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CMSIS DSP is a great tool which allows Cortex-M4 devices to have a great app field range, even replacing some general purpose DSP sometimes. However I am missing some "simple" new functions that could enhance, even more, the use of it.
- LOG approximation functions (float, int16, etc), which are one of the greatest time consumption methods in an Audio application.
- Vector Division, as Vector Multiplication (arm_mult_f32), quite handy.
- Threshold functions, something similar to the arm_max_f32 function. Comparing athreshold level and returning a vector with ones or zeroes if the original vector is bigger or smaller than the threshold level.
- Complex Phase calculation, same way as arm_cmplx_mag_f32 does for calculating the magnitude of an output FFT signal, but for getting the phase of two signals.
I am sure many other users have many more suggestions/ideas to extend the functionality of CMSIS DSP, which is the base of many great prodcuts/applications out there.
Please, take this as just a starting point, but from my point of view, I think this could be pretty interesting.
Hi and thanks for the input regarding the CMSIS functions. We'll keep these in mind as we discuss new features for upcoming releases of the library.
If anyone else has suggestions for additional functions, please let us know!
Hello Dr. Beckman.
How is the upcoming release going? Will we see any of these changes included?
There is no near term update to the CMSIS library planned. The earliest something would happen is mid next year.
Note that the library already contains convolution, correlation, polyphase FIR interpolation and decimation. Would these work for you?
Thank you Dr. Beckman.
You are right, I forgot convolution is already there. We are already using FIR.
However, I am missing LOG, Exponential, Thresholds, Phase calculation, Vector divisions and Complex vector constructors. I think these can save quite a processing time if implemented in CMSIS.
Don't you agree?
Actually I was asking about your view with this proposal.
Just a question about the additional functions. The math.h library is already fairly well optimized. It is possible to get a speed boost for functions like log() and exp() if you operate on a vector of values and if an approximation is OK. Could you live with less precision than math.h or do you need full precision? If you need full precision then you should stick with math.h.
Less precision is OK for me. I expected that.
In fact, I am using some approximation functions for converting to log10f() values, but they work slower than on PCs. Probably architechture?
Thank you pbeckmann