Chromaprint and its associated Acoustid Web service make up a
high-quality, open-source acoustic fingerprinting system. This package provides
Python bindings for both the fingerprinting algorithm library, which is written
in C but portable, and the Web service, which provides fingerprint lookups.
Installation
This library works with Python 2 (2.7+, possibly also 2.6) and Python 3
(3.3+).
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.) This module can use either the Chromaprint dynamic library or
the fpcalc command-line tool, which itself depends on libavcodec. If you
use fpcalc, either ensure that it is on your $PATH or set the FPCALC
environment variable to its location.
Then you can install this library from PyPI using pip:
$ pip install pyacoustid
This library uses audioread to do audio decoding when not using fpcalc
and requests to talk to the HTTP API (pip should automatically install
these dependencies).
Running
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
>>> for score, recording_id, title, artist in 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. It returns in
iterable over tuples of relevant information. 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.
fingerprint_file(path): Using either the Chromaprint dynamic library or
the fpcalc command-line tool, fingerprint an audio file. (You can use
force_fpcalc to use only the latter.) Returns a pair consisting of the
file’s duration and its fingerprint.
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 an
iterator over tuples containing the match score (a float between 0 and 1), the
MusicBrainz recording ID, title, and artist name for each match.
compare_fingerprints(a, b): Compare two fingerprints produced by
fingerprint_file, returning a similarity score.
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.
If you’re running your own Acoustid database server, you can set the base URL
for all API calls with the set_base_url function.
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. NoBackendError, a subclass of FingerprintGenerationError, is
used when the Chromaprint library or fpcalc command-line tool cannot be found.
Version History
1.3.0
Multiple artists are joined by join phrases, as displayed on the web page.
A new (pure-Python) function compares two Chromaprint fingerprints for
similarity.
Search more shared-library locations for the Chromaprint library on Windows.
1.2.3
Fix the signedness of numbers returned from
chromaprint_decode_fingerprint.
1.2.2
Fix a regression in the previous version that caused a KeyError crash when
calling submit.
1.2.1
The meta parameter to some API functions can now be a list (instead of
just a single string).
1.2.0
Add a force_fpcalc option to fingerprint_file and match.
Avoid leaving a dangling socket after communicating with the server.
Fix a crash when passing a memoryview object to the fingerprinter.
API requests can now optionally time out.
More reliably find the library on Windows on Python 3.8.
Add a hash_fingerprint function to the low-level library.
1.1.7
Include a LICENSE file.
1.1.6
In submission, avoid an error on non-integer durations.
A new function, get_submission_status, abstracts the API endpoint for
monitoring submissions using the (new) result from the submit function.
1.1.5
Fix compatibility with Python 3 in the submit function.
Errors in submit are now also handled correctly (i.e., they raise an
informative WebServiceError instead of a TypeError).
1.1.4
Fix an error on versions of the fpcalc tool that report the duration as a
fractional number.
1.1.3
Accept bytearray objects in addition to other bytes-like types.
1.1.2
Fix a possible crash on Unicode text in Python 2 in a non-Unicode locale.
Look for version “1” of the Chromaprint shared library file.
1.1.1
Fix a possible setup error on Python 3 (thanks to Simon Chopin).
1.1.0
Include fpcalc.py script in source distributions.
Add Python 3 support (thanks to Igor Tsarev).
1.0.0
Include fpcalc.py, a script mimicking the fpcalc program from the
Chromaprint package.
Handle a UnicodeDecodeError raised when using the fpcalc backend on
Windows with Unicode filenames.
Standard error output from fpcalc is suppressed.
0.7
Properly encode Unicode parameters (resolves a UnicodeEncodeError
in fingerprint submission).
Parse all recordings for each Acoustid lookup result.
0.6
Add a new function, fingerprint_file, that automatically selects a
backend for fingerprinting a single file.
0.5
Fix response parsing when recording has no artists or title.
Fix compatibility with Python < 2.7.
Add specific NoBackendError exception.
0.4
Fingerprinting can now fall back to using the fpcalc command-line tool
instead of the Chromaprint dynamic library so the library can be used with
the binary distributions (thanks to Lukas Lalinsky).
Fingerprint submission (thanks to Alastair Porter).
Data chunks can now be buffers as well as bytestrings (fixes compatibility
with pymad).
0.3
Configurable API base URL.
Result parser now generates all results instead of returning just one.
Find the chromaprint library on Cygwin.
New module names: chromaprint and acoustid (no package).
0.2
Compress HTTP requests and responses.
Limit audio decoding to 120 seconds.
Return score from convenience function.
0.1
Initial release.
Credits
This library is by Adrian Sampson. Chromaprint and Acoustid are by Lukas
Lalinsky. This package includes the original ctypes-based bindings
written by Lukas. The entire library is made available under the MIT license.
pyacoustid was written to be used with beets, which you should probably check
out.