2.0.3 - 10.8.4 MS ADPCM Conversion causing major distortion

[strikingtwice]

This is a file that I've exported as "Other Uncompressed Format" MS ADPCM. The game engine we're using currently uses this for streaming sources. Exporting causes some unusable distortion. I recently was going to purchase another program called twisted wave for this, he recently updated the library and it doesn't cause distortion. What library is audacity using for MS ADPCM compression?

This is the file link.
https://www.dropbox.com/s/k0xvuq5co8ovy ... ressed.wav

[steve]

Considering that ADPCM is only a 4 bit format I think that sounds as good as can be expected. ADPCM is a very old compressed format that was developed for telephony, It still performs quite well for voice quality applications (though more recent formats such as Speex perform better) and is relatively easy to implement in hardware. For compressing music it has been superseded by "modern" formats such as MP3, OGG, WMA, AC3...

I'm not certain what library Audacity uses but I'd guess libsndfile.
I tested the on-line version of twisted wave and the MS ADPCM encoding is virtually identical to Audacity.

[strikingtwice]

No, here's an export from the desktop version.
TwistedWave
https://www.dropbox.com/s/1c18yrtxrqaen ... wisted.wav
Audacity
https://www.dropbox.com/s/taxgutr2ypp6d ... dacity.wav

I'm not talking about overall sound quality, i'm talking about bursts of distortion. The old version of twistedwave gave me the exact issue, but he corrected. I believe the new library that he replaced it with is SoX or something. I think the libsnd is what he was using before.

I understand that MSADPCM sucks and that it's not the ideal format for modern sound, however it is what the engine that we are using uses. It's not the format that I would choose if I were working on it.

http://sox.sourceforge.net/

[steve]

You mean the short bursts of noise, like at 2.169 to 2.218 seconds?
I don't know what they are. I'll see if I can reproduce the issue. It may help if you could post an uncompressed MS PCM WAV file version so I can test that.

[Gale Andrews]

No, here's an export from the desktop version.
TwistedWave
https://www.dropbox.com/s/1c18yrtxrqaen ... wisted.wav
Audacity
https://www.dropbox.com/s/taxgutr2ypp6d ... dacity.wav

I'm not talking about overall sound quality, i'm talking about bursts of distortion.

I'm afraid my ears are too old to hear very subtle difference as those two files seem to have. I would find the Audacity file perfectly acceptable - it's only in comparison to the twisted wave version that it sounds to me marginally less clean, plus perhaps it has an odd suspicion of masked crackle in the background.

If other than the places Steve mentioned, can you point to an exact timeline spot in the Audacity file to listen for?

Exactly what is your workflow to produce that file in Audacity? Are you mixing imported files together? Are any of the files offset from time zero?



Gale

[strikingtwice]

Thanks for the reply Gale. It's not a subtle difference in the compression that i'm talking about, i wouldn't care about that, nor could my ears hear it either!

It's actually the static crackles. If you listen from about 8 seconds on, you'll hear some fairly consistent crackling. Especially after larger peaks.

All I'm doing with the files is making them in Logic and bouncing them as wav, then open in audacity and save as. Nothing is offset or anything like that.

[steve]

It's actually the static crackles. If you listen from about 8 seconds on, you'll hear some fairly consistent crackling. Especially after larger peaks.

You mean like this:

You mean the short bursts of noise, like at 2.169 to 2.218 seconds?

[Robert J. H.]

[...]I'm not talking about overall sound quality, i'm talking about bursts of distortion. The old version of twistedwave gave me the exact issue, but he corrected. I believe the new library that he replaced it with is SoX or something. I think the libsnd is what he was using before.

The producer ID is Logic Pro X (according to Media-Info).

[strikingtwice]

No, the original content creator was logic pro x. Twisted wave apparently does not strip the wave's authoring program from meta.

I'm talking more about between 8 and 9 seconds after the two drum clacks you can hear pfft pfft pfft static sounds.

[Robert J. H.]

The difference is fairly obvious.
I've normalized both files and inverted one.
The remaining sound is quite abominable.

intro_for_loop_comparison.wav

Start at 18 s

(861.37 KiB) Downloaded 65 times

Especially drum rolls, noisy and high sounds seem to differ the most.