Work on extending the framework for accomodating effects.

This extends the framework for being able to handle audio effects, largely
affecting how the audio chain is set up, connected and disconnected, and
therefore the Backend has been refactored slightly, and the class MediaNode
introduced, see its documentation.

In addition two effects has been written: BassBoost and AudioEqualizer.

1 files changed, 105 insertions, 0 deletions

diff --git a/src/3rdparty/phonon/mmf/abstractaudioeffect.cpp b/src/3rdparty/phonon/mmf/abstractaudioeffect.cpp
new file mode 100644
index 0000000..4c876e1
--- /dev/null
+++ b/src/3rdparty/phonon/mmf/abstractaudioeffect.cpp
@@ -0,0 +1,105 @@
+/*  This file is part of the KDE project.
+
+Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
+
+This library is free software: you can redistribute it and/or modify
+it under the terms of the GNU Lesser General Public License as published by
+the Free Software Foundation, either version 2.1 or 3 of the License.
+
+This library 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 Lesser General Public License for more details.
+
+You should have received a copy of the GNU Lesser General Public License
+along with this library.  If not, see <http://www.gnu.org/licenses/>.
+
+*/
+
+#include <AudioEffectBase.h>
+#include "mediaobject.h"
+
+#include "abstractaudioeffect.h"
+
+QT_BEGIN_NAMESPACE
+
+using namespace Phonon;
+using namespace Phonon::MMF;
+
+AbstractAudioEffect::AbstractAudioEffect(QObject *parent,
+                                         const QList<EffectParameter> &params) : MediaNode::MediaNode(parent)
+                                                                               , m_params(params)
+                                                                               , m_isApplied(false)
+{
+}
+
+bool AbstractAudioEffect::disconnectMediaNode(MediaNode *target)
+{
+    MediaNode::disconnectMediaNode(target);
+    m_effect.reset();
+    return true;
+}
+
+QList<EffectParameter> AbstractAudioEffect::parameters() const
+{
+    return m_params;
+}
+
+QVariant AbstractAudioEffect::parameterValue(const EffectParameter &queriedParam) const
+{
+    const QVariant &val = m_values.value(queriedParam.id());
+
+    if (val.isNull())
+        return queriedParam.defaultValue();
+    else
+        return val;
+}
+
+void AbstractAudioEffect::setParameterValue(const EffectParameter &param,
+                                            const QVariant &newValue)
+{
+    m_values.insert(param.id(), newValue);
+    parameterChanged(param.id(), newValue);
+}
+
+bool AbstractAudioEffect::activateBackwardsInChain(MediaNode *target)
+{
+    // TODO we need to walk forward too.
+    MediaNode *current = target;
+
+    while (current) {
+        MMF::MediaObject *const mo = qobject_cast<MMF::MediaObject *>(current);
+        if(!mo)
+            continue;
+
+        AudioPlayer *const ap = qobject_cast<AudioPlayer *>(mo->abstractPlayer());
+
+        if (ap) {
+            activateOn(ap->player());
+            // There might be stuff before the mediaobject, but
+            // that's undefined for us.
+            return true;
+        }
+        else
+            current = current->source();
+    }
+
+    return false;
+}
+
+bool AbstractAudioEffect::connectMediaNode(MediaNode *target)
+{
+    /**
+     * We first call this function, so source() and target()
+     * is properly set up.
+     */
+    MediaNode::connectMediaNode(target);
+
+    if (!m_isApplied && activateBackwardsInChain(target))
+        m_isApplied = true;
+
+    return true;
+}
+
+QT_END_NAMESPACE
+