[sdiy] Hardware convolution box?

[Mikko Helin]

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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>>
>>
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