drivers/audio/AudioOutputDevice.h

/***************************************************************************
 *                                                                         *
 *   LinuxSampler - modular, streaming capable sampler                     *
 *                                                                         *
 *   Copyright (C) 2003, 2004 by Benno Senoner and Christian Schoenebeck   *
 *   Copyright (C) 2005 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/LinuxSamplerException.h"
#include "../Device.h"
#include "../DeviceParameter.h"
#include "../../engines/common/EngineChannel.h"
#include "AudioChannel.h"

namespace LinuxSampler {

    // just symbol prototyping
    class EngineChannel;

    /** 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 (LinuxSamplerException);
                    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 (LinuxSamplerException);
                    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 (LinuxSamplerException);
                    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 pEngineChannel - sampler engine channel
             */
            void Connect(EngineChannel* pEngineChannel);

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

            /**
             * 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:
            std::set<EngineChannel*>                  EngineChannels; ///< All sampler engine channels that are connected to the audio output device.
            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 LinuxSamplerException {
        public:
            AudioOutputException(const std::string& msg) : LinuxSamplerException(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	411	* Copyright (C) 2005 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			#include "../../common/LinuxSamplerException.h"
34	schoenebeck	207	#include "../Device.h"
35	schoenebeck	200	#include "../DeviceParameter.h"
36	schoenebeck	411	#include "../../engines/common/EngineChannel.h"
37	schoenebeck	200	#include "AudioChannel.h"
38
39			namespace LinuxSampler {
40
41			// just symbol prototyping
42	schoenebeck	411	class EngineChannel;
43	schoenebeck	200
44			/** Abstract base class for audio output drivers in LinuxSampler
45			*
46			* This class will be derived by specialized classes which implement the
47			* connection to a specific audio output system (e.g. Alsa, Jack,
48			* CoreAudio).
49			*/
50	schoenebeck	207	class AudioOutputDevice : public Device {
51	schoenebeck	200	public:
52
53			/////////////////////////////////////////////////////////////////
54			// Device parameters
55
56	schoenebeck	221	/** Device Parameter 'ACTIVE'
57			*
58			* Used to activate / deactivate the audio output device.
59			*/
60	schoenebeck	200	class ParameterActive : public DeviceCreationParameterBool {
61			public:
62	schoenebeck	226	ParameterActive();
63			ParameterActive(String s);
64			virtual String Description();
65			virtual bool Fix();
66			virtual bool Mandatory();
67			virtual std::map<String,DeviceCreationParameter*> DependsAsParameters();
68			virtual optional<bool> DefaultAsBool(std::map<String,String> Parameters);
69			virtual void OnSetValue(bool b) throw (LinuxSamplerException);
70			static String Name();
71	schoenebeck	200	};
72
73	schoenebeck	221	/** Device Parameter 'SAMPLERATE'
74			*
75			* Used to set the sample rate of the audio output device.
76			*/
77	schoenebeck	200	class ParameterSampleRate : public DeviceCreationParameterInt {
78			public:
79	schoenebeck	226	ParameterSampleRate();
80			ParameterSampleRate(String s);
81			virtual String Description();
82			virtual bool Fix();
83			virtual bool Mandatory();
84			virtual std::map<String,DeviceCreationParameter*> DependsAsParameters();
85			virtual optional<int> DefaultAsInt(std::map<String,String> Parameters);
86			virtual optional<int> RangeMinAsInt(std::map<String,String> Parameters);
87			virtual optional<int> RangeMaxAsInt(std::map<String,String> Parameters);
88			virtual std::vector<int> PossibilitiesAsInt(std::map<String,String> Parameters);
89			virtual void OnSetValue(int i) throw (LinuxSamplerException);
90			static String Name();
91	schoenebeck	200	};
92
93	schoenebeck	221	/** Device Parameters 'CHANNELS'
94			*
95			* Used to increase / decrease the number of audio channels of
96			* audio output device.
97			*/
98	schoenebeck	200	class ParameterChannels : public DeviceCreationParameterInt {
99			public:
100	schoenebeck	226	ParameterChannels();
101			ParameterChannels(String s);
102			virtual String Description();
103			virtual bool Fix();
104			virtual bool Mandatory();
105			virtual std::map<String,DeviceCreationParameter*> DependsAsParameters();
106			virtual optional<int> DefaultAsInt(std::map<String,String> Parameters);
107			virtual optional<int> RangeMinAsInt(std::map<String,String> Parameters);
108			virtual optional<int> RangeMaxAsInt(std::map<String,String> Parameters);
109			virtual std::vector<int> PossibilitiesAsInt(std::map<String,String> Parameters);
110			virtual void OnSetValue(int i) throw (LinuxSamplerException);
111			static String Name();
112	schoenebeck	200	};
113
114
115	schoenebeck	221
116	schoenebeck	200	/////////////////////////////////////////////////////////////////
117			// abstract methods
118			// (these have to be implemented by the descendant)
119
120			/**
121			* Start playback of audio signal on the audio device. It's the
122			* responsibility of the implementing audio device to call the
123			* RenderAudio(uint Samples) method of all connected engines.
124			* This will cause the engines to continue to render 'Samples'
125			* number of audio sample points and the engines will
126			* automatically add their audio signals to the audio buffers of
127			* the audio channels of this audio device. So the implementing
128			* audio device just has to access the buffers of it's audio
129			* channels.
130			*
131			* @throws AudioOutputException if playback can not be started
132			* @see AudioChannel
133			*/
134			virtual void Play() = 0;
135
136			/**
137			* Returns true if the audio device is currently playing back.
138			*/
139			virtual bool IsPlaying() = 0;
140
141			/**
142			* Stop playback of audio signal on the audio device. The
143			* implementing audio device will stop calling the RenderAudio()
144			* method of all connected engines and close it's connection to
145			* audio output system.
146			*/
147			virtual void Stop() = 0;
148
149			/**
150			* Maximum amount of sample points the implementing audio
151			* device will ever demand the sampler engines to write in one
152			* fragment cycle / period. Simple audio device drivers usually
153			* have a fixed fragment size, so those devices just would return
154			* the fragment size in this method.
155			*
156			* @returns max. amount of sample points ever
157			*/
158			virtual uint MaxSamplesPerCycle() = 0;
159
160			/**
161			* Playback samplerate the audio device uses. The sampler engines
162			* currently assume this to be a constant value for the whole
163			* life time of an instance of the implementing audio device.
164			*
165			* @returns sample rate in Hz
166			*/
167			virtual uint SampleRate() = 0;
168
169			/**
170	schoenebeck	226	* Return the audio output device driver name.
171	schoenebeck	200	*/
172			virtual String Driver() = 0;
173
174	schoenebeck	226	/**
175			* Create new audio channel. This will be called by
176			* AcquireChannels(). Each driver must implement it.
177			*/
178			virtual AudioChannel* CreateChannel(uint ChannelNr) = 0;
179
180
181
182	schoenebeck	200	/////////////////////////////////////////////////////////////////
183			// normal methods
184			// (usually not to be overriden by descendant)
185
186			/**
187			* Connect given sampler engine to this audio output device. The
188			* engine will be added to the Engines container of this audio
189			* device and the engine will also automatically be informed
190			* about the connection.
191			*
192	schoenebeck	411	* @param pEngineChannel - sampler engine channel
193	schoenebeck	200	*/
194	schoenebeck	411	void Connect(EngineChannel* pEngineChannel);
195	schoenebeck	200
196			/**
197			* Disconnect given sampler engine from this audio output device.
198			* Removes given sampler engine reference from the Engines
199			* container of this audio device.
200			*
201	schoenebeck	411	* @param pEngineChannel - sampler engine channel
202	schoenebeck	200	*/
203	schoenebeck	411	void Disconnect(EngineChannel* pEngineChannel);
204	schoenebeck	200
205			/**
206			* Returns audio channel with index \a ChannelIndex or NULL if
207			* index out of bounds.
208			*/
209			AudioChannel* Channel(uint ChannelIndex);
210
211	schoenebeck	221	/**
212	schoenebeck	226	* This method will usually be called by the sampler engines that
213			* are connected to this audio device to inform the audio device
214			* how much audio channels the engine(s) need. It's the
215			* responsibility of the audio device to offer that amount of
216			* audio channels - again: this is not an option this is a must!
217			* The engines will assume to be able to access those audio
218			* channels right after. If the audio driver is not able to offer
219			* that much channels, it can simply create mix channels which
220			* are then just mixed to the 'real' audio channels. See
221			* AudioChannel.h for details about channels and mix channels.
222			*
223			* @param Channels - amount of output channels required by
224			* a sampler engine
225			* @throws AudioOutputException if desired amount of channels
226			* cannot be offered
227			* @see AudioChannel
228			*/
229			void AcquireChannels(uint Channels);
230
231			/**
232	schoenebeck	221	* Returns all device parameter settings.
233			*/
234	schoenebeck	200	std::map<String,DeviceCreationParameter*> DeviceParameters();
235
236			protected:
237	schoenebeck	411	std::set<EngineChannel*> EngineChannels; ///< All sampler engine channels that are connected to the audio output device.
238	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.
239			std::map<String,DeviceCreationParameter*> Parameters; ///< All device parameters.
240
241			AudioOutputDevice(std::map<String,DeviceCreationParameter*> DriverParameters);
242
243			virtual ~AudioOutputDevice();
244
245			/**
246			* This method should be called by the AudioOutputDevice
247			* descendant to let all connected engines proceed to render the
248			* given amount of sample points. The engines will place their
249			* calculated audio data by themselfes into the buffers of the
250			* respective AudioChannel objects, so the implementing audio
251			* output device just has to copy the AudioChannel buffers to
252			* the output buffer(s) of its audio system.
253			*
254			* @returns 0 on success or the last error return code of one
255			* engine
256			*/
257			int RenderAudio(uint Samples);
258
259			/**
260			* This can be called as an alternative to RenderAudio() for
261			* just writing silence to the audio output buffers and not
262			* calling the connected sampler engines for rendering audio, so
263			* to provide a method to stop playback if the used audio output
264			* system doesn't provide a better way.
265			*
266			* @returns 0 on success
267			*/
268			int RenderSilence(uint Samples);
269
270			friend class Sampler; // allow Sampler class to destroy audio devices
271
272			};
273
274			/**
275			* Audio output exception that should be thrown by the AudioOutputDevice
276			* descendants in case initialization of the audio output system failed
277			* (which should be done in the constructor of the AudioOutputDevice
278			* descendant).
279			*/
280			class AudioOutputException : public LinuxSamplerException {
281			public:
282			AudioOutputException(const std::string& msg) : LinuxSamplerException(msg) {}
283			};
284			}
285
286			#endif // __LS_AUDIOOUTPUTDEVICE_H__