Animate objects in Maya using sound from the microphone

maya_audio_anim.py

#!/usr/bin/python
# This script opens an ALSA pcm for sound capture, and keyframes the
# object's 'radius' attribute while looping through the sound input.

import sys
import time
import maya.cmds as cmds

# If not installed, install alsa audio by running `pip install pyalsaaudio`
sys.path.append('/usr/local/lib/python2.7/dist-packages')
import alsaaudio
import audioop


def mapValue(rawValue):
    oldMin, oldMax = 3072, 32100
    newMin, newMax = 1, 20
    oldRange = (oldMax - oldMin)
    newRange = (newMax - newMin)
    newValue = (((rawValue - oldMin) * newRange) / oldRange) + newMin
    return newValue


# Open the device in nonblocking capture mode. The last argument could
# just as well have been zero for blocking mode. Then we could have
# left out the sleep call in the bottom of the loop
inp = alsaaudio.PCM(alsaaudio.PCM_CAPTURE, alsaaudio.PCM_NONBLOCK)

# Set attributes: Mono, 8000 Hz, 16 bit little endian samples
inp.setchannels(1)
inp.setrate(8000)
inp.setformat(alsaaudio.PCM_FORMAT_S16_LE)

# The period size controls the internal number of frames per period.
# The significance of this parameter is documented in the ALSA api.
# For our purposes, it is suficcient to know that reads from the device
# will return this many frames. Each frame being 2 bytes long.
# This means that the reads below will return either 320 bytes of data
# or 0 bytes of data. The latter is possible because we are in nonblocking
# mode.
inp.setperiodsize(160)

# Iterate over 48 frames (2 seconds)
for n in range(0, 48):
    # Read data from device
    l, data = inp.read()
    if l:
        # Return the maximum of the absolute value of all samples in a fragment.
        rawValue = audioop.max(data, 2)
        # Map value to a smaller range in order to limit the object's animation
        mappedValue = mapValue(rawValue)
        # Keyframe object
        cmds.setAttr('polySphere1.radius', mappedValue)
        cmds.setKeyframe('polySphere1.radius')
        # Step to next frame in the timeline
        cmds.currentTime(cmds.currentTime(query=True) + 1)
    time.sleep(0.04166)