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	/***************************************************************************
2	* *
3	* LinuxSampler - modular, streaming capable sampler *
4	* *
5	* Copyright (C) 2003, 2004 by Benno Senoner and Christian Schoenebeck *
6	* Copyright (C) 2005 - 2008 Christian Schoenebeck *
7	* *
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/Exception.h"
34	#include "../Device.h"
35	#include "../DeviceParameter.h"
36	#include "../../engines/Engine.h"
37	#include "AudioChannel.h"
38	#include "../../common/SynchronizedConfig.h"
39	#include "../../effects/EffectChain.h"
40
41	namespace LinuxSampler {
42
43	// just symbol prototyping
44	class Engine;
45
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	class AudioOutputDevice : public Device {
53	public:
54
55	/////////////////////////////////////////////////////////////////
56	// Device parameters
57
58	/** Device Parameter 'ACTIVE'
59	*
60	* Used to activate / deactivate the audio output device.
61	*/
62	class ParameterActive : public DeviceCreationParameterBool {
63	public:
64	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	virtual void OnSetValue(bool b) throw (Exception);
72	static String Name();
73	};
74
75	/** Device Parameter 'SAMPLERATE'
76	*
77	* Used to set the sample rate of the audio output device.
78	*/
79	class ParameterSampleRate : public DeviceCreationParameterInt {
80	public:
81	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	virtual int ValueAsInt();
92	virtual void OnSetValue(int i) throw (Exception);
93	static String Name();
94	};
95
96	/** Device Parameters 'CHANNELS'
97	*
98	* Used to increase / decrease the number of audio channels of
99	* audio output device.
100	*/
101	class ParameterChannels : public DeviceCreationParameterInt {
102	public:
103	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	virtual void OnSetValue(int i) throw (Exception);
114	static String Name();
115	};
116
117
118
119	/////////////////////////////////////////////////////////////////
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	* Return the audio output device driver name.
174	*/
175	virtual String Driver() = 0;
176
177	/**
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	/////////////////////////////////////////////////////////////////
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	* @param pEngine - sampler engine
196	*/
197	void Connect(Engine* pEngine);
198
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	* @param pEngine - sampler engine
205	*/
206	void Disconnect(Engine* pEngine);
207
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	/**
215	* 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	* 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	* Returns all device parameter settings.
242	*/
243	std::map<String,DeviceCreationParameter*> DeviceParameters();
244
245	/**
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	protected:
271	SynchronizedConfig<std::set<Engine*> > Engines; ///< All sampler engines that are connected to the audio output device.
272	SynchronizedConfig<std::set<Engine*> >::Reader EnginesReader; ///< Audio thread access to Engines.
273	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	std::vector<EffectChain*> vEffectChains;
276
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	class AudioOutputException : public Exception {
317	public:
318	AudioOutputException(const std::string& msg) : Exception(msg) {}
319	};
320	}
321
322	#endif // __LS_AUDIOOUTPUTDEVICE_H__