Create wavlibraryexample.py

Re-implementations of the files to read/write wav data using the wave library instead of scipy. Used here to illustrate why you probably want to use the scipy library (it's much simpler).

wavlibraryexample.py

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+# Using http://docs.python.org/2/library/wave.html
+# aka "why we use scipy"
+# an alternative implementation of the functions getwavdata and makewav
+# as defined in sigproc-outline.py
+
+import wave
+import struct
+
+# performs the same function as getwavdata
+# using the wave library instead of scipy
+def wgetwavdata(file):
+    # open a file for writing
+  infile = wave.open(file, 'r')
+	length = infile.getnframes()
+	data = []
+	for i in range(length):
+	    nextframe = infile.readframes(1)
+		# this returns C-style little-endian shorts, so we convert...
+		data += struct.unpack("<h", nextframe)
+	return data
+
+# performs ALMOST the same function as makewav
+# using the wave library instead of scipy
+# note that the 3rd argument is params rather than samplerate
+# and that the 3rd element of params is the sample rate
+# (see notes below)
+def wmakewav(data, outfile, params=(1,2,44100, 0, 'NONE', 'not compressed')):
+    wavfile = wave.open(outfile, 'w')
+	wavfile.setparams(params)
+	# convert back to C-style little-endian shorts...
+	converted = [struct.pack("<h", i) for i in data]
+	outdata = ''
+	for i in converted:
+	    outdata += i[0]
+		outdata += i[1]
+	wavfile.writeframes(outdata)
+	wavfile.close()
+
+# Regarding params:
+# arguments are (nchannels, sampwidth, framerate, nframes, comptype, compname)
+# nchannels is 1 for stereo and 2 for mono
+# sampwidth is the number of bytes per sample, usually 1 or 2
+# framerate is the sample rate, 44100 is common for CDs
+# nframes is the number of frames
+# comptype is compression type
+# compname is the human-readable name for comptype