kttsd/libkttsd/stretcher.cpp

   1 /***************************************************** vim:set ts=4 sw=4 sts=4:
   2   Description:
   3      Speeds up or slows down an audio file by stretching the audio stream.
   4      Uses the sox program to do the stretching.
   5
   6   Copyright:
   7   (C) 2004 by Gary Cramblitt <garycramblitt@comcast.net>
   8   -------------------
   9   Original author: Gary Cramblitt <garycramblitt@comcast.net>
  10
  11   This program is free software; you can redistribute it and/or modify
  12   it under the terms of the GNU General Public License as published by
  13   the Free Software Foundation; either version 2 of the License, or
  14   (at your option) any later version.
  15
  16   This program is distributed in the hope that it will be useful,
  17   but WITHOUT ANY WARRANTY; without even the implied warranty of
  18   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19   GNU General Public License for more details.
  20
  21   You should have received a copy of the GNU General Public License
  22   along with this program; if not, write to the Free Software
  23   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
  24  ******************************************************************************/
  25
  26 // Stretcher includes.
  27 #include "stretcher.h"
  28 #include "stretcher.moc"
  29
  30 // KDE includes.
  31 #include <k3process.h>
  32 #include <kdebug.h>
  33
  34 /**
  35  * Constructor.
  36  */
  37 Stretcher::Stretcher(QObject *parent, const char *name) :
  38     QObject(parent)
  39 {
  40     Q_UNUSED(name);
  41     m_state = 0;
  42     m_stretchProc = 0;
  43 }
  44
  45 /**
  46  * Destructor.
  47  */
  48 Stretcher::~Stretcher()
  49 {
  50     delete m_stretchProc;
  51 }
  52
  53 /**
  54  * Stretch the given input file to an output file.
  55  * @param inFilename        Name of input audio file.
  56  * @param outFilename       Name of output audio file.
  57  * @param stretchFactor     Amount to stretch.  2.0 is twice as slow.  0.5 is twice as fast.
  58  * @return                  False if an error occurs.
  59  */
  60 bool Stretcher::stretch(const QString &inFilename, const QString &outFilename, float stretchFactor)
  61 {
  62     if (m_stretchProc) return false;
  63     m_outFilename = outFilename;
  64     m_stretchProc = new K3Process;
  65     QString stretchStr = QString("%1").arg(stretchFactor, 0, 'f', 3);
  66     *m_stretchProc << "sox" << inFilename << outFilename << "stretch" << stretchStr;
  67     connect(m_stretchProc, SIGNAL(processExited(K3Process*)),
  68         this, SLOT(slotProcessExited(K3Process*)));
  69     if (!m_stretchProc->start(K3Process::NotifyOnExit, K3Process::NoCommunication))
  70     {
  71         kDebug() << "Stretcher::stretch: Error starting audio stretcher process.  Is sox installed?";
  72         return false;
  73     }
  74     m_state = ssStretching;
  75     return true;
  76 }
  77
  78 void Stretcher::slotProcessExited(K3Process*)
  79 {
  80     m_stretchProc->deleteLater();
  81     m_stretchProc = 0;
  82     m_state = ssFinished;
  83     emit stretchFinished();
  84 }
  85
  86 /**
  87  * Returns the state of the Stretcher.
  88  */
  89 int Stretcher::getState() { return m_state; }
  90
  91 /**
  92  * Returns the output filename (as given in call to stretch).
  93  */
  94 QString Stretcher::getOutFilename() { return m_outFilename; }
  95
  96 /**
  97  * Acknowledges the finished stretching.
  98  */
  99 void Stretcher::ackFinished() { m_state = ssIdle; }
 100