utils: add audio conversion script, update image creation

utils/wav2tdrau.py

@@ -0,0 +1,29 @@
+import sys
+import random, struct
+import wave
+
+freq = 16000
+BIAS = 32768
+def convert(srcpath, destpath):
+	outdata = bytearray()
+	with wave.open(srcpath, mode="rb") as f:
+		params = f.getparams()
+		print(params.nchannels, params.sampwidth, params.framerate)
+
+		frames = f.readframes(2*1024*1024)
+		for i in range(0, len(frames), 2):
+			v = int.from_bytes(frames[i:i+2], "little", signed=True)
+			v += BIAS
+			hi = (v & 0xFF00) >> 8
+			lo = (v & 0x00FF)
+			outdata.append(hi)
+			outdata.append(lo)
+
+	with open(destpath, mode="wb") as f:
+		f.write(outdata)
+
+
+if __name__ == "__main__":
+	sourcefilename = sys.argv[1]
+	destfilename = sys.argv[2]
+	convert(sourcefilename, destfilename)