[sdiy] Hardware convolution box?

[cheater00 cheater00]

Coincidentally I have found this really simple and concise definition of
the FFT today:

https://www.reddit.com/r/Python/comments/1la4jp/understanding_the_fft_algorithm_with_python/

On Sat, 11 Feb 2017 11:30 Mikko Helin, <maohelin at gmail.com> wrote:

> Forgot to mention the method is called non-uniform partitioned
> concolution, the paper can be found here:
> http://www.cs.ust.hk/mjg_lib/bibs/DPSu/DPSu.Files/Ga95.PDF
>
>
> On Sat, Feb 11, 2017 at 12:27 PM, Mikko Helin <maohelin at gmail.com> wrote:
> > Proper way to handle large filter kernels (IR's) is to use partitioned
> > kenel and various combined methods (FIR for initial response, FFT for
> > larger delayed partitions) to get lower overall latency, see the
> > answer to this questin on StackExchange forum:
> >
> >
> http://dsp.stackexchange.com/questions/25931/how-do-real-time-convolution-plugins-process-audio-so-quickly
> >
> > So your hardware should be built around this in mind. For two second
> > IR (mono) youll need at least (sampling at 48 kHz) 192 kbytes of RAM
> > (not necessary continuous). It can be done easily by the board Mark
> > Seel is going to put to Kickstarter soon. It uses XF232 XMOS chip with
> > 32 cores and total of 1024 kbytes or RAM. Please to to forum and ask
> > any question there. One of the main uses for the board is going to be
> > guitar speaker simulation using IR:s (in addition to any other
> > conventional stompbox functions).
> >
> > http://www.diystompboxes.com/smfforum/index.php?topic=114354.120
> >
> > On Fri, Feb 10, 2017 at 10:27 PM, cheater00 cheater00
> > <cheater00 at gmail.com> wrote:
> >> I assumed as much - that's why I think a convolution box should be
> within
> >> reach of even a novice dev. What about libraries for: reading off sd
> card or
> >> usb stick; using data structures like ring buffers; driving lcds; text
> >> driven menu uis; scanning front panels... is this sort of stuff
> available?
> >>
> >>
> >> On Fri, 10 Feb 2017 19:56 , <rsdio at audiobanshee.com> wrote:
> >>>
> >>> Hello all,
> >>>
> >>> Note that Texas Instruments has open source libraries that include most
> >>> common DSP routines. These libraries are almost exclusively written in
> >>> assembly, but the routines can be called from Standard C code. It's
> possible
> >>> to write firmware mostly in C, while linking in assembly routines
> written by
> >>> the experts at TI. When developing for the TMS320 C5000 family, I
> looked at
> >>> how the different variations of FFT were optimized for different goals
> and
> >>> applications, and then designed my own hybrid FFT that was optimized
> for my
> >>> exact data. Because the libraries are open source, I was able to
> contribute
> >>> bug fixes and optimizations to the Texas Instruments library that
> should now
> >>> be available to other developers on the C5000 family.
> >>>
> >>> I assume that the C6000 family has similar open source libraries. In
> other
> >>> words, you might not have to learn TMS320 assembly to get optimal
> code. I
> >>> haven't checked, but it's possible that convolution is already
> available in
> >>> the library. You might benefit from tweaking their code, but as a
> starting
> >>> point you might be able to get up and running quickly with a DSP
> library.
> >>>
> >>> Brian
> >>>
> >>>
> >>> On Feb 10, 2017, at 8:43 AM, Terry Shultz <thx1138 at earthlink.net>
> wrote:
> >>>
> >>> I use the Code Composer tools from TI and I have been using these tools
> >>> since they were in Alpha state.
> >>> Assembly code is difficult on the TI DSP Sitara platform. Pipeline
> length
> >>> and such.
> >>>
> >>> I find it easier to use one DSP as the Decoder for Atmos and the 2nd as
> >>> post processing and Bass manager etc.
> >>>
> >>> Also found it easier to do assembly programming on the ADI 4th
> Generation
> >>> Falcon parts as the pipeline line was a bit shorter. The longer the
> >>> pipeline,
> >>> the more difficult to re-order efficiently.
> >>>
> >>> In some cases I have had to build a small library for hand tuned FFT’s
> and
> >>> IFFT’s. Can’t show this IP as I was paid to develop for Automotive
> apps. by
> >>> Semiconductor company.
> >>>
> >>> The compilers have gotten pretty good for TI and ADI and I do less
> >>> assembly work more and more.
> >>>
> >>>
> >>> _______________________________________________
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> >>> Synth-diy at synth-diy.org
> >>> http://synth-diy.org/mailman/listinfo/synth-diy
> >>
> >>
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> >>
>
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