[lch]

Somebody asked about this on another forum which made me curious to have a look at the problem again, wasted 3 hours of sleep on this... Dealing with the programming from the game before, I expected that it would probably be faithful to the specs - JK is pretty straight forward in this regard, and that all those programs that I used for a-law encoding were to blame for not really writing raw data.

Turns out that my hunch was right. Following a link from the Wikipedia article on A-law encoding (Finland is in Europe, and *.al is a suggestive filename) I had a look at the compression tutorial at http://hazelware.luggle.com/tutorial...mpression.html and then looked if somebody had already implemented something in that direction since I didn't want to write a C/C++ program from scratch. Then I found the audioop module in Python which has A-law since Python 2.5, so I only had to learn Python which was easier than expected with copy&paste from examples. Here's the straight-forward approach to playback the game audio files:

Code:

---

#! /bin/env python

import audioop

alaw_data = open('/opt/dominions3/rawsound/draam13.al', 'r')

pcm = audioop.alaw2lin(alaw_data.read(), 2)



from ossaudiodev import open as ossOpen

dsp = ossOpen('/dev/dsp','w')

try:

	from ossaudiodev import AFMT_S16_NE

except ImportError:

	if byteorder == "little":

		AFMT_S16_NE = ossaudiodev.AFMT_S16_LE

	else:

		AFMT_S16_NE = ossaudiodev.AFMT_S16_BE



dsp.setparameters(AFMT_S16_NE, 2, 11025)



dsp.write(pcm)

dsp.close()

---

I'm not sure if the game audio files are mono at 22050 Hz or stereo at 11025 Hz, I guess it's the latter. The playback is pretty faithful to in-game.

If you convert your source material to raw PCM data, then you can use the following Python script to convert it to raw A-law data:

Code:

---

#! /bin/env python



import sys, string

if len(sys.argv)!= 2:

	print "Usage: "+sys.argv[0]+" <filename>"

	sys.exit()

else:

	inputfile = sys.argv[1]

	name1 = str.split(inputfile, '.')

	outputfile = string.join(name1[:len(name1)-1])+'.al'



import audioop

pcm_data = open(inputfile, 'r')

alaw_data = audioop.lin2alaw(pcm_data.read(), 2)



alaw = open(outputfile, 'w')

alaw.write(alaw_data)

---

Now I looked for some demo input, MP3s on the net and found some Old Tatar Songs which are already at 11kHz. Converting them to *.al format:
Code:

---

$ mpg123 -v -y --stereo --rate 11025 -w kukkuger.pcm kukkuger.mp3

$ python2.5 convert.py kukkuger.pcm

---

Then copied it over /opt/dominions3/rawsound/draam13.al - sounds good!
Here's the demo file: http://www.mediafire.com/?9h2xnxprb1t

Somebody make a better Python program out of this, maybe with a nice GUI. I learned Python just 2 hours ago!