Looping Samples?

neilbaldwin

Is it possible already with the current firmware?

I was going to start hacking around in the code to make it work but I thought I'd better ask first!

cj55

Edit: sorry, didn't read you question right.

neilbaldwin

It was easy enough to get it working but I guess it could do with a 'Loop Yes/No' parameter as you wouldn't want it on for transient samples.

There's a space on the OSC page to have a parameter next to 'WAV'' but it's going to take me a lot longer to figure that bit out!

 

The alternative would be to somehow encode it into the sample so that it can be interpreted by the sample loading routine.

neilbaldwin

I managed to create a new parameter 'SLOOP' thanks to the rather excellent guide on the wiki but I can't seem to get the sample buffer refresh to recognise the parameter, or possibly it's not getting set from the midi parser code (but I don't think that's true....read on)

I've added a parameter to the OscInfo structure:

typedef struct OscStruct

{

int16_t output;

uint32_t phaseInc;

uint32_t phase; // the current phase of the osc 8bit indexing 24 interpolation

float freq; // frequency in [Hz]

uint8_t waveform; // the selected waveform of the osc

uint8_t tableOffset; //overtone table

float pitchMod; // modulation value for frequency

float fmMod;

float modNodeValue;

//for midi

uint16_t midiFreq;  //upper 8 bit coarse, lower 8 bit fine -> the sound edit freq offset

uint8_t baseNote; // the last played midi note

uint32_t startPhase; // the OSC is reset to this phase on retrigger

uint8_t sloop;

} OscInfo;

In MIDIPARSER.C I'm doing this:

case CC2_PAR_SLOOP1:

{

//voiceArray[0].vol = msg.data2/127.f; 

voiceArray[0].osc.sloop = msg.data2;

}

In OSCILLATOR.C in the sample buffer update code I'm doing this:

if(itg < info.size)

{

osc->phase = oscPhase + osc->phaseInc;

} else {

if (osc->sloop > 63)

{

osc->phase = 0;

}

}

buf[i] = oscOut * gain;

If I remove the osc->sloop > 63 condition, the looping works. With the condition in place it's always off.

In the MIDIPARSER code, the line that is commented out that sets the oscillator volume was put in as a test to check if the value is getting set at that point. With this line in, the oscillator volume gets set as you'd expect.

Any ideas?

egnouf

Hello :-)
stupid question, how is setup the CC2_PAR_SLOOP1 parameter?
is it an : DTYPE_1B16, DTYPE_ON_OFF, DTYPE_0B127, etc ?

it could be that SLOOP nevers reach 64.. because it is a ON OFF parameter (1 and 0) ... or CC2..SLOOP is set to 1 to 16 (DTYPE_1B16) , no?

tell me :-)
regards.

julian

hmmm looks good.
are you using the main oscillator as sample player?
just asking because voiceArray[0].volattenuates the voice output at the very end of the chain (final VCA so to say), but your voiceArray[0].osc.sloop only sets the sloop parameter for the main oscillator, not the fm mod osc or the transient osc.

julian

if you set it to DTYPE_ON_OFF it will be either 0 or 1.
then you should change
if (osc->sloop > 63)
to
if (osc->sloop)
to make it work

neilbaldwin

Thanks Julian, egnouf

It is DTYPE_ON_OFF but I'd also tried it with DTYPE_0B127 when I was debugging the values.

I'll give it another try with that logic in the buffer streaming changed.

neilbaldwin

Oh, and Julian, yes, using the main osc as a sample player though I might try to expand that to the second oscillator too as it might yield some interesting results.

neilbaldwin

YES!  :-))

Working now, thanks guys. Not really sure what happened: I guess I must've done the classic 'changing more than one thing when debugging' and somehow mixed up the 0/1 logic when I wasn't sure what values were used for a ON_OFF parameter.

I'll do some work on it tonight to code the features properly (especially the MIDI parser bit which was just a test with one single case for voice 0)

It certainly opens up some interesting possibilities: I've got mine loaded with a bunch of single-cycle waveforms which you can now use as an alternative oscillator shape. 

egnouf

Youahhhh , I am looking forward to seeing your new feature :-)
and give us later a github link ;-)
regards.

neilbaldwin

@Julian: I'm a bit confused by the implementation. I have it working fine on Drum 1 to 3 but some of the other synthesis methods, even though you can select a user sample as the oscillator, don't seem to respond to the same looping.

Are there different fetch/fill buffer methods for each synthesis type?

julian

hmmm normally each voice is using the same OscInfo struct for its oscillators.
you should be able to set it accordingly.

there is a difference between fm and non fm oscillators though.
there are two functions: calcNextOscSampleBlock() and calcNextOscSampleFmBlock()
regarding the samples: calcUserSampleOscFmBlock() and calcUserSampleOscBlock()

maybe you only implemented it in one of those?

neilbaldwin

Not at computer now but will check later. I definitely only implemented it in 2 functions so you're probably correct.

Thanks Julian

Whiteherbman

waiting for your github
>:D<

neilbaldwin

Julian: can you confirm that you're able to use user samples as the FM secondary oscillator? You can select a sample but my looping trick doesn't work and I was wondering if it was the looping at fault or whether you've not implemented that yet?

Neil