reverb
As a music fan, I always wanted to implement my own reverb. Here it is - experimental as usual :P. It is a basic variant of the Jot's FDN Late Reverberator using a Hadamard matrix as feedback matrix. Depending on how you choose the parameters and matrix order, you can get a decent reverb out of it. But if you have any ideas for an even better result, feel free to contribute.
Parameters
pattern: [param name] ([label in schematic]) // [description]
feedDryIn (b) // amount of dry signal that is fed into the delay lines (>= 0)
feedDryOut (c) // amount of wet signal that is fed back into the main line (>= 0)
drySignalMix (d) // amount of dry signal that is fed into the main line (>= 0)
delayTapTime (M) // the maximum delay tap time in ms (> 0)
decay (g) // amount of decay of the delay lines (>= 0 && < 1)
Components
- CircularBuffer - cyclic array implementation used as buffer
- Reverb - main part doing the algorithm work and holding all parameters
- MultiChannelReverb - helper class to create and manage multiple reverb instances at once (e.g. for stereo application)
Fun stuff
One day, I came up with the idea of putting a video through the reverberator. With OpenCV, it is easy (in C++ ^^) to extract the pixels of all frames of a video and so, the raw numbers are treated as an ordinary audio signal. Experimenting a bit with the parameters, it gets a "trippy" experience. A demo usage can be found in the 'video' branch. Get creative too - I'm looking forward for more things being reverbed :D. Youtube
Building
// make sure to have cmake and libsndfile (if you want to use the demo main.cpp) installed
// on Mac, this can be simply done via Homebrew: brew install cmake libsndfile
git clone https://github.com/DeerMichel/reverb/
cd reverb
mkdir bin
cd bin
cmake ..
make
cp ../misc/input.wav . // or use your own audio file
./ReverbMain
afplay output.wav // or equivalent
For a sample usage, take a look at the main.cpp.
Missing features
- Better control over all parameters (to achieve a nicer overall sound)
- Spreading multichannel reverb
- Consistent DAW plugin integration (or a GUI at all)
- Tests (right, just kidding)
- And much more... sure...
Third-party
- libsndfile (LGPL) - optional, only used in demo main.cpp
- OpenCV (BSD) - optional, only used in video demo main.cpp
ps: input.wav is a quick and dirty production by myself - no need to worry about licensing as long as it is used in the context of this project.