jurihock / qdft Goto Github PK
View Code? Open in Web Editor NEWConstant-Q Sliding DFT in C++, Rust and Python
License: MIT License
Constant-Q Sliding DFT in C++, Rust and Python
License: MIT License
as implemented in jurihock/sdft
(see also jurihock/sdft#5)
see also Fast, Accurate Frequency Estimators
As mentioned in my comment, the std::rotate
is most likely a major performance issue.
Actually there is no measurable difference between the following variations:
std::rotate(inputs.begin(), inputs.begin() + 1, inputs.end());
std::copy(inputs.begin() + 1, inputs.end(), inputs.begin());
std::shift_left(inputs.begin(), inputs.end(), 1);
But instead of std::vector
use std::deque
to shift the buffered values like so:
inputs.pop_front();
inputs.push_back(sample);
The complexity of the linear/random element access as well as insertion or removal of elements at both ends of the std::deque
should be still O(1).
Variable-Q transform is very similar to constant-Q transform except the Q value is lower as the frequency decreases, which is useful if you want to have better time resolution on lower frequencies at the expense of frequency resolution at bass frequencies (like a logarithmic-frequency spectrogram with ERB frequency resolution).
Arbitrary frequency scale for bin spacing also enables variable-Q transform and with that, it can directly calculate Mel spectrogram using VQT with Mel-frequency bin spacing and resolution.
Just do it and publish on crates.io
It is worth noting that asymmetric window functions are impossible to implement, not even the window skew parameter outlined in my collection of audio analysis functions on a sliding DFT, but what you can do is make the sDFT an IIR filter bank (which is a damped sine wave). which uses less RAM (since it doesn't need ring buffers) and it can be cascaded (just like biquad filters) to achieve a steeper rolloff at the cost of greater delay (thus, bad time resolution) on long window sizes
qdft
A declarative, efficient, and flexible JavaScript library for building user interfaces.
๐ Vue.js is a progressive, incrementally-adoptable JavaScript framework for building UI on the web.
TypeScript is a superset of JavaScript that compiles to clean JavaScript output.
An Open Source Machine Learning Framework for Everyone
The Web framework for perfectionists with deadlines.
A PHP framework for web artisans
Bring data to life with SVG, Canvas and HTML. ๐๐๐
JavaScript (JS) is a lightweight interpreted programming language with first-class functions.
Some thing interesting about web. New door for the world.
A server is a program made to process requests and deliver data to clients.
Machine learning is a way of modeling and interpreting data that allows a piece of software to respond intelligently.
Some thing interesting about visualization, use data art
Some thing interesting about game, make everyone happy.
We are working to build community through open source technology. NB: members must have two-factor auth.
Open source projects and samples from Microsoft.
Google โค๏ธ Open Source for everyone.
Alibaba Open Source for everyone
Data-Driven Documents codes.
China tencent open source team.