,rate=11025,input=True,frames_per_buffer=512)
    data = stream.read(1024)
except IOError as e:
    print 'This also fails as well: '+str(e)

stream.stop_stream()
stream.close()
p.terminate()

The above outputs the following:

True
True
This fails: [Errno Input overflowed] -9981
True
This also fails: [Errno Input overflowed] -9981
True
This also fails as well: [Errno Input overflowed] -9981

Answer 1

If you want to check whether the desired settings of format, channels, rate, etc. are supported by your OS and hardware, do the following:

import pyaudio
soundObj = pyaudio.PyAudio()

# Learn what your OS+Hardware can do
defaultCapability = soundObj.get_default_host_api_info()
print defaultCapability

# See if you can make it do what you want
isSupported = soundObj.is_format_supported(input_format=pyaudio.paInt8, input_channels=1, rate=22050, input_device=0)
print isSupported

isSupported will be True incase your system can deal with your settings. The memory overflow errors might be due to some OS+Hardware issues. You must check what your default host API can actually do. You don't need to "open" and "close" the soundObj via the "stream class" for querying it.

Have a look at this SO question: PyAudio Input overflowed

For additional pyaudio documentation and help visit:

http://people.csail.mit.edu/hubert/pyaudio/docs/

Edit:

It turns out that "Errno Input overflowed - 9981" is not a trivial issue: http://trac.macports.org/ticket/39150

I see that you have the latest portaudio version (19.20111121) but 19.20111121_4 claims to have fixed the bug. See if upgrading portaudio works.