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Typical signal to noise ratio of ADPCM
Neuron
post Jan 28 2013, 15:08
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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.
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Neuron
post Jan 29 2013, 22:42
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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
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Neuron
post Jan 29 2013, 23:15
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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:

QUOTE
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
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bandpass
post Jan 30 2013, 08:46
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QUOTE (Neuron @ Jan 29 2013, 22:15) *
MS ADPCM has a far lower noise level in my opinion...

This is not unexpected as it uses a 2nd-order predictor (IMA & OKI ADPCM are 1st order).
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Posts in this topic
- Neuron   Typical signal to noise ratio of ADPCM   Jan 28 2013, 15:08
- - saratoga   There are various adpcm flavors. Which are you usi...   Jan 28 2013, 16:56
|- - Neuron   QUOTE (saratoga @ Jan 28 2013, 16:56) The...   Jan 28 2013, 20:16
- - Garf   CompAudio from AFsp can calculate this, IIRC. But ...   Jan 28 2013, 17:51
|- - Woodinville   QUOTE (Garf @ Jan 28 2013, 08:51) CompAud...   Jan 31 2013, 08:30
- - kode54   Cool, game soundtrack ripping for the win. I may b...   Jan 29 2013, 06:07
|- - Neuron   QUOTE (kode54 @ Jan 29 2013, 06:07) Cool,...   Jan 29 2013, 11:54
|- - Neuron   QUOTE (kode54 @ Jan 29 2013, 06:07) Cool,...   Jan 29 2013, 16:47
- - Neuron   Here it is:http://www.hydrogenaudio.org/forums/ind...   Jan 29 2013, 12:46
- - saratoga   If you have the lossless and lossy encoded files y...   Jan 29 2013, 17:37
- - Neuron   I have to admit I don't really know how to do ...   Jan 29 2013, 22:42
|- - Neuron   I've added the song in 44 Khz MS ADPCM to the ...   Jan 29 2013, 23:15
||- - bandpass   QUOTE (Neuron @ Jan 29 2013, 22:15) MS AD...   Jan 30 2013, 08:46
|- - Woodinville   QUOTE (Neuron @ Jan 29 2013, 13:42) I hav...   Jan 31 2013, 08:33
- - extrabigmehdi   Well, I used the normalize function of soundforge ...   Jan 30 2013, 00:08
|- - Neuron   QUOTE (extrabigmehdi @ Jan 30 2013, 00:08...   Jan 30 2013, 11:29
|- - extrabigmehdi   QUOTE (Neuron @ Jan 30 2013, 10:29) Thank...   Jan 30 2013, 13:48
- - Neuron   Thank you, but what does "signal: -19 db...   Jan 30 2013, 14:14
|- - db1989   QUOTE (Neuron @ Jan 30 2013, 13:14) ADPCM...   Jan 30 2013, 15:29
|- - extrabigmehdi   QUOTE (Neuron @ Jan 30 2013, 13:14) Thank...   Jan 30 2013, 15:49
|- - Neuron   QUOTE (extrabigmehdi @ Jan 30 2013, 15:49...   Jan 30 2013, 16:07
|- - Neuron   QUOTE (extrabigmehdi @ Jan 30 2013, 15:49...   Jan 30 2013, 16:13
- - pdq   The "dynamic range" of mp3 is actually q...   Jan 30 2013, 15:24
- - Neuron   I did an Audacity convert to mono + match both vol...   Jan 30 2013, 16:00
|- - extrabigmehdi   QUOTE (Neuron @ Jan 30 2013, 15:00) I got...   Jan 30 2013, 17:03
||- - Neuron   QUOTE (extrabigmehdi @ Jan 30 2013, 17:03...   Jan 30 2013, 21:04
|- - saratoga   QUOTE (Neuron @ Jan 30 2013, 10:00) I did...   Jan 30 2013, 18:20
|- - Neuron   QUOTE (saratoga @ Jan 30 2013, 18:20) So ...   Jan 30 2013, 21:24
|- - saratoga   QUOTE (Neuron @ Jan 30 2013, 15:24) QUOTE...   Jan 31 2013, 01:44
|- - Neuron   QUOTE (saratoga @ Jan 31 2013, 01:44) QUO...   Jan 31 2013, 13:44
- - Neuron   That is true, but it does not explain why the ADPC...   Jan 30 2013, 21:10


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