annotate util.py @ 1:04f1e3463466 tip master

Implement maxpooling and unpooling aspect

# utility functions

import numpy as np
from numpy import float32

import os, errno
from scikits.audiolab import Sndfile
from scikits.audiolab import Format

from matplotlib.mlab import specgram

from userconfig import *

########################################################

def standard_specgram(signal):
	"Return specgram matrix, made using the audio-layer config"
	return np.array(specgram(signal, NFFT=audioframe_len, noverlap=audioframe_len-audioframe_stride, window=np.hamming(audioframe_len))[0][specbinlow:specbinlow+specbinnum,:], dtype=float32)

def load_soundfile(inwavpath, startpossecs, maxdursecs=None):
	"""Loads audio data, optionally limiting to a specified start position and duration.
	Must be SINGLE-CHANNEL and matching our desired sample-rate."""
	framelen = 4096
	hopspls = framelen
	unhopspls = framelen - hopspls
	if (framelen % wavdownsample) != 0: raise ValueError("framelen needs to be a multiple of wavdownsample: %i, %i" % (framelen, wavdownsample))
	if (hopspls  % wavdownsample) != 0: raise ValueError("hopspls  needs to be a multiple of wavdownsample: %i, %i" % (hopspls , wavdownsample))
	if maxdursecs==None:
		maxdursecs = 9999
	sf = Sndfile(inwavpath, "r")
	splsread = 0
	framesread = 0
	if sf.channels != 1:       raise ValueError("Sound file %s has multiple channels (%i) - mono required." % (inwavpath, sf.channels))
	timemax_spls   = int(maxdursecs * sf.samplerate)
	if sf.samplerate != (srate * wavdownsample):
		raise ValueError("Sample rate mismatch: we expect %g, file has %g" % (srate, sf.samplerate))
	if startpossecs > 0:
			sf.seek(startpossecs * sf.samplerate) # note: returns IOError if beyond the end
	audiodata = np.array([], dtype=np.float32)
	while(True):
		try:
			if splsread==0:
				chunk = sf.read_frames(framelen)[::wavdownsample]
				splsread += framelen
			else:
				chunk = np.hstack((chunk[:unhopspls], sf.read_frames(hopspls)[::wavdownsample] ))
				splsread += hopspls
			framesread += 1
			if framesread % 25000 == 0:
				print("Read %i frames" % framesread)
			if len(chunk) != (framelen / wavdownsample):
				print("Not read sufficient samples - returning")
				break
			chunk = np.array(chunk, dtype=np.float32)
			audiodata = np.hstack((audiodata, chunk))
			if splsread >= timemax_spls:
				break
		except RuntimeError:
			break
	sf.close()
	return audiodata

def mkdir_p(path):
    try:
        os.makedirs(path)
    except OSError as exc: # Python >2.5
        if exc.errno == errno.EEXIST and os.path.isdir(path):
            pass
        else: raise