added dithering support

git-svn-id: http://svn.code.sf.net/p/qmmp-dev/code/trunk/qmmp@6008 90c681e8-e032-0410-971d-27865f9a5e38

8 files changed, 111 insertions, 36 deletions

diff --git a/src/qmmp/dithering.cpp b/src/qmmp/dithering.cpp
index dd5513b47..32dcb9890 100644
--- a/src/qmmp/dithering.cpp
+++ b/src/qmmp/dithering.cpp
@@ -2,7 +2,7 @@
  *  Based on madplay project                                               *
  *                                                                         *
  * Copyright (C) 2000-2004 Robert Leslie <rob@mars.org>                    *
- * Copyright (C) 2015 Ilya Kotov forkotov02@hotmail.ru                     *
+ * Copyright (C) 2016 Ilya Kotov forkotov02@hotmail.ru                     *
  *                                                                         *
  *   This program is free software; you can redistribute it and/or modify  *
  *   it under the terms of the GNU General Public License as published by  *
@@ -24,45 +24,66 @@
 
 Dithering::Dithering() : Effect()
 {
-    qDebug("=========================");
-
-    float output, random;
-
-    for(int i = 0; i < 9; ++i)
-    {
-        m_dither[i].error[0] = 0.0f;
-        m_dither[i].error[1] = 0.0f;
-        m_dither[i].error[2] = 0.0f;
-        m_dither[i].random = 0.0f;
-    }
-
-    //for(int i = 0; i < 500; ++i)
-    //    audioLinearDither(0, &m_dither[0]);
-
-    qDebug("=%x=", 1<< 8);
+    m_lsb = 0.0f;
+    m_required = false;
+    m_enabled = false;
 }
 
 void Dithering::configure(quint32 srate, ChannelMap map)
 {
     m_chan = map.count();
+    m_required = false;
     for(int i = 0; i < 9; ++i)
     {
         m_dither[i].error[0] = 0.0f;
         m_dither[i].error[1] = 0.0f;
         m_dither[i].error[2] = 0.0f;
-        m_dither[i].random = 0.0f;
+        m_dither[i].random = 0;
     }
     Effect::configure(srate, map);
 }
 
+void Dithering::setFormats(Qmmp::AudioFormat in, Qmmp::AudioFormat out)
+{
+    m_required = false;
+    if(AudioParameters::sampleSize(in) > AudioParameters::sampleSize(out))
+    {
+        switch (out)
+        {
+        case Qmmp::PCM_S8:
+        case Qmmp::PCM_U8:
+            m_lsb = 1.0f / 0x80;
+            m_required = true;
+            break;
+        case Qmmp::PCM_S16LE:
+        case Qmmp::PCM_S16BE:
+        case Qmmp::PCM_U16LE:
+        case Qmmp::PCM_U16BE:
+            m_lsb = 1.0f / 0x8000;
+            m_required = true;
+            break;
+        default:
+            ;
+        }
+    }
+    (m_required && m_enabled) ? qDebug("Dithering: enabled") : qDebug("Dithering: disabled");
+}
+
 void Dithering::applyEffect(Buffer *b)
 {
-    for(size_t i = 0; i < b->samples; ++i)
+    if(m_required && m_enabled)
     {
-        b->data[i] = audioLinearDither(b->data[i], &m_dither[i % m_chan]);
+        for(size_t i = 0; i < b->samples; ++i)
+            b->data[i] = audioLinearDither(b->data[i], &m_dither[i % m_chan]);
     }
 }
 
+void Dithering::setEnabled(bool enabled)
+{
+    m_enabled = enabled;
+    (m_required && m_enabled) ? qDebug("Dithering: enabled") : qDebug("Dithering: disabled");
+}
+
 quint32 Dithering::prng(quint32 state) // 32-bit pseudo-random number generator
 {
     return (state * 0x0019660dL + 0x3c6ef35fL) & 0xffffffffL;
@@ -78,11 +99,12 @@ float Dithering::audioLinearDither(float sample, AudioDither *dither)
     dither->error[2] = dither->error[1];
     dither->error[1] = dither->error[0] / 2;
 
-    output = sample;
+    /* bias */
+    output = sample + m_lsb;
 
     /* dither */
     random = prng(dither->random);
-    output += ((float) (random & 0x0000ffffL) - (dither->random & 0x0000ffffL)) / 0xffffffffL;
+    output += (float)(random - dither->random) / 0xffffffffL * m_lsb;
     dither->random = random;
 
     /* clip */
@@ -93,12 +115,12 @@ float Dithering::audioLinearDither(float sample, AudioDither *dither)
         if (sample > 1.0f)
             sample = 1.0f;
     }
-    else if (output < 1.0f)
+    else if (output < -1.0f)
     {
-        output = 1.0f;
+        output = -1.0f;
 
-        if (sample < 1.0f)
-            sample = 1.0f;
+        if (sample < -1.0f)
+            sample = -1.0f;
     }
 
     /* error feedback */
diff --git a/src/qmmp/dithering_p.h b/src/qmmp/dithering_p.h
index db25c00d2..a80a84504 100644
--- a/src/qmmp/dithering_p.h
+++ b/src/qmmp/dithering_p.h
@@ -2,7 +2,7 @@
  *  Based on madplay project                                               *
  *                                                                         *
  * Copyright (C) 2000-2004 Robert Leslie <rob@mars.org>                    *
- * Copyright (C) 2015 Ilya Kotov forkotov02@hotmail.ru                     *
+ * Copyright (C) 2016 Ilya Kotov forkotov02@hotmail.ru                     *
  *                                                                         *
  *   This program is free software; you can redistribute it and/or modify  *
  *   it under the terms of the GNU General Public License as published by  *
@@ -35,7 +35,9 @@ public:
     Dithering();
 
     void configure(quint32 srate, ChannelMap map);
+    void setFormats(Qmmp::AudioFormat in, Qmmp::AudioFormat out);
     void applyEffect(Buffer *b);
+    void setEnabled(bool enabled);
 
 private:
     int m_chan;
@@ -48,6 +50,9 @@ private:
     } AudioDither;
 
     AudioDither m_dither[9];
+    float m_lsb;
+    bool m_required, m_enabled;
+
 
     quint32 prng(quint32 state);
     float audioLinearDither(float sample, AudioDither *dither);
diff --git a/src/qmmp/qmmpaudioengine.cpp b/src/qmmp/qmmpaudioengine.cpp
index b736db2e8..b1f0b03aa 100644
--- a/src/qmmp/qmmpaudioengine.cpp
+++ b/src/qmmp/qmmpaudioengine.cpp
@@ -49,14 +49,15 @@ QmmpAudioEngine::QmmpAudioEngine(QObject *parent)
     m_output = 0;
     m_muted = false;
     m_replayGain = 0;
+    m_dithering = 0;
     m_converter = new AudioConverter;
+
     m_settings = QmmpSettings::instance();
     connect(m_settings,SIGNAL(replayGainSettingsChanged()), SLOT(updateReplayGainSettings()));
+    connect(m_settings,SIGNAL(audioSettingsChanged()), SLOT(updateAudioSettings()));
     connect(m_settings, SIGNAL(eqSettingsChanged()), SLOT(updateEqSettings()));
     reset();
     m_instance = this;
-
-    Dithering d;
 }
 
 QmmpAudioEngine::~QmmpAudioEngine()
@@ -339,6 +340,16 @@ void QmmpAudioEngine::updateReplayGainSettings()
     }
 }
 
+void QmmpAudioEngine::updateAudioSettings()
+{
+    if(m_dithering)
+    {
+        mutex()->lock();
+        m_dithering->setEnabled(m_settings->useDithering());
+        mutex()->unlock();
+    }
+}
+
 void QmmpAudioEngine::updateEqSettings()
 {
     mutex()->lock();
@@ -362,6 +373,7 @@ void QmmpAudioEngine::run()
     addOffset(); //offset
     mutex()->unlock();
     m_output->start();
+    m_dithering->setFormats(m_decoder->audioParameters().format(), m_output->format());
     StateHandler::instance()->dispatch(Qmmp::Buffering);
     StateHandler::instance()->dispatch(m_decoder->totalTime());
     StateHandler::instance()->dispatch(Qmmp::Playing);
@@ -461,7 +473,6 @@ void QmmpAudioEngine::run()
                     mutex()->unlock();
                     sendMetaData();
                     addOffset(); //offset
-                    continue;
                 }
                 else
                 {
@@ -482,9 +493,13 @@ void QmmpAudioEngine::run()
                         StateHandler::instance()->dispatch(m_decoder->totalTime());
                         sendMetaData();
                         addOffset(); //offset
-                        continue;
                     }
                 }
+                if(m_output)
+                {
+                    m_dithering->setFormats(m_decoder->audioParameters().format(), m_output->format());
+                    continue;
+                }
             }
 
             flush(true);
@@ -623,6 +638,7 @@ void QmmpAudioEngine::prepareEffects(Decoder *d)
         }
     }
     m_replayGain = 0;
+    m_dithering = 0;
     QList <Effect *> tmp_effects = m_effects;
     m_effects.clear();
 
@@ -637,6 +653,12 @@ void QmmpAudioEngine::prepareEffects(Decoder *d)
                                      m_settings->replayGainPreventClipping());
         m_replayGain->setReplayGainInfo(d->replayGainInfo());
     }
+    //dithering
+    {
+        m_dithering = new Dithering;
+        m_dithering->configure(m_ap.sampleRate(), m_ap.channelMap());
+        m_effects << m_dithering;
+    }
     //channel order converter
     if(m_ap.channelMap() != m_ap.channelMap().remaped())
     {
diff --git a/src/qmmp/qmmpaudioengine_p.h b/src/qmmp/qmmpaudioengine_p.h
index 92c39fc6e..c84d36e71 100644
--- a/src/qmmp/qmmpaudioengine_p.h
+++ b/src/qmmp/qmmpaudioengine_p.h
@@ -37,6 +37,7 @@ class EffectFactory;
 class ReplayGain;
 class QmmpSettings;
 class AudioConverter;
+class Dithering;
 
 /*! @internal
  * @author Ilya Kotov <forkotov02@hotmail.ru>
@@ -62,6 +63,7 @@ public:
 private slots:
     void finish();
     void updateReplayGainSettings();
+    void updateAudioSettings();
     void updateEqSettings();
 
 private:
@@ -96,6 +98,7 @@ private:
     ReplayGain *m_replayGain;
     QmmpSettings *m_settings;
     AudioConverter *m_converter;
+    Dithering *m_dithering;
 };
 
 #endif // QMMPAUDIOENGINE_P_H
diff --git a/src/qmmp/qmmpsettings.cpp b/src/qmmp/qmmpsettings.cpp
index bd4d0faa4..497496cb9 100644
--- a/src/qmmp/qmmpsettings.cpp
+++ b/src/qmmp/qmmpsettings.cpp
@@ -38,11 +38,12 @@ QmmpSettings::QmmpSettings(QObject *parent) : QObject(parent)
     m_rg_mode = (ReplayGainMode) settings.value("mode", REPLAYGAIN_DISABLED).toInt();
     m_rg_preamp = settings.value("preamp", 0.0).toDouble();
     m_rg_defaut_gain = settings.value("default_gain", 0.0).toDouble();
-    m_rg_prevent_clipping = settings.value("prevent_clipping", false).toBool();
+    m_rg_prevent_clipping = settings.value("prevent_clipping", true).toBool();
     settings.endGroup();
     //audio settings
     m_aud_software_volume = settings.value("Output/software_volume", false).toBool();
     m_aud_16bit = settings.value("Output/use_16bit", false).toBool();
+    m_aud_dithering = settings.value("Output/dithering", true).toBool();
     //cover settings
     settings.beginGroup("Cover");
     m_cover_inc = settings.value("include", (QStringList() << "*.jpg" << "*.png")).toStringList();
@@ -111,10 +112,16 @@ bool QmmpSettings::use16BitOutput() const
     return m_aud_16bit;
 }
 
-void QmmpSettings::setAudioSettings(bool soft_volume, bool use_16bit)
+bool QmmpSettings::useDithering() const
+{
+    return m_aud_dithering;
+}
+
+void QmmpSettings::setAudioSettings(bool soft_volume, bool use_16bit, bool use_dithering)
 {
     m_aud_software_volume = soft_volume;
     m_aud_16bit = use_16bit;
+    m_aud_dithering = use_dithering;
     m_timer->start();
     emit audioSettingsChanged();
 }
@@ -218,6 +225,7 @@ void QmmpSettings::sync()
     //audio settings
     settings.setValue("Output/software_volume", m_aud_software_volume);
     settings.setValue("Output/use_16bit", m_aud_16bit);
+    settings.setValue("Output/dithering", m_aud_dithering);
     //cover settings
     settings.beginGroup("Cover");
     settings.setValue("include", m_cover_inc);
diff --git a/src/qmmp/qmmpsettings.h b/src/qmmp/qmmpsettings.h
index 8b4392288..af8b465fa 100644
--- a/src/qmmp/qmmpsettings.h
+++ b/src/qmmp/qmmpsettings.h
@@ -87,11 +87,16 @@ public:
      */
     bool use16BitOutput() const;
     /*!
+     * Returns \b true if dithering is enabled; otherwise returns \b false.
+     */
+    bool useDithering() const;
+    /*!
      * Sets audio settings.
      * @param soft_volume State of software volume.
      * @param use_16bit State of the 16-bit audio converter.
+     * @param use_dithering Enable/Disable audio dithering.
      */
-    void setAudioSettings(bool soft_volume, bool use_16bit);
+    void setAudioSettings(bool soft_volume, bool use_16bit, bool use_dithering);
     /*!
      * If \b include is \b true, this function returns include cover file name filters,
      * otherwise returns exclude filters.
@@ -208,6 +213,7 @@ private:
     //audio settings
     bool m_aud_software_volume;
     bool m_aud_16bit;
+    bool m_aud_dithering;
     //cover settings
     QStringList m_cover_inc;
     QStringList m_cover_exclude;
diff --git a/src/qmmpui/configdialog.cpp b/src/qmmpui/configdialog.cpp
index d0d1da687..f84123621 100644
--- a/src/qmmpui/configdialog.cpp
+++ b/src/qmmpui/configdialog.cpp
@@ -1,5 +1,5 @@
 /***************************************************************************
- *   Copyright (C) 2007-2014 by Ilya Kotov                                 *
+ *   Copyright (C) 2007-2016 by Ilya Kotov                                 *
  *   forkotov02@hotmail.ru                                                 *
  *                                                                         *
  *   This program is free software; you can redistribute it and/or modify  *
@@ -151,6 +151,7 @@ void ConfigDialog::readSettings()
     //audio
     m_ui->softVolumeCheckBox->setChecked(gs->useSoftVolume());
     m_ui->use16BitCheckBox->setChecked(gs->use16BitOutput());
+    m_ui->ditheringCheckBox->setChecked(gs->useDithering());
     m_ui->bufferSizeSpinBox->setValue(gs->bufferSize());
     //geometry
     QSettings settings (Qmmp::configFile(), QSettings::IniFormat);
@@ -408,7 +409,8 @@ void ConfigDialog::saveSettings()
                               m_ui->preampDoubleSpinBox->value(),
                               m_ui->defaultGainDoubleSpinBox->value(),
                               m_ui->clippingCheckBox->isChecked());
-    gs->setAudioSettings(m_ui->softVolumeCheckBox->isChecked(), m_ui->use16BitCheckBox->isChecked());
+    gs->setAudioSettings(m_ui->softVolumeCheckBox->isChecked(), m_ui->use16BitCheckBox->isChecked(),
+                         m_ui->ditheringCheckBox->isChecked());
     gs->setBufferSize(m_ui->bufferSizeSpinBox->value());
     gs->setDetermineFileTypeByContent(m_ui->byContentCheckBox->isChecked());
     QList<QVariant> var_sizes;
diff --git a/src/qmmpui/forms/configdialog.ui b/src/qmmpui/forms/configdialog.ui
index 844af865e..1cf7a46ff 100644
--- a/src/qmmpui/forms/configdialog.ui
+++ b/src/qmmpui/forms/configdialog.ui
@@ -820,6 +820,13 @@
              </property>
             </widget>
            </item>
+           <item row="3" column="0" colspan="3">
+            <widget class="QCheckBox" name="ditheringCheckBox">
+             <property name="text">
+              <string>Use dithering</string>
+             </property>
+            </widget>
+           </item>
           </layout>
          </widget>
         </item>