Example audio fingerprint server using Chromaprint

server.py

import chromaprint
from flask import Flask, request, jsonify


SQL_TABLES = """

CREATE TABLE IF NOT EXISTS fingerprint
(
    id INTEGER PRIMARY KEY,
    fingerprint TEXT NOT NULL
);

CREATE TABLE IF NOT EXISTS fingerprint_meta
(
    fingerprint_id NOT NULL REFERENCES fingerprint (id) ON DELETE CASCADE,
    name TEXT NOT NULL,
    value TEXT NOT NULL,
    PRIMARY KEY (fingerprint_id, name)
);

CREATE TABLE IF NOT EXISTS fingerprint_index
(
    fingerprint_id NOT NULL REFERENCES fingerprint (id) ON DELETE CASCADE,
    hash INTEGER NOT NULL,
    PRIMARY KEY (fingerprint_id, name)
);

CREATE INDEX IF NOT EXISTS fingerprint_index_idx_hash ON fingerprint_index (hash);

"""


class Server(object):

    def __init__(self):
        self.db = None

    def prepare(self):
        if self.db is not None:
            return
        self.db = sqlite3.connect('fingerprints.db')
        self.db.executescript(SQL_TABLES)

    def reset(self):
        self.db.execute("DELETE FROM fingerprint_hash")
        self.db.execute("DELETE FROM fingerprint_meta")
        self.db.execute("DELETE FROM fingerprint")

    def submit(self, fingerprint, meta):
        fingerprint_version, raw_fingerprint = chromaprint.decode_fingerprint(fingerprint)
        cursor = self.db.cursor()
        cursor.execute("INSERT INTO fingerprint (fingerprint) VALUES (?)", (fingerprint,))
        fingerprint_id = cursor.lastrowid
        cursor.executemany("INSERT INTO fingerprint_index (fingerprint_id, hash) VALUES (?, ?)",
            ((fingerprint_id, hash) for hash in raw_fingerprint))
        cursor.executemany("INSERT INTO fingerprint_meta (fingerprint_id, name, value) VALUES (?, ?, ?)",
            ((fingerprint_id, name, value) for name, value in meta.iteritems()))

    def lookup(self):
        fingerprint_version, raw_fingerprint = chromaprint.decode_fingerprint(fingerprint)
        cursor = self.db.cursor()
        cursor.execute("""
            SELECT fingerprint_id, count(*) FROM fingerprint_index
            WHERE hash IN (""" + ",".join((str(hash) for hash in raw_fingerprint)) + """)
            GROUP BY fingerprint_id
        """)
        candidates = dict((row[0], row[1]) for row in cursor)
        return candidates


app = Flask(__name__)

server = Server()
server.prepare()


app.route('/reset')
def reset()
    with server.db:
        server.reset()
    return jsonify({'status': 'ok'})


app.route('/submit')
def submit():
    fingerprint = request.args['fingerprint']
    with server.db:
        pass
    return jsonify({'status': 'ok'})


app.route('/lookup')
def lookup()
    fingerprint = request.args['fingerprint']
    return jsonify(server.lookup(fingerprint))


if __name__ == '__main__':
    app.run()