scenic

// audioSource.h

// Copyright 2008 Koya Charles & Tristan Matthews

//

// This file is part of [propulse]ART.

//

// [propulse]ART 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 3 of the License, or

// (at your option) any later version.

//

// [propulse]ART 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 [propulse]ART.  If not, see <http://www.gnu.org/licenses/>.

//

/** \file audioSource.h

 *      A family of classes representing different types/sources of audio input.

 */

#ifndef _AUDIO_SOURCE_H_

#define _AUDIO_SOURCE_H_

#include "gstLinkable.h"

#include "interleave.h"

#include "busMsgHandler.h"

// forward declarations

class AudioSourceConfig;

/** 

 *  Abstract base class from which our audio sources are derived.

 *  Uses template method to define the initialization process that subclasses will have to

 *  implement (in part) and/or override. Any direct, concrete descendant of this class will not

 *  need to have its audio frames interleaved.

 */

class AudioSource : public GstLinkableSource

{

    public:

        ~AudioSource();

        virtual void init();

    protected:

        explicit AudioSource(const AudioSourceConfig &config);

        /// Implemented by subclasses to perform other specific initialization 

        virtual void sub_init() = 0;

        /// Audio parameter object 

        const AudioSourceConfig &config_;

        /// GstElements representing each source and audioconvert 

        GstElement *source_;

    private:

        GstElement *srcElement() { return source_; }

        /// No Copy Constructor

        AudioSource(const AudioSource&);     

        /// No Assignment Operator

        AudioSource& operator=(const AudioSource&);     

};

/** 

 * Abstract child of AudioSource whose audio frames must be interleaved before pushing audio further down pipeline.

 */

class InterleavedAudioSource

    : public AudioSource

{

    protected:

        /// Object initializer 

        void sub_init();

        explicit InterleavedAudioSource(const AudioSourceConfig &config);

        ~InterleavedAudioSource();

        /// Object which performs the interleaving of this source's channels 

        Interleave interleave_;

        std::vector<GstElement*> sources_, aconvs_;

    private:

        GstElement *srcElement() { return interleave_.srcElement(); }

};

/** 

 *  Concrete InterleavedAudioSource which gives us an array of sine-wave generating sources.

 *

 *  AudioTestSource generates sine-tones, each of which alternate between two hard-coded frequencies. Their

 *  combined output is then interleaved.

 */

class AudioTestSource : public InterleavedAudioSource

{

    public:

        explicit AudioTestSource(const AudioSourceConfig &config);

    private:

        void sub_init();

        ~AudioTestSource();

        static gboolean timedCallback(GstClock *clock, 

                                      GstClockTime time, 

                                      GstClockID id,

                                      gpointer user_data);

        void toggle_frequency();

        GstClockID clockId_;

        int offset_;

        static const double FREQUENCY[2][8];

        /// No Copy Constructor

        AudioTestSource(const AudioTestSource&);     

        /// No Assignment Operator

        AudioTestSource& operator=(const AudioTestSource&);     

};

/** 

 *  \class AudioFileSource

 *  Concrete AudioSource which provides playback of files. 

 *

 *  AudioFileSource plays back a file (determined by its AudioSourceConfig object). Depending

 *  on its AudioSourceConfig object, it may loop the file. It implements the BusMsgHandler interface

 *  so that it knows when an End-of-Signal event occurs, in which case it may

 *  play the file again if it has been set to continue to play the file (either infinitely or for a finite

 *  number of plays).

 */

class AudioFileSource : public AudioSource, public BusMsgHandler

{

    public:

        explicit AudioFileSource(const AudioSourceConfig &config);

    private:

        ~AudioFileSource();

        bool handleBusMsg(_GstMessage *msg);

        static void cb_new_src_pad(GstElement * srcElement, 

                                   GstPad * srcPad, 

                                   gboolean last,

                                   void *data);

        void loop(int nTimes);

        void sub_init();

        void restartPlayback();

        GstElement* decoder_;

        GstElement* aconv_;

        int loopCount_;

        static const int LOOP_INFINITE;

        /// No Copy Constructor

        AudioFileSource(const AudioFileSource&);     

        /// No Assignment Operator

        AudioFileSource& operator=(const AudioFileSource&);     

};

/** 

 *  Concrete AudioSource which captures audio from ALSA

 *  Has caps filter to allow number of channels to be variable.

 */

class AudioAlsaSource : public AudioSource

{

    public:

        explicit AudioAlsaSource(const AudioSourceConfig &config);

    private:

        ~AudioAlsaSource();

        void sub_init();

        GstElement *srcElement() { return capsFilter_; }

        GstElement *capsFilter_;

        GstElement *aconv_;

        /// No Copy Constructor

        AudioAlsaSource(const AudioAlsaSource&);     

        /// No Assignment Operator

        AudioAlsaSource& operator=(const AudioAlsaSource&);     

};

/** 

 *  Concrete AudioSource which captures audio from PulseAudio

 *  Has caps filter to allow number of channels to be variable.

 */

class AudioPulseSource : public AudioSource

{

    public:

        explicit AudioPulseSource(const AudioSourceConfig &config);

    private:

        ~AudioPulseSource();

        void sub_init();

        GstElement *srcElement() { return capsFilter_; }

        GstElement *capsFilter_;

        GstElement *aconv_;

        /// No Copy Constructor

        AudioPulseSource(const AudioPulseSource&);     

        /// No Assignment Operator

        AudioPulseSource& operator=(const AudioPulseSource&);     

};

/** 

 *  Concrete AudioSource which captures audio from JACK, 

 *  and interleaves incoming jack buffers into one multichannel stream.

 */

class AudioJackSource : public AudioSource

{

    public:

        explicit AudioJackSource(const AudioSourceConfig &config);

    private:

        ~AudioJackSource();

        GstElement *srcElement() { return capsFilter_; }

        void sub_init();

        GstElement *capsFilter_;

        GstElement *aconv_;

        /// No Copy Constructor

        AudioJackSource(const AudioJackSource&);     

        /// No Assignment Operator

        AudioJackSource& operator=(const AudioJackSource&);     

};

/** 

 *  Concrete AudioSource which captures audio from dv device.

 *

 *  This object is tightly coupled with VideoDvSource, as both (if present) will share one source_ GstElement, 

 *  and one dvdemux GstElement. It will look for both of these in the pipeline before trying to instantiate them. 

 *  If these GstElement are already present, AudioDvSource will simply store their addresses and link to them, if not

 *  it will create them. Audio can only be stereo or 4 channels according to gstreamer.

 */

class AudioDvSource : public AudioSource

{

    public:

        explicit AudioDvSource(const AudioSourceConfig &config);

    private:

        ~AudioDvSource();

        void sub_init();

        GstElement *queue_;

        GstElement *srcElement() { return queue_; }

        /// No Copy Constructor

        AudioDvSource(const AudioDvSource&);     

        /// No Assignment Operator

        AudioDvSource& operator=(const AudioDvSource&);     

};

#endif //_AUDIO_SOURCE_H_