drivers/audio/AudioOutputDevice.h

/***************************************************************************
 *                                                                         *
 *   LinuxSampler - modular, streaming capable sampler                     *
 *                                                                         *
 *   Copyright (C) 2003, 2004 by Benno Senoner and Christian Schoenebeck   *
 *   Copyright (C) 2005 - 2008 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/Engine.h"
#include "AudioChannel.h"
#include "../../common/SynchronizedConfig.h"
#include "../../effects/EffectChain.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 int              ValueAsInt();
                    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 the amount of audio channels (including the so called
             * "mix channels") the device is currently providing.
             */
            uint ChannelCount();

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

            /**
             * Add a chain of master effects to this AudioOutputDevice.
             * You actually have to add effects to that chain afterwards.
             */
            EffectChain* AddMasterEffectChain();

            /**
             * Remove the master effect chain given by @a iChain .
             *
             * @throws Exception - if given master effect chain doesn't exist
             */
            void RemoveMasterEffectChain(uint iChain) throw (Exception);

            /**
             * Returns master effect chain given by @a iChain or @c NULL if
             * there's no such effect chain.
             */
            EffectChain* MasterEffectChain(uint iChain) const;

            /**
             * Returns amount of master effect chains this AudioOutputDevice
             * currently provides.
             */
            uint MasterEffectChainCount() const;

        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.
            std::vector<EffectChain*>                 vEffectChains;

            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	1722	* Copyright (C) 2005 - 2008 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	890	#include "../../engines/Engine.h"
37	schoenebeck	200	#include "AudioChannel.h"
38	persson	840	#include "../../common/SynchronizedConfig.h"
39	schoenebeck	1722	#include "../../effects/EffectChain.h"
40	schoenebeck	200
41			namespace LinuxSampler {
42
43			// just symbol prototyping
44	schoenebeck	412	class Engine;
45	schoenebeck	200
46			/** Abstract base class for audio output drivers in LinuxSampler
47			*
48			* This class will be derived by specialized classes which implement the
49			* connection to a specific audio output system (e.g. Alsa, Jack,
50			* CoreAudio).
51			*/
52	schoenebeck	207	class AudioOutputDevice : public Device {
53	schoenebeck	200	public:
54
55			/////////////////////////////////////////////////////////////////
56			// Device parameters
57
58	schoenebeck	221	/** Device Parameter 'ACTIVE'
59			*
60			* Used to activate / deactivate the audio output device.
61			*/
62	schoenebeck	200	class ParameterActive : public DeviceCreationParameterBool {
63			public:
64	schoenebeck	226	ParameterActive();
65			ParameterActive(String s);
66			virtual String Description();
67			virtual bool Fix();
68			virtual bool Mandatory();
69			virtual std::map<String,DeviceCreationParameter*> DependsAsParameters();
70			virtual optional<bool> DefaultAsBool(std::map<String,String> Parameters);
71	schoenebeck	880	virtual void OnSetValue(bool b) throw (Exception);
72	schoenebeck	226	static String Name();
73	schoenebeck	200	};
74
75	schoenebeck	221	/** Device Parameter 'SAMPLERATE'
76			*
77			* Used to set the sample rate of the audio output device.
78			*/
79	schoenebeck	200	class ParameterSampleRate : public DeviceCreationParameterInt {
80			public:
81	schoenebeck	226	ParameterSampleRate();
82			ParameterSampleRate(String s);
83			virtual String Description();
84			virtual bool Fix();
85			virtual bool Mandatory();
86			virtual std::map<String,DeviceCreationParameter*> DependsAsParameters();
87			virtual optional<int> DefaultAsInt(std::map<String,String> Parameters);
88			virtual optional<int> RangeMinAsInt(std::map<String,String> Parameters);
89			virtual optional<int> RangeMaxAsInt(std::map<String,String> Parameters);
90			virtual std::vector<int> PossibilitiesAsInt(std::map<String,String> Parameters);
91	schoenebeck	1607	virtual int ValueAsInt();
92	schoenebeck	880	virtual void OnSetValue(int i) throw (Exception);
93	schoenebeck	226	static String Name();
94	schoenebeck	200	};
95
96	schoenebeck	221	/** Device Parameters 'CHANNELS'
97			*
98			* Used to increase / decrease the number of audio channels of
99			* audio output device.
100			*/
101	schoenebeck	200	class ParameterChannels : public DeviceCreationParameterInt {
102			public:
103	schoenebeck	226	ParameterChannels();
104			ParameterChannels(String s);
105			virtual String Description();
106			virtual bool Fix();
107			virtual bool Mandatory();
108			virtual std::map<String,DeviceCreationParameter*> DependsAsParameters();
109			virtual optional<int> DefaultAsInt(std::map<String,String> Parameters);
110			virtual optional<int> RangeMinAsInt(std::map<String,String> Parameters);
111			virtual optional<int> RangeMaxAsInt(std::map<String,String> Parameters);
112			virtual std::vector<int> PossibilitiesAsInt(std::map<String,String> Parameters);
113	schoenebeck	880	virtual void OnSetValue(int i) throw (Exception);
114	schoenebeck	226	static String Name();
115	schoenebeck	200	};
116
117
118	schoenebeck	221
119	schoenebeck	200	/////////////////////////////////////////////////////////////////
120			// abstract methods
121			// (these have to be implemented by the descendant)
122
123			/**
124			* Start playback of audio signal on the audio device. It's the
125			* responsibility of the implementing audio device to call the
126			* RenderAudio(uint Samples) method of all connected engines.
127			* This will cause the engines to continue to render 'Samples'
128			* number of audio sample points and the engines will
129			* automatically add their audio signals to the audio buffers of
130			* the audio channels of this audio device. So the implementing
131			* audio device just has to access the buffers of it's audio
132			* channels.
133			*
134			* @throws AudioOutputException if playback can not be started
135			* @see AudioChannel
136			*/
137			virtual void Play() = 0;
138
139			/**
140			* Returns true if the audio device is currently playing back.
141			*/
142			virtual bool IsPlaying() = 0;
143
144			/**
145			* Stop playback of audio signal on the audio device. The
146			* implementing audio device will stop calling the RenderAudio()
147			* method of all connected engines and close it's connection to
148			* audio output system.
149			*/
150			virtual void Stop() = 0;
151
152			/**
153			* Maximum amount of sample points the implementing audio
154			* device will ever demand the sampler engines to write in one
155			* fragment cycle / period. Simple audio device drivers usually
156			* have a fixed fragment size, so those devices just would return
157			* the fragment size in this method.
158			*
159			* @returns max. amount of sample points ever
160			*/
161			virtual uint MaxSamplesPerCycle() = 0;
162
163			/**
164			* Playback samplerate the audio device uses. The sampler engines
165			* currently assume this to be a constant value for the whole
166			* life time of an instance of the implementing audio device.
167			*
168			* @returns sample rate in Hz
169			*/
170			virtual uint SampleRate() = 0;
171
172			/**
173	schoenebeck	226	* Return the audio output device driver name.
174	schoenebeck	200	*/
175			virtual String Driver() = 0;
176
177	schoenebeck	226	/**
178			* Create new audio channel. This will be called by
179			* AcquireChannels(). Each driver must implement it.
180			*/
181			virtual AudioChannel* CreateChannel(uint ChannelNr) = 0;
182
183
184
185	schoenebeck	200	/////////////////////////////////////////////////////////////////
186			// normal methods
187			// (usually not to be overriden by descendant)
188
189			/**
190			* Connect given sampler engine to this audio output device. The
191			* engine will be added to the Engines container of this audio
192			* device and the engine will also automatically be informed
193			* about the connection.
194			*
195	schoenebeck	412	* @param pEngine - sampler engine
196	schoenebeck	200	*/
197	schoenebeck	412	void Connect(Engine* pEngine);
198	schoenebeck	200
199			/**
200			* Disconnect given sampler engine from this audio output device.
201			* Removes given sampler engine reference from the Engines
202			* container of this audio device.
203			*
204	schoenebeck	412	* @param pEngine - sampler engine
205	schoenebeck	200	*/
206	schoenebeck	412	void Disconnect(Engine* pEngine);
207	schoenebeck	200
208			/**
209			* Returns audio channel with index \a ChannelIndex or NULL if
210			* index out of bounds.
211			*/
212			AudioChannel* Channel(uint ChannelIndex);
213
214	schoenebeck	221	/**
215	schoenebeck	226	* This method will usually be called by the sampler engines that
216			* are connected to this audio device to inform the audio device
217			* how much audio channels the engine(s) need. It's the
218			* responsibility of the audio device to offer that amount of
219			* audio channels - again: this is not an option this is a must!
220			* The engines will assume to be able to access those audio
221			* channels right after. If the audio driver is not able to offer
222			* that much channels, it can simply create mix channels which
223			* are then just mixed to the 'real' audio channels. See
224			* AudioChannel.h for details about channels and mix channels.
225			*
226			* @param Channels - amount of output channels required by
227			* a sampler engine
228			* @throws AudioOutputException if desired amount of channels
229			* cannot be offered
230			* @see AudioChannel
231			*/
232			void AcquireChannels(uint Channels);
233
234			/**
235	schoenebeck	1001	* Returns the amount of audio channels (including the so called
236			* "mix channels") the device is currently providing.
237			*/
238			uint ChannelCount();
239
240			/**
241	schoenebeck	221	* Returns all device parameter settings.
242			*/
243	schoenebeck	200	std::map<String,DeviceCreationParameter*> DeviceParameters();
244
245	schoenebeck	1722	/**
246			* Add a chain of master effects to this AudioOutputDevice.
247			* You actually have to add effects to that chain afterwards.
248			*/
249			EffectChain* AddMasterEffectChain();
250
251			/**
252			* Remove the master effect chain given by @a iChain .
253			*
254			* @throws Exception - if given master effect chain doesn't exist
255			*/
256			void RemoveMasterEffectChain(uint iChain) throw (Exception);
257
258			/**
259			* Returns master effect chain given by @a iChain or @c NULL if
260			* there's no such effect chain.
261			*/
262			EffectChain* MasterEffectChain(uint iChain) const;
263
264			/**
265			* Returns amount of master effect chains this AudioOutputDevice
266			* currently provides.
267			*/
268			uint MasterEffectChainCount() const;
269
270	schoenebeck	200	protected:
271	persson	840	SynchronizedConfig<std::set<Engine*> > Engines; ///< All sampler engines that are connected to the audio output device.
272	persson	846	SynchronizedConfig<std::set<Engine*> >::Reader EnginesReader; ///< Audio thread access to Engines.
273	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.
274			std::map<String,DeviceCreationParameter*> Parameters; ///< All device parameters.
275	schoenebeck	1722	std::vector<EffectChain*> vEffectChains;
276	schoenebeck	200
277			AudioOutputDevice(std::map<String,DeviceCreationParameter*> DriverParameters);
278
279			virtual ~AudioOutputDevice();
280
281			/**
282			* This method should be called by the AudioOutputDevice
283			* descendant to let all connected engines proceed to render the
284			* given amount of sample points. The engines will place their
285			* calculated audio data by themselfes into the buffers of the
286			* respective AudioChannel objects, so the implementing audio
287			* output device just has to copy the AudioChannel buffers to
288			* the output buffer(s) of its audio system.
289			*
290			* @returns 0 on success or the last error return code of one
291			* engine
292			*/
293			int RenderAudio(uint Samples);
294
295			/**
296			* This can be called as an alternative to RenderAudio() for
297			* just writing silence to the audio output buffers and not
298			* calling the connected sampler engines for rendering audio, so
299			* to provide a method to stop playback if the used audio output
300			* system doesn't provide a better way.
301			*
302			* @returns 0 on success
303			*/
304			int RenderSilence(uint Samples);
305
306			friend class Sampler; // allow Sampler class to destroy audio devices
307
308			};
309
310			/**
311			* Audio output exception that should be thrown by the AudioOutputDevice
312			* descendants in case initialization of the audio output system failed
313			* (which should be done in the constructor of the AudioOutputDevice
314			* descendant).
315			*/
316	schoenebeck	880	class AudioOutputException : public Exception {
317	schoenebeck	200	public:
318	schoenebeck	880	AudioOutputException(const std::string& msg) : Exception(msg) {}
319	schoenebeck	200	};
320			}
321
322			#endif // __LS_AUDIOOUTPUTDEVICE_H__