view audioio/AudioCallbackPlayTarget.h @ 12:29b38a641d43

* Implement play mute, level and pan controls and a layer visibility control
* Handle swapping the buffers in AudioCallbackPlaySource more gracefully, so
  that in many cases it can be done inaudibly.  Still gets it wrong when
  playing in a noncontiguous selection.
* Fix to SV file save for non-2d sparse models
* Fixes to LED button drawing and AudioDial mouse functionality
* Add progress bar for Ogg file import
* Reshuffle PropertyContainer and its subclasses so it can be a QObject
* Add layer dormancy (invisible layer permitted to free its cache space)
* Optimisations to SpectrogramLayer, removing locks when reading/writing
  individual pixels in the cache (should be unnecessary there) -- there's
  still an issue here as we need a lock when reading from the model in
  case the model is replaced, and we don't currently have one
* Several munlock() calls to make it harder to exhaust real memory if
  running in an RT mode with mlockall() active

/* -*- c-basic-offset: 4 -*-  vi:set ts=8 sts=4 sw=4: */

/*
    A waveform viewer and audio annotation editor.
    Chris Cannam, Queen Mary University of London, 2005-2006
    
    This is experimental software.  Not for distribution.
*/

#ifndef _AUDIO_CALLBACK_PLAY_TARGET_H_
#define _AUDIO_CALLBACK_PLAY_TARGET_H_

#include <QObject>

class AudioCallbackPlaySource;

class AudioCallbackPlayTarget : public QObject
{
    Q_OBJECT

public:
    AudioCallbackPlayTarget(AudioCallbackPlaySource *source);
    virtual ~AudioCallbackPlayTarget();

    virtual bool isOK() const = 0;

    float getOutputGain() const {
	return m_outputGain;
    }

public slots:
    /**
     * Set the playback gain (0.0 = silence, 1.0 = levels unmodified)
     */
    virtual void setOutputGain(float gain);

    /**
     * The main source model (providing the playback sample rate) has
     * been changed.  The target should query the source's sample
     * rate, set its output sample rate accordingly, and call back on
     * the source's setTargetSampleRate to indicate what sample rate
     * it succeeded in setting at the output.  If this differs from
     * the model rate, the source will resample.
     */
    virtual void sourceModelReplaced() = 0;

protected:
    AudioCallbackPlaySource *m_source;
    float m_outputGain;
};

#endif