Converting & loading samples for MSX-Audio

Mr. Ambassadors (1790)

19-11-2016, 15:49

So for a project of mine, I'm trying to load samples I have on the PC and play them back on the MSX-Audio (Music Module atm). From years ago I remember I converted some samples with the Windows program Cooledit with some specific settings and I was able to load those into Moonblaster. Unfortunately I don't remember anymore what I did, and any experiments haven't worked so far.

So, a question... anyone has a good idea on how to convert (short) WAV files to a format I can play back on the MSX-Audio? Preferably automated because we're talking about a lot of samples. Doesn't necessarily have to be in Moonblaster, any other program is also fine as long as it's able to play back the samples on MSX-Audio so I can record it.

Any ideas?

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Par ARTRAG

Enlighted (6935)

19-11-2016, 15:59

try the OPLL4.RAR files from here
https://sites.google.com/site/voicesynthesisontheisr/home/te...
explanation is here
https://www.msx.org/forum/msx-talk/development/voice-synthes...

Par giangiacomo.zaffini

Champion (267)

19-11-2016, 16:03

Hi Jorito, navigating the internet it seems I had read about such things ...
but I don't remember where ...
for a start Tarosan in its FSW site has something for MSX turboR PCM channel
PCMconversion utility link
Let's see if I find something for MSX-AUDIO.
Ciao

Par meits

Scribe (6542)

19-11-2016, 17:37

A windows tool called goldwave can do batch conversion. I've forgotten which exact ADPCM settings you need. Just PCM won't do it...
Convert a few and check if the samples are okay... You don't want to edit the start address once they're ADPCM since that will destroy the sample...

Par Jorito

Mr. Ambassadors (1790)

19-11-2016, 19:20

I didn't really understand the explanation page for the OPL4.RAR files, but the name suggests it's for the OPL4?

Batch conversion to ADPCM should be easy enough; I know it's ADPCM but the few conversions I've tried didn't work unfortunately. If I have to, I will guess and try all different combinations, but I'd rather not

Par giangiacomo.zaffini

Champion (267)

19-11-2016, 19:28

I'm not an expert here, but I guess MSX-AUDIO can do both ADPCM and PCM,
see e.g. BASIC extension commands LOAD PCM and PLAY PCM.

Par ARTRAG

Enlighted (6935)

19-11-2016, 20:55

Sorry for the misleading name but the sample player is for OPLL
It is just revision 4 of the program

Par giangiacomo.zaffini

Champion (267)

19-11-2016, 23:23

last for today
since those international standards
ITU (formerly CCITT) G.721 4-bit ADPCM format data.
ITU (formerly CCITT) G.723 3 or 5-bit ADPCM format data.
ITU (formerly CCITT) G.726 2, 3, 4 or 5-bit ADPCM format data.
any tool converting into those format should be of interest (header od headerless format I don't know, but a hex editor will axe any problem).
For instance SC Audio CD creator
Ciao

Par Jorito

Mr. Ambassadors (1790)

19-11-2016, 23:29

Thanks for the help guys, I'll check it out tomorrow

Par giangiacomo.zaffini

Champion (267)

20-11-2016, 02:18

no frills!
from XelaSoft (@ The MSX Plaza)
look for
Assembler library (in gen80 format) for ADPCM <-> PCM conversion
C library for ADPCM <-> PCM conversion
Ciao

Par NYYRIKKI

Enlighted (6067)

20-11-2016, 09:43

Seems that pretty much everyone is answering to different question that was asked

That mentioned XelaSoft tool is only tool that I know to handle MSX-Audio ADPCM data. I've tried that long long time ago, but I was a bit disappointed to resulting sample volume. I think the algorithm is made to maximize SNR, but at the same time it makes the sample very quiet. (I think fixing this would be perfect challenge to ARTRAG as he seems to be our signal processing expert )

@giangiacomo.zaffini Direct quote from XelaSoft read.me: "ADPCM samples must be in 4-bits packed MSX AUDIO format. The MSX AUDIO format is not compliant with the CCITT ADPCM format," Although you can play/record also PCM samples with MSX-AUDIO it is pretty useless as it works like in MSX tR. It is not practically usable for games or demos since it requires pretty much all of Z80 CPU power. ARTRAG's method of playing with MSX-MUSIC is already much better, but playing ADPCM samples is practically free after you have uploaded the sample data to MSX-AUDIO.

I would be also very interested if someone finds a PC tool that handles this audio data properly.