Chromaprint and its associated Acoustid Web service make up a high-quality, open-source acoustic fingerprinting system. pyacoustid provides Python bindings for both the fingerprinting algorithm library, which is written in C but portable, and the Web service, which provides fingerprint lookups.
First, install the Chromaprint fingerprinting library by Lukas Lalinsky. (The library itself depends on an FFT library, but it's smart enough to use an algorithm from software you probably already have installed; see the Chromaprint page for details.)
Then you can install this library from PyPI using pip:
pip install pyacoustid
This library uses audioread to do audio decoding (pip should automatically install this dependency), but it's not really necessary if you already have decoded audio.
You can run the included demonstration script, aidmatch.py, to test your installation:
python aidmatch.py mysterious_music.mp3
This will show the top metadata match from Acoustid's database. The script uses audioread to decode music, so it should transparently use a media library available on your system (GStreamer, FFmpeg, MAD, or Core Audio).
Using in Your Code
The simplest way to use pyacoustid to identify audio files is to call the match function:
>>> import acoustid
>>> score, recording_id, title, artist = acoustid.match(apikey, path)
This convenience function uses audioread to decode audio and parses the response for you, pulling out the most important track metadata. Everything happens in one fell swoop. There are also a number of "smaller" functions you can use to perform parts of the process:
- fingerprint(samplerate, channels, pcmiter): Generate a fingerprint for raw audio data. Specify the audio parameters and give an iterable containing blocks of PCM data.
- lookup(apikey, fingerprint, duration): Make a request to the Acoustid API to look up the fingerprint returned by the previous function. An API key is required, as is the length, in seconds, of the source audio. Returns a parsed JSON response.
- parse_lookup_result(data): Given a parsed JSON response, return a tuple containing the match score (a float between 0 and 1), the MusicBrainz recording ID, title, and artist name of the top match.
The module internally performs thread-safe API rate limiting to 3 queries per second whenever the Web API is called, in accordance with the Web service documentation.
Calls to the library can raise AcoustidError exceptions of two subtypes: FingerprintGenerationError and WebServiceError. Catch these exceptions if you want to proceed when audio can't be decoded or no match is found on the server.
- Properly encode Unicode parameters (resolves a UnicodeEncodeError in fingerprint submission). Parse all recordings for each Acoustid lookup result.