File indexing completed on 2024-05-19 04:56:25

 /**
  * \file fingerprintcalculator.h
  * Chromaprint fingerprint calculator.
  *
  * \b Project: Kid3
  * \author Urs Fleisch
  * \date 21 Jan 2012
  *
  * Copyright (C) 2012-2024  Urs Fleisch
  *
  * This file is part of Kid3.
  *
  * Kid3 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 2 of the License, or
  * (at your option) any later version.
  *
  * Kid3 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 this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
 #pragma once
 
 #include <QObject>
 #include <QString>
 #include <chromaprint.h>
 
 class AbstractFingerprintDecoder;
 
 /**
  * Calculate Chromaprint audio fingerprints for audio files.
  */
 class FingerprintCalculator : public QObject {
   Q_OBJECT
 public:
   /** Types of error occurring in fingerprint calculation. */
   enum Error {
     Ok,               /**< Fingerprint calculation OK */
     Pending,          /**< Not started */
     NoStreamFound,    /**< Format not recognized or no audio stream found */
     NoCodecFound,     /**< No codec found */
     NoConverterFound, /**< Sample rate conversion failed or unavailable */
     FingerprintCalculationFailed, /**< Chromaprint error */
     Timeout,          /**< Operation timeout */
     DecoderError      /**< Error while decoding */
   };
 
   /**
    * Constructor.
    */
   explicit FingerprintCalculator(QObject* parent = nullptr);
 
   /**
    * Destructor.
    */
   ~FingerprintCalculator() override;
 
   /**
    * Calculate audio fingerprint for audio file.
    * When the calculation is finished, finished() is emitted.
    *
    * @param fileName path to audio file
    */
   void start(const QString& fileName);
 
   /**
    * Stop decoder.
    */
   void stop();
 
 signals:
   /**
    * Emitted when the fingerprint calculation is finished.
    *
    * @param fingerprint Chromaprint fingerprint
    * @param duration duration in seconds
    * @param error error code, enum FingerprintCalculator::Error
    */
   void finished(const QString& fingerprint, int duration, int error);
 
 private slots:
   /**
    * Called when decoding starts.
    * @param sampleRate sample rate of the audio stream (in Hz)
    * @param channelCount numbers of channels in the audio stream (1 or 2)
    */
   void startChromaprint(int sampleRate, int channelCount);
 
   /**
    * Called when decoded data is available.
    * @param data 16-bit signed integers in native byte-order
    */
   void feedChromaprint(QByteArray data);
 
   /**
    * Called when an error occurs.
    * @param err error code, enum FingerprintCalculator::Error
    */
   void receiveError(int err);
 
   /**
    * Called when decoding finished successfully.
    * @param duration duration of stream in seconds
    */
   void finishChromaprint(int duration);
 
 private:
   ChromaprintContext* m_chromaprintCtx;
   AbstractFingerprintDecoder* m_decoder;
 };