File indexing completed on 2024-05-12 04:55:35

 /**
  * \file fingerprintcalculator.cpp
  * Chromaprint fingerprint calculator.
  *
  * \b Project: Kid3
  * \author Urs Fleisch
  * \date 21 Jan 2012
  *
  * Copyright (C) 2012-2018  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/>.
  */
 
 #define __STDC_CONSTANT_MACROS
 #include "fingerprintcalculator.h"
 #include "config.h"
 #include "abstractfingerprintdecoder.h"
 
 /**
  * Constructor.
  */
 FingerprintCalculator::FingerprintCalculator(QObject* parent) : QObject(parent),
   m_chromaprintCtx(nullptr),
   m_decoder(AbstractFingerprintDecoder::createFingerprintDecoder(this))
 {
   connect(m_decoder, &AbstractFingerprintDecoder::started,
           this, &FingerprintCalculator::startChromaprint);
   connect(m_decoder, &AbstractFingerprintDecoder::bufferReady,
           this, &FingerprintCalculator::feedChromaprint);
   connect(m_decoder, &AbstractFingerprintDecoder::error,
           this, &FingerprintCalculator::receiveError);
   connect(m_decoder, &AbstractFingerprintDecoder::finished,
           this, &FingerprintCalculator::finishChromaprint);
 }
 
 /**
  * Destructor.
  */
 FingerprintCalculator::~FingerprintCalculator()
 {
   if (m_chromaprintCtx) {
     ::chromaprint_free(m_chromaprintCtx);
   }
 }
 
 /**
  * Calculate audio fingerprint for audio file.
  * When the calculation is finished, finished() is emitted.
  *
  * @param fileName path to audio file
  */
 void FingerprintCalculator::start(const QString& fileName) {
   if (!m_chromaprintCtx) {
     // Lazy initialization to save resources if not used
     m_chromaprintCtx = ::chromaprint_new(CHROMAPRINT_ALGORITHM_DEFAULT);
   }
   m_decoder->start(fileName);
 }
 
 /**
  * Stop decoder.
  */
 void FingerprintCalculator::stop() {
   m_decoder->stop();
 }
 
 /**
  * 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 FingerprintCalculator::startChromaprint(int sampleRate, int channelCount)
 {
   ::chromaprint_start(m_chromaprintCtx, sampleRate, channelCount);
 }
 
 /**
  * Called when decoded data is available.
  * @param data 16-bit signed integers in native byte-order
  */
 void FingerprintCalculator::feedChromaprint(QByteArray data)
 {
   if (!::chromaprint_feed(m_chromaprintCtx,
                           reinterpret_cast<qint16*>(data.data()),
                           data.size() / 2)) {
     m_decoder->stop();
     emit finished(QString(), 0, FingerprintCalculationFailed);
   }
 }
 
 /**
  * Called when an error occurs.
  * @param err error code, enum FingerprintCalculator::Error
  */
 void FingerprintCalculator::receiveError(int err)
 {
   emit finished(QString(), 0, err);
 }
 
 /**
  * Called when decoding finished successfully.
  * @param duration duration of stream in seconds
  */
 void FingerprintCalculator::finishChromaprint(int duration)
 {
   int err = Ok;
   QString fingerprint;
   char* fp;
   if (::chromaprint_finish(m_chromaprintCtx) &&
       ::chromaprint_get_fingerprint(m_chromaprintCtx, &fp)) {
     fingerprint = QString::fromLatin1(fp);
     ::chromaprint_dealloc(fp);
   } else {
     err = FingerprintCalculationFailed;
   }
   emit finished(fingerprint, duration, err);
 }