Typical signal to noise ratio of ADPCM Options

[Neuron]

So, I have decided to return to this forum (despite my little conflict with greynol) and I have kind of a weird question. I would like to know what is the rough SNR of a 4-bit ADPCM recording (IMA and Microsoft). For those curious why I am asking this, well, I like ripping music and sound effects from old games, and I would like know the technical side as well.

[Neuron]

I have to admit I don't really know how to do such a thing but I've found something http://www.baudline.com/solutions/codec/index.html .

The curious thing is, why does ADPCM achieve lower SNR than 8-bit PCM according to that website even through ADPCM usually sounds much better? Is it because a sine wave was used? Same for u and A-law, I thought they were supposed to increase SNR (and u-law and A-law files indeed hear much cleaner than linear 8 bit).

This post has been edited by Neuron: Jan 29 2013, 22:44

[Neuron]

I've added the song in 44 Khz MS ADPCM to the sample thread. MS ADPCM has a far lower noise level in my opinion and I provide an ABX test here:

foo_abx 1.3.4 report
foobar2000 v1.1.16
2013/01/29 22:59:35

File A: C:\Documents and Settings\Administrator.MISO-33497FE14F.000\My Documents\Med Sci 1 msadpcm.wav
File B: C:\Documents and Settings\Administrator.MISO-33497FE14F.000\My Documents\Med Sci 1 dvi.wav

22:59:35 : Test started.
23:00:14 : 01/01 50.0%
23:00:23 : 02/02 25.0%
23:00:34 : 03/03 12.5%
23:00:43 : 04/04 6.3%
23:01:01 : 05/05 3.1%
23:01:23 : 06/06 1.6%
23:01:32 : 07/07 0.8%
23:01:51 : 08/08 0.4%
23:02:06 : 09/09 0.2%
23:02:12 : 10/10 0.1%
23:02:22 : 11/11 0.0%
23:02:31 : 12/12 0.0%
23:02:33 : Test finished.

----------
Total: 12/12 (0.0%)

(For those who wonder why the filenames are different from those in the sample thread, I have renamed them when I uploaded them to the forum, this is how they are named on my harddrive).

This post has been edited by Neuron: Jan 29 2013, 23:16