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.