strawberry-audio-player-windows-mac-linux/src/engine/chromaprinter.h

/*
 * Strawberry Music Player
 * This file was part of Clementine.
 * Copyright 2012, David Sansome <me@davidsansome.com>
 * Copyright 2019-2021, Jonas Kvinge <jonas@jkvinge.net>
 *
 * Strawberry is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * Strawberry is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with Strawberry.  If not, see <http://www.gnu.org/licenses/>.
 *
 */

#ifndef CHROMAPRINTER_H
#define CHROMAPRINTER_H

#include "config.h"

#include <glib.h>
#include <gst/gst.h>
#include <gst/app/gstappsink.h>

#include <QBuffer>
#include <QString>

class Chromaprinter {
  // Creates a Chromaprint fingerprint from a song.
  // Uses GStreamer to open and decode the file as PCM data and passes this to Chromaprint's code generator.
  // The generated code can be used to identify a song via Acoustid.
  // You should create one Chromaprinter for each file you want to fingerprint.
  // This class works well with QtConcurrentMap.

 public:
  explicit Chromaprinter(const QString &filename);

  // Creates a fingerprint from the song.
  // This method is blocking, so you want to call it in another thread.
  // Returns an empty string if no fingerprint could be created.
  QString CreateFingerprint();

 private:
  static GstElement *CreateElement(const QString &factory_name, GstElement *bin = nullptr);

  static void NewPadCallback(GstElement *element, GstPad *pad, gpointer data);
  static GstFlowReturn NewBufferCallback(GstAppSink *app_sink, gpointer self);

 private:
  QString filename_;

  GstElement *convert_element_;

  QBuffer buffer_;
};

#endif  // CHROMAPRINTER_H