Re: [music-dsp] MIDI Synth Design Advice Please

Ross Bencina wrote: .. http://epickrram.blogspot.co.uk/2015/09/reducing-system-jitter.html ... Interesting read, centered around java and the idea of calling virtual multiprocessing overhead jitter. Probably some form of thread control is on for attention to optimize complex computations,

Re: [music-dsp] MIDI Synth Design Advice Please

On 2/02/2016 2:10 AM, Scott Gravenhorst wrote: Advice regarding this endeavor would be appreciated In case you haven't found it, you should research the disable_pvt config file flag. It can reduce system jitter a little. Hi again Scott, The following Linux system jitter optimisation blog

Re: [music-dsp] MIDI Synth Design Advice Please

Hi Scott and all, You might also be interested in a low-latency embedded audio platform we are soon releasing called Bela: http://bela.io Bela uses the BeagleBone Black and a custom cape with stereo audio in/out, 8 channels each of 16-bit, DC-coupled analog I/O, and 16 GPIO pins. It uses

Re: [music-dsp] MIDI Synth Design Advice Please

inline... music-dsp@music.columbia.edu wrote: >Hello all, Hello Scott, > >I've followed this thread with a great interest because I've >also some personal musical projects on different ARM platforms >including the RPI2 (also looking at NXP/Freescale iMX6Q, and >Rockchip RK3288). Like you Scott,

Re: [music-dsp] MIDI Synth Design Advice Please

Hi Scott, Interesting project! On 2/02/2016 2:10 AM, Scott Gravenhorst wrote: Advice regarding this endeavor would be appreciated In case you haven't found it, you should research the disable_pvt config file flag. It can reduce system jitter a little. Ross.

Re: [music-dsp] MIDI Synth Design Advice Please

Hello all, Hello Scott, I’ve followed this thread with a great interest because I’ve also some personal musical projects on different ARM platforms including the RPI2 (also looking at NXP/Freescale iMX6Q, and Rockchip RK3288). Like you Scott, these are projects to keep me busy when I’m retired

Re: [music-dsp] MIDI Synth Design Advice Please

Or for another option, I've just been checking out the new Atmel S70 series: 300 MHz, floating point, system-on-a-chip, option for Tightly-Coupled-Memory (e.g. for the per-sample-processing interrupt). It seems like it would make a wonderful low-ish cost synthesizer with excellent latency and

Re: [music-dsp] MIDI Synth Design Advice Please

Scott Gravenhorst wrote: to: Theo I saw your suggestion regarding JACK and I'm wondering "why?". ... ... Using the example program pcm.c (modified to use threads), I've been able to run the direct write loop on an isolated core and got 45 "voices" of sine production with a period size

Re: [music-dsp] MIDI Synth Design Advice Please

While not Raspberry Pi based, there's a couple microcontroller-based projects you might check out. They do pretty much exactly what you're asking and already have quite a good amount of synthesis support. Microcontrollers give you less raw computational power, but you get much easier support

Re: [music-dsp] MIDI Synth Design Advice Please

Paul Stoffregen wrote: ... First is the one I've been working on... the Teensy Audio Library. The main advantage of this way is you can integrate with almost all stuff designed for Arduino, such as the MIDI library and USB MIDI, and of course lots of hardware.

Re: [music-dsp] MIDI Synth Design Advice Please

to: Paul Stoffregen I've done quite some work with the Microchip dsPIC33FJ128. It is a microcontroller capable of 40 MIPS and it has some real DSP instructions that cause parallelism within the dsPIC. Has a built in 16 bit stereo DAC. I've been able to make a 12 voice Karplus-Strong MIDI

Re: [music-dsp] MIDI Synth Design Advice Please

About caching: modern Linuxes, apart from having access to kernel sources and making your own changes, IIRC allow for certain multiprocessing parameters to be influenced, such a locking memory ranges to threads/cores/processes. Not overly discipline thoughts about such semi pro project (I

Re: [music-dsp] MIDI Synth Design Advice Please

Thank you all for your thoughtful comments. I've read about the effects of cache on CPUs, but admittedly neglected to consider that - good to be reminded of that. As far as I have read about isolated cores, the kernel doesn't schedule anything to run on them (kernel 4.1.13), so I would

Re: [music-dsp] MIDI Synth Design Advice Please

Scott Gravenhorst wrote: I'm looking for advice regarding the design of a MIDI synthesizer. ... Advice regarding this endeavor would be appreciated. Questions include which of the transfer methods will come closest to my goal of low latency (from time to MIDI message receipt to .. Hi

Re: [music-dsp] MIDI Synth Design Advice Please

I don't have any advice, but wanted to say that this sounds like a very cool project. I hope you'll consider writing up an instructable (or something like it) to document the project. Regards, Allen On Mon, Feb 1, 2016 at 10:10 AM, Scott Gravenhorst wrote: > I'm looking

[music-dsp] MIDI Synth Design Advice Please

I'm looking for advice regarding the design of a MIDI synthesizer. In the past, I've worked with FPGAs and with dsPIC microprocessors to create successful MIDI synthesizer designs. These designs all had one thing in common: the processing consisted of code to generate a single frame (2

Re: [music-dsp] MIDI Synth Design Advice Please

apart from making sure your task is not interrupted on that core, you have to take the latencies (aka buffering) on both the MIDI input and ALSA output side into account. https://www.google.com/search?q=alsa+low+latency seems to yield some good pointers to start reading for the MIDI side, I

Re: [music-dsp] MIDI Synth Design Advice Please

Hey, Scott -- You may run into unpleasant surprises if you assume a PC processor uses deterministic time under any circumstances. Common knowledge dictates that synchronization primitives, disk access and

Re: [music-dsp] MIDI Synth Design Advice Please

On Mon, Feb 1, 2016 at 10:10 AM, Scott Gravenhorst wrote: > I've also been experimenting with threads and CPU affinity as well as > isolcpu to isolate cores. My assumption (which could be incorrect) is that > isolated cores will run at near bare metal efficiency because