drivers/audio/AudioOutputDevice.h

/***************************************************************************
 *                                                                         *
 *   LinuxSampler - modular, streaming capable sampler                     *
 *                                                                         *
 *   Copyright (C) 2003, 2004 by Benno Senoner and Christian Schoenebeck   *
 *   Copyright (C) 2005, 2006 Christian Schoenebeck                        *
 *                                                                         *
 *   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  *
 *   the Free Software Foundation; either version 2 of the License, or     *
 *   (at your option) any later version.                                   *
 *                                                                         *
 *   This program 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 this program; if not, write to the Free Software           *
 *   Foundation, Inc., 59 Temple Place, Suite 330, Boston,                 *
 *   MA  02111-1307  USA                                                   *
 ***************************************************************************/

#ifndef __LS_AUDIOOUTPUTDEVICE_H__
#define __LS_AUDIOOUTPUTDEVICE_H__

#include <set>
#include <map>
#include <vector>
#include <stdexcept>

#include "../../common/global.h"
#include "../../common/Exception.h"
#include "../Device.h"
#include "../DeviceParameter.h"
#include "../../engines/common/Engine.h"
#include "AudioChannel.h"
#include "../../common/SynchronizedConfig.h"

namespace LinuxSampler {

    // just symbol prototyping
    class Engine;

    /** Abstract base class for audio output drivers in LinuxSampler
     *
     * This class will be derived by specialized classes which implement the
     * connection to a specific audio output system (e.g. Alsa, Jack,
     * CoreAudio).
     */
    class AudioOutputDevice : public Device {
        public:

            /////////////////////////////////////////////////////////////////
            // Device parameters

            /** Device Parameter 'ACTIVE'
             *
             * Used to activate / deactivate the audio output device.
             */
            class ParameterActive : public DeviceCreationParameterBool {
                public:
                    ParameterActive();
                    ParameterActive(String s);
                    virtual String Description();
                    virtual bool   Fix();
                    virtual bool   Mandatory();
                    virtual std::map<String,DeviceCreationParameter*> DependsAsParameters();
                    virtual optional<bool> DefaultAsBool(std::map<String,String> Parameters);
                    virtual void OnSetValue(bool b) throw (Exception);
                    static String Name();
            };

            /** Device Parameter 'SAMPLERATE'
             *
             * Used to set the sample rate of the audio output device.
             */
            class ParameterSampleRate : public DeviceCreationParameterInt {
                public:
                    ParameterSampleRate();
                    ParameterSampleRate(String s);
                    virtual String Description();
                    virtual bool   Fix();
                    virtual bool   Mandatory();
                    virtual std::map<String,DeviceCreationParameter*> DependsAsParameters();
                    virtual optional<int>    DefaultAsInt(std::map<String,String> Parameters);
                    virtual optional<int>    RangeMinAsInt(std::map<String,String> Parameters);
                    virtual optional<int>    RangeMaxAsInt(std::map<String,String> Parameters);
                    virtual std::vector<int> PossibilitiesAsInt(std::map<String,String> Parameters);
                    virtual void             OnSetValue(int i) throw (Exception);
                    static String Name();
            };

            /** Device Parameters 'CHANNELS'
             *
             * Used to increase / decrease the number of audio channels of
             * audio output device.
             */
            class ParameterChannels : public DeviceCreationParameterInt {
                public:
                    ParameterChannels();
                    ParameterChannels(String s);
                    virtual String Description();
                    virtual bool   Fix();
                    virtual bool   Mandatory();
                    virtual std::map<String,DeviceCreationParameter*> DependsAsParameters();
                    virtual optional<int>    DefaultAsInt(std::map<String,String> Parameters);
                    virtual optional<int>    RangeMinAsInt(std::map<String,String> Parameters);
                    virtual optional<int>    RangeMaxAsInt(std::map<String,String> Parameters);
                    virtual std::vector<int> PossibilitiesAsInt(std::map<String,String> Parameters);
                    virtual void             OnSetValue(int i) throw (Exception);
                    static String Name();
            };


            /////////////////////////////////////////////////////////////////
            // abstract methods
            //     (these have to be implemented by the descendant)

            /**
             * Start playback of audio signal on the audio device. It's the
             * responsibility of the implementing audio device to call the
             * RenderAudio(uint Samples) method of all connected engines.
             * This will cause the engines to continue to render 'Samples'
             * number of audio sample points and the engines will
             * automatically add their audio signals to the audio buffers of
             * the audio channels of this audio device. So the implementing
             * audio device just has to access the buffers of it's audio
             * channels.
             *
             * @throws AudioOutputException  if playback can not be started
             * @see AudioChannel
             */
            virtual void Play() = 0;

            /**
             * Returns true if the audio device is currently playing back.
             */
            virtual bool IsPlaying() = 0;

            /**
             * Stop playback of audio signal on the audio device. The
             * implementing audio device will stop calling the RenderAudio()
             * method of all connected engines and close it's connection to
             * audio output system.
             */
            virtual void Stop() = 0;

            /**
             * Maximum amount of sample points the implementing audio
             * device will ever demand the sampler engines to write in one
             * fragment cycle / period. Simple audio device drivers usually
             * have a fixed fragment size, so those devices just would return
             * the fragment size in this method.
             *
             * @returns  max. amount of sample points ever
             */
            virtual uint MaxSamplesPerCycle() = 0;

            /**
             * Playback samplerate the audio device uses. The sampler engines
             * currently assume this to be a constant value for the whole
             * life time of an instance of the implementing audio device.
             *
             * @returns  sample rate in Hz
             */
            virtual uint SampleRate() = 0;

            /**
             * Return the audio output device driver name.
             */
            virtual String Driver() = 0;

            /**
             * Create new audio channel. This will be called by
             * AcquireChannels(). Each driver must implement it.
             */
            virtual AudioChannel* CreateChannel(uint ChannelNr) = 0;


            /////////////////////////////////////////////////////////////////
            // normal methods
            //     (usually not to be overriden by descendant)

            /**
             * Connect given sampler engine to this audio output device. The
             * engine will be added to the Engines container of this audio
             * device and the engine will also automatically be informed
             * about the connection.
             *
             * @param pEngine - sampler engine
             */
            void Connect(Engine* pEngine);

            /**
             * Disconnect given sampler engine from this audio output device.
             * Removes given sampler engine reference from the Engines
             * container of this audio device.
             *
             * @param pEngine - sampler engine
             */
            void Disconnect(Engine* pEngine);

            /**
             * Returns audio channel with index \a ChannelIndex or NULL if
             * index out of bounds.
             */
            AudioChannel* Channel(uint ChannelIndex);

            /**
             * This method will usually be called by the sampler engines that
             * are connected to this audio device to inform the audio device
             * how much audio channels the engine(s) need. It's the
             * responsibility of the audio device to offer that amount of
             * audio channels - again: this is not an option this is a must!
             * The engines will assume to be able to access those audio
             * channels right after. If the audio driver is not able to offer
             * that much channels, it can simply create mix channels which
             * are then just mixed to the 'real' audio channels. See
             * AudioChannel.h for details about channels and mix channels.
             *
             * @param Channels - amount of output channels required by
             *                   a sampler engine
             * @throws AudioOutputException  if desired amount of channels
             *                               cannot be offered
             * @see AudioChannel
             */
            void AcquireChannels(uint Channels);

            /**
             * Returns all device parameter settings.
             */
            std::map<String,DeviceCreationParameter*> DeviceParameters();

        protected:
            SynchronizedConfig<std::set<Engine*> >    Engines;     ///< All sampler engines that are connected to the audio output device.
            SynchronizedConfig<std::set<Engine*> >::Reader EnginesReader; ///< Audio thread access to Engines.
            std::vector<AudioChannel*>                Channels;    ///< All audio channels of the audio output device. This is just a container; the descendant has to create channels by himself.
            std::map<String,DeviceCreationParameter*> Parameters;  ///< All device parameters.

            AudioOutputDevice(std::map<String,DeviceCreationParameter*> DriverParameters);

            virtual ~AudioOutputDevice();

            /**
             * This method should be called by the AudioOutputDevice
             * descendant to let all connected engines proceed to render the
             * given amount of sample points. The engines will place their
             * calculated audio data by themselfes into the buffers of the
             * respective AudioChannel objects, so the implementing audio
             * output device just has to copy the AudioChannel buffers to
             * the output buffer(s) of its audio system.
             *
             * @returns  0 on success or the last error return code of one
             *           engine
             */
            int RenderAudio(uint Samples);

            /**
             * This can be called as an alternative to RenderAudio() for
             * just writing silence to the audio output buffers and not
             * calling the connected sampler engines for rendering audio, so
             * to provide a method to stop playback if the used audio output
             * system doesn't provide a better way.
             *
             * @returns  0 on success
             */
            int RenderSilence(uint Samples);

            friend class Sampler; // allow Sampler class to destroy audio devices

    };

    /**
     * Audio output exception that should be thrown by the AudioOutputDevice
     * descendants in case initialization of the audio output system failed
     * (which should be done in the constructor of the AudioOutputDevice
     * descendant).
     */
    class AudioOutputException : public Exception {
        public:
            AudioOutputException(const std::string& msg) : Exception(msg) {}
    };
}

#endif // __LS_AUDIOOUTPUTDEVICE_H__
1	schoenebeck	200	/***************************************************************************
2			* *
3			* LinuxSampler - modular, streaming capable sampler *
4			* *
5			* Copyright (C) 2003, 2004 by Benno Senoner and Christian Schoenebeck *
6	schoenebeck	880	* Copyright (C) 2005, 2006 Christian Schoenebeck *
7	schoenebeck	200	* *
8			* This program is free software; you can redistribute it and/or modify *
9			* it under the terms of the GNU General Public License as published by *
10			* the Free Software Foundation; either version 2 of the License, or *
11			* (at your option) any later version. *
12			* *
13			* This program is distributed in the hope that it will be useful, *
14			* but WITHOUT ANY WARRANTY; without even the implied warranty of *
15			* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the *
16			* GNU General Public License for more details. *
17			* *
18			* You should have received a copy of the GNU General Public License *
19			* along with this program; if not, write to the Free Software *
20			* Foundation, Inc., 59 Temple Place, Suite 330, Boston, *
21			* MA 02111-1307 USA *
22			***************************************************************************/
23
24			#ifndef __LS_AUDIOOUTPUTDEVICE_H__
25			#define __LS_AUDIOOUTPUTDEVICE_H__
26
27			#include <set>
28			#include <map>
29			#include <vector>
30			#include <stdexcept>
31
32			#include "../../common/global.h"
33	schoenebeck	880	#include "../../common/Exception.h"
34	schoenebeck	207	#include "../Device.h"
35	schoenebeck	200	#include "../DeviceParameter.h"
36	schoenebeck	412	#include "../../engines/common/Engine.h"
37	schoenebeck	200	#include "AudioChannel.h"
38	persson	840	#include "../../common/SynchronizedConfig.h"
39	schoenebeck	200
40			namespace LinuxSampler {
41
42			// just symbol prototyping
43	schoenebeck	412	class Engine;
44	schoenebeck	200
45			/** Abstract base class for audio output drivers in LinuxSampler
46			*
47			* This class will be derived by specialized classes which implement the
48			* connection to a specific audio output system (e.g. Alsa, Jack,
49			* CoreAudio).
50			*/
51	schoenebeck	207	class AudioOutputDevice : public Device {
52	schoenebeck	200	public:
53
54			/////////////////////////////////////////////////////////////////
55			// Device parameters
56
57	schoenebeck	221	/** Device Parameter 'ACTIVE'
58			*
59			* Used to activate / deactivate the audio output device.
60			*/
61	schoenebeck	200	class ParameterActive : public DeviceCreationParameterBool {
62			public:
63	schoenebeck	226	ParameterActive();
64			ParameterActive(String s);
65			virtual String Description();
66			virtual bool Fix();
67			virtual bool Mandatory();
68			virtual std::map<String,DeviceCreationParameter*> DependsAsParameters();
69			virtual optional<bool> DefaultAsBool(std::map<String,String> Parameters);
70	schoenebeck	880	virtual void OnSetValue(bool b) throw (Exception);
71	schoenebeck	226	static String Name();
72	schoenebeck	200	};
73
74	schoenebeck	221	/** Device Parameter 'SAMPLERATE'
75			*
76			* Used to set the sample rate of the audio output device.
77			*/
78	schoenebeck	200	class ParameterSampleRate : public DeviceCreationParameterInt {
79			public:
80	schoenebeck	226	ParameterSampleRate();
81			ParameterSampleRate(String s);
82			virtual String Description();
83			virtual bool Fix();
84			virtual bool Mandatory();
85			virtual std::map<String,DeviceCreationParameter*> DependsAsParameters();
86			virtual optional<int> DefaultAsInt(std::map<String,String> Parameters);
87			virtual optional<int> RangeMinAsInt(std::map<String,String> Parameters);
88			virtual optional<int> RangeMaxAsInt(std::map<String,String> Parameters);
89			virtual std::vector<int> PossibilitiesAsInt(std::map<String,String> Parameters);
90	schoenebeck	880	virtual void OnSetValue(int i) throw (Exception);
91	schoenebeck	226	static String Name();
92	schoenebeck	200	};
93
94	schoenebeck	221	/** Device Parameters 'CHANNELS'
95			*
96			* Used to increase / decrease the number of audio channels of
97			* audio output device.
98			*/
99	schoenebeck	200	class ParameterChannels : public DeviceCreationParameterInt {
100			public:
101	schoenebeck	226	ParameterChannels();
102			ParameterChannels(String s);
103			virtual String Description();
104			virtual bool Fix();
105			virtual bool Mandatory();
106			virtual std::map<String,DeviceCreationParameter*> DependsAsParameters();
107			virtual optional<int> DefaultAsInt(std::map<String,String> Parameters);
108			virtual optional<int> RangeMinAsInt(std::map<String,String> Parameters);
109			virtual optional<int> RangeMaxAsInt(std::map<String,String> Parameters);
110			virtual std::vector<int> PossibilitiesAsInt(std::map<String,String> Parameters);
111	schoenebeck	880	virtual void OnSetValue(int i) throw (Exception);
112	schoenebeck	226	static String Name();
113	schoenebeck	200	};
114
115
116	schoenebeck	221
117	schoenebeck	200	/////////////////////////////////////////////////////////////////
118			// abstract methods
119			// (these have to be implemented by the descendant)
120
121			/**
122			* Start playback of audio signal on the audio device. It's the
123			* responsibility of the implementing audio device to call the
124			* RenderAudio(uint Samples) method of all connected engines.
125			* This will cause the engines to continue to render 'Samples'
126			* number of audio sample points and the engines will
127			* automatically add their audio signals to the audio buffers of
128			* the audio channels of this audio device. So the implementing
129			* audio device just has to access the buffers of it's audio
130			* channels.
131			*
132			* @throws AudioOutputException if playback can not be started
133			* @see AudioChannel
134			*/
135			virtual void Play() = 0;
136
137			/**
138			* Returns true if the audio device is currently playing back.
139			*/
140			virtual bool IsPlaying() = 0;
141
142			/**
143			* Stop playback of audio signal on the audio device. The
144			* implementing audio device will stop calling the RenderAudio()
145			* method of all connected engines and close it's connection to
146			* audio output system.
147			*/
148			virtual void Stop() = 0;
149
150			/**
151			* Maximum amount of sample points the implementing audio
152			* device will ever demand the sampler engines to write in one
153			* fragment cycle / period. Simple audio device drivers usually
154			* have a fixed fragment size, so those devices just would return
155			* the fragment size in this method.
156			*
157			* @returns max. amount of sample points ever
158			*/
159			virtual uint MaxSamplesPerCycle() = 0;
160
161			/**
162			* Playback samplerate the audio device uses. The sampler engines
163			* currently assume this to be a constant value for the whole
164			* life time of an instance of the implementing audio device.
165			*
166			* @returns sample rate in Hz
167			*/
168			virtual uint SampleRate() = 0;
169
170			/**
171	schoenebeck	226	* Return the audio output device driver name.
172	schoenebeck	200	*/
173			virtual String Driver() = 0;
174
175	schoenebeck	226	/**
176			* Create new audio channel. This will be called by
177			* AcquireChannels(). Each driver must implement it.
178			*/
179			virtual AudioChannel* CreateChannel(uint ChannelNr) = 0;
180
181
182
183	schoenebeck	200	/////////////////////////////////////////////////////////////////
184			// normal methods
185			// (usually not to be overriden by descendant)
186
187			/**
188			* Connect given sampler engine to this audio output device. The
189			* engine will be added to the Engines container of this audio
190			* device and the engine will also automatically be informed
191			* about the connection.
192			*
193	schoenebeck	412	* @param pEngine - sampler engine
194	schoenebeck	200	*/
195	schoenebeck	412	void Connect(Engine* pEngine);
196	schoenebeck	200
197			/**
198			* Disconnect given sampler engine from this audio output device.
199			* Removes given sampler engine reference from the Engines
200			* container of this audio device.
201			*
202	schoenebeck	412	* @param pEngine - sampler engine
203	schoenebeck	200	*/
204	schoenebeck	412	void Disconnect(Engine* pEngine);
205	schoenebeck	200
206			/**
207			* Returns audio channel with index \a ChannelIndex or NULL if
208			* index out of bounds.
209			*/
210			AudioChannel* Channel(uint ChannelIndex);
211
212	schoenebeck	221	/**
213	schoenebeck	226	* This method will usually be called by the sampler engines that
214			* are connected to this audio device to inform the audio device
215			* how much audio channels the engine(s) need. It's the
216			* responsibility of the audio device to offer that amount of
217			* audio channels - again: this is not an option this is a must!
218			* The engines will assume to be able to access those audio
219			* channels right after. If the audio driver is not able to offer
220			* that much channels, it can simply create mix channels which
221			* are then just mixed to the 'real' audio channels. See
222			* AudioChannel.h for details about channels and mix channels.
223			*
224			* @param Channels - amount of output channels required by
225			* a sampler engine
226			* @throws AudioOutputException if desired amount of channels
227			* cannot be offered
228			* @see AudioChannel
229			*/
230			void AcquireChannels(uint Channels);
231
232			/**
233	schoenebeck	221	* Returns all device parameter settings.
234			*/
235	schoenebeck	200	std::map<String,DeviceCreationParameter*> DeviceParameters();
236
237			protected:
238	persson	840	SynchronizedConfig<std::set<Engine*> > Engines; ///< All sampler engines that are connected to the audio output device.
239	persson	846	SynchronizedConfig<std::set<Engine*> >::Reader EnginesReader; ///< Audio thread access to Engines.
240	schoenebeck	200	std::vector<AudioChannel*> Channels; ///< All audio channels of the audio output device. This is just a container; the descendant has to create channels by himself.
241			std::map<String,DeviceCreationParameter*> Parameters; ///< All device parameters.
242
243			AudioOutputDevice(std::map<String,DeviceCreationParameter*> DriverParameters);
244
245			virtual ~AudioOutputDevice();
246
247			/**
248			* This method should be called by the AudioOutputDevice
249			* descendant to let all connected engines proceed to render the
250			* given amount of sample points. The engines will place their
251			* calculated audio data by themselfes into the buffers of the
252			* respective AudioChannel objects, so the implementing audio
253			* output device just has to copy the AudioChannel buffers to
254			* the output buffer(s) of its audio system.
255			*
256			* @returns 0 on success or the last error return code of one
257			* engine
258			*/
259			int RenderAudio(uint Samples);
260
261			/**
262			* This can be called as an alternative to RenderAudio() for
263			* just writing silence to the audio output buffers and not
264			* calling the connected sampler engines for rendering audio, so
265			* to provide a method to stop playback if the used audio output
266			* system doesn't provide a better way.
267			*
268			* @returns 0 on success
269			*/
270			int RenderSilence(uint Samples);
271
272			friend class Sampler; // allow Sampler class to destroy audio devices
273
274			};
275
276			/**
277			* Audio output exception that should be thrown by the AudioOutputDevice
278			* descendants in case initialization of the audio output system failed
279			* (which should be done in the constructor of the AudioOutputDevice
280			* descendant).
281			*/
282	schoenebeck	880	class AudioOutputException : public Exception {
283	schoenebeck	200	public:
284	schoenebeck	880	AudioOutputException(const std::string& msg) : Exception(msg) {}
285	schoenebeck	200	};
286			}
287
288			#endif // __LS_AUDIOOUTPUTDEVICE_H__