[Coladam] More about tone channels attenuation (volume) -and- digital sounds (PART 4)

Daniel Bienvenu newcoleco at yahoo.fr
Fri Dec 11 19:56:44 CET 2009


After talking with D.Vik about his pcm tests, I've decided to try them on the real console. Like I suspected the sound is different on the real console. So let's hear the result.

You'll hear first my best try so far at 6-bit, the same as in my first sndtest.mp3 file, but captured again to be sure, and right after you'll hear samples from Vik. Notice that I didn't change the speed or volume.

http://www.ccjvq.com/newcoleco/sndtest3.mp3

The quality is impressive for 4bit data. My version at 6bit is louder, but it's probably because my original PCM WAV file is louder that his PCM WAV file. More louder a sound is, more risky it is because, like I said before, the attenuation levels are not well distributed for this purpose of digital sounds. 

Well, if I keep the 6bit version "as is" and forget about the lossy compression, which didn't get a bad result by the way but just not as good of course, I can only hope a 25% reduction if it's stored raw as 4 6bit per 3 bytes, and about the same compression result if I use instead the free 2bit for rle compression... and I don't like the slow down I've while adding codes to support compression. All this to day... there still a lot of work to do if I want something good and well optimized.

Have a nice day!

Daniel


      


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