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

 /**
  * \file qtfingerprintdecoder.cpp
  * Chromaprint fingerprint decoder using QAudioDecoder.
  *
  * \b Project: Kid3
  * \author Urs Fleisch
  * \date 15 Feb 2013
  *
  * Copyright (C) 2013  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/>.
  */
 
 #include "qtfingerprintdecoder.h"
 #include <QAudioDecoder>
 #include <QTimer>
 #if QT_VERSION >= 0x060200
 #include <QUrl>
 #endif
 #include "fingerprintcalculator.h"
 
 /**
  * Constructor.
  * @param parent parent object
  */
 QtFingerprintDecoder::QtFingerprintDecoder(QObject* parent) :
   AbstractFingerprintDecoder(parent),
   m_decoder(new QAudioDecoder(this)), m_timer(new QTimer(this))
 {
   QAudioFormat desiredFormat;
   desiredFormat.setChannelCount(2);
   desiredFormat.setSampleRate(44100);
 #if QT_VERSION >= 0x060200
   desiredFormat.setSampleFormat(QAudioFormat::Int16);
 #else
   desiredFormat.setCodec(QLatin1String("audio/x-raw-int"));
   desiredFormat.setSampleType(QAudioFormat::SignedInt);
   desiredFormat.setSampleSize(16);
 #endif
 
   m_decoder->setAudioFormat(desiredFormat);
   connect(m_decoder, SIGNAL(bufferReady()), this, SLOT(receiveBuffer()));
   connect(m_decoder, SIGNAL(error(QAudioDecoder::Error)),
           this, SLOT(receiveError()));
   connect(m_decoder, SIGNAL(finished()), this, SLOT(finishDecoding()));
 
   m_timer->setSingleShot(true);
   m_timer->setInterval(5000);
   connect(m_timer, SIGNAL(timeout()), this, SLOT(receiveTimeout()));
 }
 
 /**
  * Destructor.
  */
 QtFingerprintDecoder::~QtFingerprintDecoder()
 {
 }
 
 /**
  * Run decoder on audio file.
  * @param filePath path to audio file
  */
 void QtFingerprintDecoder::start(const QString& filePath)
 {
   AbstractFingerprintDecoder::start(filePath);
 #if QT_VERSION >= 0x060200
   m_decoder->setSource(QUrl::fromLocalFile(filePath));
 #else
   m_decoder->setSourceFilename(filePath);
 #endif
 
   QAudioFormat format = m_decoder->audioFormat();
   emit started(format.sampleRate(), format.channelCount());
   m_timer->start();
   m_decoder->start();
 }
 
 /**
  * Stop decoder.
  * Can be used to stop the decoder when an error is found after
  * getting bufferReady() data.
  */
 void QtFingerprintDecoder::stop()
 {
   AbstractFingerprintDecoder::stop();
   m_timer->stop();
   m_decoder->stop();
 }
 
 /**
  * Receive a buffer with decoded audio data.
  */
 void QtFingerprintDecoder::receiveBuffer()
 {
   m_timer->stop();
   QAudioBuffer buffer = m_decoder->read();
   if (!buffer.isValid()) {
     return;
   }
   if (buffer.startTime() > 120000000LL) {
     finishDecoding();
     return;
   }
   emit bufferReady(QByteArray(buffer.constData<char>(), buffer.byteCount()));
   m_timer->start();
 }
 
 /**
  * Receive an error from the decoder.
  */
 void QtFingerprintDecoder::receiveError()
 {
   m_timer->stop();
   m_decoder->stop();
   emit error(FingerprintCalculator::DecoderError);
 }
 
 /**
  * Receive a timeout.
  */
 void QtFingerprintDecoder::receiveTimeout()
 {
   m_decoder->stop();
   emit error(FingerprintCalculator::Timeout);
 }
 
 /**
  * Finish decoding.
  */
 void QtFingerprintDecoder::finishDecoding()
 {
   m_timer->stop();
   int duration = m_decoder->duration() / 1000LL;
   m_decoder->stop();
   emit finished(duration);
 }
 
 
 /**
  * Create concrete fingerprint decoder.
  * @param parent parent object
  * @return fingerprint decoder instance.
  * @remarks This static method will be implemented by the concrete
  * fingerprint decoder which is used.
  */
 AbstractFingerprintDecoder*
 AbstractFingerprintDecoder::createFingerprintDecoder(QObject* parent) {
   return new QtFingerprintDecoder(parent);
 }