Understand Dejavu performance and accuracy
masterDejavu is an audio fingerprinting system designed for speed and accuracy. Performance characteristics include:
- Accuracy: High recall even with short audio segments. Testing showed ~60% accuracy with 1 second of audio, ~96% with 2 seconds, and 100% with 5+ seconds. Accuracy remains stable even with compressed streams (e.g., Spotify 160 kbit/s) and environmental noise.
- Speed: Matching speed is roughly linear relative to the recording time. On tested hardware, matching occurs at approximately 3x listening speed. The bottleneck is the peak finding process, which is single-threaded in the Python implementation.
- Storage: Fingerprint storage scales with the number of fingerprints generated. For 45 songs, 5.4 million fingerprints occupied 377 MB.
Note on Latency: Total time to match includes recording time and the Round Trip Time (RTT) to the MySQL database. While RTT adds to the constant overhead, it does not affect the core matching process speed.