Resample Quality Switch

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plastedre
Posts: 30
Joined: Fri Jun 05, 2015 8:41 am

Resample Quality Switch

Postby plastedre » Sun May 22, 2016 5:31 am

Is it possible to have a combo list to switch from different resample quality (like in FL Studio).

Example :
  • Linear
  • Hermine
  • 16 point sync
  • ...
  • 512 point sync

I have tested a lot of single cycle wav (like those found on Prophet VS or PPG Wave 2.2) with a key note of F4 there is a lot of aliasing from C6 How to avoid this without multisampling.

Thanks.

davidv
Site Admin
Posts: 1567
Joined: Tue Mar 02, 2004 7:23 pm
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Re: Resample Quality Switch

Postby davidv » Tue May 24, 2016 12:41 pm

First make sure the loop end point matches the WAV spec. the end point is played (inclusive) lots of other wav editors/players interpret it the wrong way.
David Viens,
Plogue Art et Technologie Inc. Montreal.
http://www.plogue.com

plastedre
Posts: 30
Joined: Fri Jun 05, 2015 8:41 am

Re: Resample Quality Switch

Postby plastedre » Tue May 24, 2016 3:39 pm

The wav file is a sample (44.1 Khz, 16 bits, mono) made from 32 single cycle waveform (The first 32 waveform from the Prophet VS). Each single cycle has a loop length of 512. The loop points are within the SFZ file with 32 regions and the use of seq_position opcode to make a pseudo random sound.

Here is an example of my SFZ file :

Code: Select all

<group>
sample=Waves\wavetable.prophet-vs.1.wav
hikey=g6
key=f3
tune=28
lokey=c0
bend_down=-1200 bend_up=1200
seq_length=32
ampeg_release=3

// wavetable : 0 * 512 = 0
<region> offset=0 loop_start=0 loop_end=512 seq_position=1

// wavetable : 1 * 512 = 512
<region> offset=512 loop_start=512 loop_end=1024 seq_position=2

// wavetable : 2 * 512 = 1024
<region> offset=1024 loop_start=1024 loop_end=1536 seq_position=3

// wavetable : 3 * 512 = 1536
<region> offset=1536 loop_start=1536 loop_end=2048 seq_position=4

// wavetable : 4 * 512 = 2048
<region> offset=2048 loop_start=2048 loop_end=2560 seq_position=5

// wavetable : 5 * 512 = 2560
<region> offset=2560 loop_start=2560 loop_end=3072 seq_position=6

...


I have the same problem with one single cycle with loop points in the wav file.

So where i made a mistake ?

pljones
Posts: 100
Joined: Wed Oct 15, 2014 2:05 pm

Re: Resample Quality Switch

Postby pljones » Tue May 24, 2016 3:58 pm

Exactly as davidv wrote
loop_start=0 loop_end=512
That's 513 samples. You want 512 samples.

plastedre
Posts: 30
Joined: Fri Jun 05, 2015 8:41 am

Re: Resample Quality Switch

Postby plastedre » Wed May 25, 2016 3:05 am

Ok i understand the principe (end point is inclusive).

So i change my SFZ (see attachment) code with a simple loop (loop_length = loop_end - loop_start + 1) to this :

Code: Select all

<control>
hint_ram_based=1
hint_min_samplerate=5644800 // 44100 * 2^7 (chipsounds)

set_cc1=0
label_cc1=gate

<group>
sample=smp\wavetable.prophet-vs.1.wav
hikey=c8
key=f4
lokey=c0
bend_down=-1200 bend_up=1200
ampeg_release=3
loop_mode=loop_continuous

<region> offset=10240 loop_start=10240 loop_end=10751



I have no aliasing but the loop become one-shot from A6 to C8, how to avoid this ?

I tested the same sample on Cwitec TX16Wx sampler with the same loop points and there is no problem (just aliasing from c8 to b9).
Attachments
single-cycle.zip
SFZ File with single cycle wavetable wav file
(33.41 KiB) Downloaded 39 times

eric_telemaque
Posts: 215
Joined: Tue Jan 31, 2012 1:10 pm

Re: Resample Quality Switch

Postby eric_telemaque » Wed May 25, 2016 11:59 am

Hi,

I tried your sfz, it plays fine up to F7 here, which is normal. By design, sforzando will play a sample up to 8x its original speed for efficiency and sound quality reasons.
Éric Patenaude,
Plogue Art et Technologie Inc. Montreal.
http://www.plogue.com

plastedre
Posts: 30
Joined: Fri Jun 05, 2015 8:41 am

Re: Resample Quality Switch

Postby plastedre » Wed May 25, 2016 1:22 pm

Thank you for your answers.

I'm sorry to insist but how to work around this behavior and have a linear interpolation (Title of the post) ?

My idea behind this question is how to use single cycle waveform (without multisampling and which covers all the notes of the keyboard) to create sfz preset inspired by the architecture of synth as PPG Wave, Prophet VS or a D-50 (to create old School style synth presets) ?

Is it a feature Request ?

plastedre
Posts: 30
Joined: Fri Jun 05, 2015 8:41 am

Re: Resample Quality Switch

Postby plastedre » Sat May 28, 2016 11:56 am

I'm really sorry to bother you again on this subject but I tested my SFZ file in Cakewalk SFZ (SFZ 1.0) and aliasing started after C8 (in draft mode !). I am disappointed that Sforzando (most efficient player) does not have this feature that does not require much CPU resource.

Sforzando still remains a high quality SFZ player with a lot of features but i can't be use like a super synth/sampler without multisampling. My dream would be to see a sample player in Sforzando that can play a sample across the keyboard(with aliasing begin from the key C8) to create a most sophisticated synth like TableWarp2.

Thanks anyway.
Attachments
single-cycle SFZ.zip
I changed the file to work properly on Cakewalk SFZ
(33.43 KiB) Downloaded 44 times

eric_telemaque
Posts: 215
Joined: Tue Jan 31, 2012 1:10 pm

Re: Resample Quality Switch

Postby eric_telemaque » Mon May 30, 2016 12:30 pm

the intention behind sforzando is to make clean sounding multi-sampled instruments.
Tablewarp2 goes beyond that by being custom code written for sforzando.

You could maybe work around this by making multiple copies of you single cycle in a sample?
Éric Patenaude,
Plogue Art et Technologie Inc. Montreal.
http://www.plogue.com

plastedre
Posts: 30
Joined: Fri Jun 05, 2015 8:41 am

Re: Resample Quality Switch

Postby plastedre » Thu Jun 02, 2016 6:09 am

Do you mean a sample with :
  • one single-cycle for each note (eg. C2 + C3 + C4 + C5 + C6),
    or
  • the same single-cycle repeated several times.

With 1 second single-cycles repeated in a sample i have the same behavior (sample length = 44100, note=C4), no sound after C7.

The solution I have chosen is to use 3 or 4 samples on the keyboard I get very good result with more work on the SFZ file (copy of <group>/<region>s). Thanks to the flexibility of the SFZ format, i will automate the creation of <group>/<region>s with a script in Bash or Python.

Thank you for your help.


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