~ Updates for Panako - an acoustic fingerprinting system

Panako is an acoustic fingerprinting system I developed a couple of years ago. With acoustic fingerprinting systems it is possible to find duplicates in digital music archives and compare meta-data or identify unlabelled audio fragments. In the margins of my post-doc project working with large music archives, I have found the time to update Panako significantly. The updates simplify, improve and speed up Panako.

\ Fig. General content based audio search scheme.

The main algorithms are simplified. There is also a reduction of dependencies and a refocus to core functionality. This also simplifies building the software. The retrieval characteristics are improved, mainly thanks to the use of a fine-grained Gabor transform. Also new is the near-exact hashing construct which helps with off-by-one issues when matching time bins. The key-value store used is now LMDB, which speeds up the query performance of Panako significantly. The updates should make Panako stand the test of time somewhat better.

\ Fig. The top one true positive rate for 20s query fragments. The audio playback is speed modified from 84 to 116% with respect to the indexed reference audio. The original query length is 20s, if it is slowed down by 10% it takes, evidently, 22s. Note the improvement of the 2021 version of Panako (blue) vs the 2014 version (light-gray). As a baseline the standard algorithm (wang 2003) is included as well. For the 2021 Panako algorithm, audio recognition performance suffers (below 80) when playback speed is changed more than 10.

A more complete list of updates can be found below and on the Panako GitHub repository:

- The number of dependencies has been drastically cut by removing support for multiple key-value stores. - The key-value store has been changed to a faster and simpler system (from [MapDB](https://mapdb.org) to [LMDB](http://www.lmdb.tech/doc)). - The SyncSink functionality has been moved to another project (with Panako as dependency). - The main algorithms have been replaced with simpler and better working versions: - Olaf is a new implementation of the classic Shazam algorithm. - The algoritm described in the Panako paper was also replaced. The core ideas are still the same. The main change is the use of a [Gabor transform](https://en.wikipedia.org/wiki/Gabor_transform) to go from time domain to the spectral domain (previously a constant-q transform was used). The gabor transform is implemented by [JGaborator](https://github.com/JorenSix/JGaborator) which in turn relies on [The Gaborator](https://gaborator.com/) C library via JNI. - Folder structure has been simplified. - The UI which was mainly used for debugging has been removed. - A new set of helper scripts are added in the `scripts` directory. They help with evaluation, parsing results, checking results, building panako, creating documentation,... - Changed the default panako location to \~/.panako, so users can install and use panako more easily (without need for sudo rights)

Fig: An interactive CLI session with Panako.

Code and UGent