multirate processing?

Hello Rolf,

The change was a framework change in SigmaStudio to allow for the development of multi-rate signal flow. The rest of the cells to do multi-rate signal flow are still in development. So at the moment this feature is not ready.

What are the details of your application? What will the data rates be?

Dave T

Hi Dave,

my idea is to perform the convolution of audio signals with very long filters (typically ~65.000 taps@48kHz) in the wavelet domain.

This basically means splitting the audio in a number of frequency bands, each one lower by a factor of 2 on center frequency and samplerate then the previous. The FIR filter also given in this representation, the filtering is done bandwise. At the end recombining the filtered bands.

The reason for this crazy sounding process are is in the nature of my typical filters (room response equalizing). In the time domain the lower bands are long, the higher bands are short, in the wavelet domain they require nearley the same number of taps. And in the sum this is much much less then directly filtering in the time domain.

If would be helpful for a rough implementation if one instance of a algorithm could have switchable alternative sets of parameters. For example a ~30 tap fir filter with 8..16 coeffizent sets - the right one would be selected each time a sample arrives ... a really efficient implementation (e.g. wavlet lifting scheme) probably requires direct acces to the core.

This is a pure hobbyist project. If somebody like the idea, feel free to use it.

Thank you for the attention, Dave

Rolf

Hello Rolf,

Which processor are you using? If you are not using the ADAU1452 then you should try it. The quad core architecture makes it able to process four taps of an FIR filter in one clock period. It is screaming! Plus, these parts have more memory.

Dave T

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EZ Admin