pylastfp

pylastfp is a Python interface to Last.fm's acoustic fingerprinting library (called fplib) and its related API services. It performs fingerprint extraction, fingerprint ID lookup, and track metadata lookup. It also comes with some helpers for decoding audio files.

Installation

To install, you will need a compiler and the dependencies required by fplib itself: fftw (compiled for single-precision floats) and libsamplerate.

Once you have these, you can easily install from PyPI using pip:

pip install pylastfp

Or, if you don't have pip (or easy_install), head to the download page. The normal install command should work:

python setup.py install

To build from the version control source (i.e., not from a release tarball), you will also need Cython. (The source distributions include the generated C++ file, avoiding the need for Cython. This package's setup.py plays tricks to detect whether you have Cython installed.)

Running

You can run the included fingerprinter/lookup script, lastmatch.py, to test your installation:

 lastmatch.py mysterious_music.mp3

This will show metadata matches from Last.fm's database. The script uses Gstreamer's Python bindings to decode MP3s. You can also use pymad instead of Gstreamer (for MPEG audio only) by supplying the -m flag:

 lastmatch.py -m mysterious_music.mp3

Using in Your Code

The script exhibits the usual way to use pylastfp, which is this:

>>> import lastfp
>>> xml = lastfp.gst_match(apikey, path)
>>> matches = lastfp.parse_metadata(xml)
>>> print matches[0]['artist'], '-', matches[0]['title']
The National - Fake Emprire

This example uses the gst_match convenience function, which uses Gstreamer to decode audio data. The function imports the Gstreamer module when called, so if you don't want to depend on Gstreamer, just don't call this function. Another similar function called mad_match instead imports the pymad library and uses MAD to decode instead of Gstreamer.

If you have your own way of decoding audio, you can use the lower-level interface:

>>> xml = lastfp.match(apikey, pcmdata, samplerate, time_in_secs)

Of course, you'll need a PCM stream for the audio you want to fingerprint. The pcmdata parameter must be an iterable of Python str or buffer objects containing PCM data as arrays of C short (16-bit integer) values.

All of these functions (match, gst_match, and mad_match) accept an additional optional parameter called metadata. It should be a dict containing your current guess at the file's metadata. Last.fm might use this information to improve their database. The dict should use these keys (all of which are optional): "artist", "album", and "track".

The module internally performs thread-safe API limiting to 5 queries per second, in accordance with Last.fm's API TOS.

What is new in this release:

• Use audioread instead of the included pygst and pymad decoders.

What is new in version 0.5:

• Handle empty responses from the API. setup.py now searches the Homebrew user-local prefix.

What is new in version 0.4:

• Fix cleanup bug in gstdec that was causing files to remain open.

What is new in version 0.3:

• Fix typo in handling of HTTP errors. Handle cases when HTTP status line is malformed

What is new in version 0.2:

• Fix a horrible memory leak. Fail safely when file is too short. Safely handle malformed XML returned from the API. Handle and expose HTTP failures.

Requirements:

• Python