CODEWITHSUNDEEP
audiowavcodec
justoneguy
justoneguy

Reputation: 11

Need help to find out WAVE file's coding

I'm modding a game and need some help with a WAVE file that I've been trying to change. It seems like that the game has used some kind of weird coding and I can't get any program to regocinize it correctly. I tried to open it up in hex editor, but the Codec ID points to normal PCM file, however playing it results only white noise. I got the best results by opening the file as RAW VOX ADPCM in Audacity, but the audio is still very messy and distorted.

Also, theres an older game by the same creators which has the exactly same files except that they are normal WAVE files, so I was able to provide a comparison:

Unknown coding: https://www.dropbox.com/s/gvlqu2ryu8jwfe3/ColumnCrumble.snd
Normal coding: https://www.dropbox.com/s/3lo2m0wdg43b0q1/ColumnCrumble.wav

Upvotes: 1

Views: 507

Answers (1)

jaket
jaket

Reputation: 9341

It's highly likely the encoded file ADPCM since:

  1. as @dB mentions, the .snd file is 1/4 the size and ADPCM is 4-bits/sample vs. 16 for regular PCM.

  2. It resembles the expected result when played as ADPCM in audacity.

The distortion you're experiencing might just be a limitation of ADPCM. PCM is able to swing around at a high frequency (2^16 per sample). ADPCM is only able to swing 2^4 per sample and so is slew rate limited. Also, looking at the spectrum of the .wav file, there is quite a bit of high frequency content.

Finally, if you were to patch up the malformed wave format in the encoded file's header so that it indicated ADPCM, it would probably play okay in most players.

Upvotes: 2

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