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Re: FM synth BRR sample generator

Posted: Sat Mar 11, 2017 3:18 pm
by psycopathicteen
I implemented all 8 algorithms but I'm having a quantization noise problem with algorithm 7. In order find the BRR "range" I just added up the carrier volumes, and counted the number of 0 bits at the top. If you have several carriers that are slightly detuned they could cancel each other out, which would turn into a square wave with only 4 bit samples. I guess I just have to find the BRR range by checking each sample individually.

Re: FM synth BRR sample generator

Posted: Thu Mar 23, 2017 4:27 pm
by Augustus Blackheart
psycopathicteen wrote:I implemented all 8 algorithms...
I'm looking forward to hearing what that sounds like.

I made this test awhile ago using the original code you posted... I just dropped your code into the middle of the SNESMod vibrato routine. 4xy: x = vibrato speed and carrier frequency, and y = vibrato depth and modulation frequency; but only when the vibrato waveform is $08-$0f. <$08 is just vibrato waveforms. Each time the song repeats the FM waveform is changed.

Channel 1: FM waveform echo

Channel 3+5 FM waveform
Channel 4+6 2nd waveform (pitch modulation enabled)

carrier frequency = #$02
modulation frequency = #$04

I was working on a ROM that would allow you to change various settings maybe I'll dig that up.

Also, it's weird that .spc extension is not allowed.

Re: FM synth BRR sample generator

Posted: Sat Mar 25, 2017 11:01 am
by psycopathicteen
Can BIN be directly used as an SPC file?

Re: FM synth BRR sample generator

Posted: Sat Mar 25, 2017 9:52 pm
by 93143
I just saved it as an SPC file, and it worked.

Re: FM synth BRR sample generator

Posted: Sun Mar 26, 2017 1:34 am
by Bregalad
I tried to play it with both of my SPC players and it sounded awful in both. Is this due to an emulation inacuracy or is it supposed to sound like this ?

Re: FM synth BRR sample generator

Posted: Mon Mar 27, 2017 1:30 pm
by Augustus Blackheart
Bregalad wrote:I tried to play it with both of my SPC players and it sounded awful in both. Is this due to an emulation inacuracy or is it supposed to sound like this ?
It doesn't sound great. I noticed playback varied a lot on each SPC player I tried. After real hardware it probably sounded the best on SPCPlay.

Due to limited RAM I'm only using two BRR blocks. How good it sounds depends on the waveform selected and settings used. The ramp up and ramp down waveforms probably sound the worst unless you are looking for a super glitch-y sound.

I've attached another test and a song, although they probably do not sound much better.

Re: FM synth BRR sample generator

Posted: Mon Mar 27, 2017 6:20 pm
by psycopathicteen
The first half sounds awesome though

Re: FM synth BRR sample generator

Posted: Mon Mar 27, 2017 8:36 pm
by Drew Sebastino
Augustus Blackheart wrote:It doesn't sound great.
What is causing this? It sounds like an electronic voice crack at 22 seconds in.

Re: FM synth BRR sample generator

Posted: Tue Mar 28, 2017 2:17 am
by Optiroc
Wow, this is awesome!

Re: FM synth BRR sample generator

Posted: Mon Aug 28, 2017 7:03 am
by Augustus Blackheart
Here's another example (made during a shocking international incident). There's one version with FM and pitch modulation, it's used starting one minute into the song, and one version with pitch modulation only.