drivers/audio/AudioOutputDevice.h

/***************************************************************************
 *                                                                         *
 *   LinuxSampler - modular, streaming capable sampler                     *
 *                                                                         *
 *   Copyright (C) 2003, 2004 by Benno Senoner and 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 "../InputOutputDevice.h"
#include "../DeviceParameter.h"
#include "../../engines/common/Engine.h"
#include "AudioChannel.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 InputOutputDevice {
        public:

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

            class ParameterActive : public DeviceCreationParameterBool {
                public:
                    ParameterActive( void ) : DeviceCreationParameterBool()                  { InitWithDefault();                                  }
                    ParameterActive( String s ) : DeviceCreationParameterBool(s)             {}
                    virtual String Description()                                             { return "Enable / disable device";                   }
                    virtual bool   Fix()                                                     { return false;                                       }
                    virtual bool   Mandatory()                                               { return false;                                       }
                    virtual std::map<String,DeviceCreationParameter*> DependsAsParameters()  { return std::map<String,DeviceCreationParameter*>(); }
                    virtual optional<bool> DefaultAsBool(std::map<String,String> Parameters) { return true;                                        }
                    virtual void OnSetValue(bool b) throw (LinuxSamplerException)            { if (b) ((AudioOutputDevice*)pDevice)->Play(); else ((AudioOutputDevice*)pDevice)->Stop();       }
                    static String Name( void ) { return "active"; }
            };

            class ParameterSampleRate : public DeviceCreationParameterInt {
                public:
                    ParameterSampleRate() : DeviceCreationParameterInt()                            { InitWithDefault();                                  }
                    ParameterSampleRate( String s ) : DeviceCreationParameterInt(s)                 {}
                    virtual String Description()                                                    { return "Output sample rate";                        }
                    virtual bool   Fix()                                                            { return true;                                        }
                    virtual bool   Mandatory()                                                      { return false;                                       }
                    virtual std::map<String,DeviceCreationParameter*> DependsAsParameters()         { return std::map<String,DeviceCreationParameter*>(); }
                    virtual optional<int>    DefaultAsInt(std::map<String,String> Parameters)       { return 44100;                                       }
                    virtual optional<int>    RangeMinAsInt(std::map<String,String> Parameters)      { return optional<int>::nothing;                      }
                    virtual optional<int>    RangeMaxAsInt(std::map<String,String> Parameters)      { return optional<int>::nothing;                      }
                    virtual std::vector<int> PossibilitiesAsInt(std::map<String,String> Parameters) { return std::vector<int>();                          }
                    virtual void             OnSetValue(int i) throw (LinuxSamplerException)        { /* cannot happen, as parameter is fix */            }
                    static String Name( void ) { return "samplerate"; }
            };

            class ParameterChannels : public DeviceCreationParameterInt {
                public:
                    ParameterChannels() : DeviceCreationParameterInt()                              { InitWithDefault();                                  }
                    ParameterChannels( String s ) : DeviceCreationParameterInt(s)                   {}
                    virtual String Description()                                                    { return "Number of output channels";                 }
                    virtual bool   Fix()                                                            { return false;                                       }
                    virtual bool   Mandatory()                                                      { return false;                                       }
                    virtual std::map<String,DeviceCreationParameter*> DependsAsParameters()         { return std::map<String,DeviceCreationParameter*>(); }
                    virtual optional<int>    DefaultAsInt(std::map<String,String> Parameters)       { return 2;                                           }
                    virtual optional<int>    RangeMinAsInt(std::map<String,String> Parameters)      { return optional<int>::nothing;                      }
                    virtual optional<int>    RangeMaxAsInt(std::map<String,String> Parameters)      { return optional<int>::nothing;                      }
                    virtual std::vector<int> PossibilitiesAsInt(std::map<String,String> Parameters) { return std::vector<int>();                          }
                    virtual void             OnSetValue(int i) throw (LinuxSamplerException)        { ((AudioOutputDevice*)pDevice)->AcquireChannels(i);    }
                    static String Name( void ) { return "channels"; }
            };


            /////////////////////////////////////////////////////////////////
            // 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;

            /**
             * 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
             */
            virtual void AcquireChannels(uint Channels) = 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 type name.
             */
            virtual String Driver() = 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);

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


        protected:
            std::set<Engine*>                         Engines;     ///< All sampler engines 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	/***************************************************************************
2	* *
3	* LinuxSampler - modular, streaming capable sampler *
4	* *
5	* Copyright (C) 2003, 2004 by Benno Senoner and Christian Schoenebeck *
6	* *
7	* This program is free software; you can redistribute it and/or modify *
8	* it under the terms of the GNU General Public License as published by *
9	* the Free Software Foundation; either version 2 of the License, or *
10	* (at your option) any later version. *
11	* *
12	* This program is distributed in the hope that it will be useful, *
13	* but WITHOUT ANY WARRANTY; without even the implied warranty of *
14	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the *
15	* GNU General Public License for more details. *
16	* *
17	* You should have received a copy of the GNU General Public License *
18	* along with this program; if not, write to the Free Software *
19	* Foundation, Inc., 59 Temple Place, Suite 330, Boston, *
20	* MA 02111-1307 USA *
21	***************************************************************************/
22
23	#ifndef __LS_AUDIOOUTPUTDEVICE_H__
24	#define __LS_AUDIOOUTPUTDEVICE_H__
25
26	#include <set>
27	#include <map>
28	#include <vector>
29	#include <stdexcept>
30
31	#include "../../common/global.h"
32	#include "../../common/LinuxSamplerException.h"
33	#include "../InputOutputDevice.h"
34	#include "../DeviceParameter.h"
35	#include "../../engines/common/Engine.h"
36	#include "AudioChannel.h"
37
38	namespace LinuxSampler {
39
40	// just symbol prototyping
41	class Engine;
42
43	/** Abstract base class for audio output drivers in LinuxSampler
44	*
45	* This class will be derived by specialized classes which implement the
46	* connection to a specific audio output system (e.g. Alsa, Jack,
47	* CoreAudio).
48	*/
49	class AudioOutputDevice : public InputOutputDevice {
50	public:
51
52	/////////////////////////////////////////////////////////////////
53	// Device parameters
54
55	class ParameterActive : public DeviceCreationParameterBool {
56	public:
57	ParameterActive( void ) : DeviceCreationParameterBool() { InitWithDefault(); }
58	ParameterActive( String s ) : DeviceCreationParameterBool(s) {}
59	virtual String Description() { return "Enable / disable device"; }
60	virtual bool Fix() { return false; }
61	virtual bool Mandatory() { return false; }
62	virtual std::map<String,DeviceCreationParameter> DependsAsParameters() { return std::map<String,DeviceCreationParameter>(); }
63	virtual optional<bool> DefaultAsBool(std::map<String,String> Parameters) { return true; }
64	virtual void OnSetValue(bool b) throw (LinuxSamplerException) { if (b) ((AudioOutputDevice)pDevice)->Play(); else ((AudioOutputDevice)pDevice)->Stop(); }
65	static String Name( void ) { return "active"; }
66	};
67
68	class ParameterSampleRate : public DeviceCreationParameterInt {
69	public:
70	ParameterSampleRate() : DeviceCreationParameterInt() { InitWithDefault(); }
71	ParameterSampleRate( String s ) : DeviceCreationParameterInt(s) {}
72	virtual String Description() { return "Output sample rate"; }
73	virtual bool Fix() { return true; }
74	virtual bool Mandatory() { return false; }
75	virtual std::map<String,DeviceCreationParameter> DependsAsParameters() { return std::map<String,DeviceCreationParameter>(); }
76	virtual optional<int> DefaultAsInt(std::map<String,String> Parameters) { return 44100; }
77	virtual optional<int> RangeMinAsInt(std::map<String,String> Parameters) { return optional<int>::nothing; }
78	virtual optional<int> RangeMaxAsInt(std::map<String,String> Parameters) { return optional<int>::nothing; }
79	virtual std::vector<int> PossibilitiesAsInt(std::map<String,String> Parameters) { return std::vector<int>(); }
80	virtual void OnSetValue(int i) throw (LinuxSamplerException) { /* cannot happen, as parameter is fix */ }
81	static String Name( void ) { return "samplerate"; }
82	};
83
84	class ParameterChannels : public DeviceCreationParameterInt {
85	public:
86	ParameterChannels() : DeviceCreationParameterInt() { InitWithDefault(); }
87	ParameterChannels( String s ) : DeviceCreationParameterInt(s) {}
88	virtual String Description() { return "Number of output channels"; }
89	virtual bool Fix() { return false; }
90	virtual bool Mandatory() { return false; }
91	virtual std::map<String,DeviceCreationParameter> DependsAsParameters() { return std::map<String,DeviceCreationParameter>(); }
92	virtual optional<int> DefaultAsInt(std::map<String,String> Parameters) { return 2; }
93	virtual optional<int> RangeMinAsInt(std::map<String,String> Parameters) { return optional<int>::nothing; }
94	virtual optional<int> RangeMaxAsInt(std::map<String,String> Parameters) { return optional<int>::nothing; }
95	virtual std::vector<int> PossibilitiesAsInt(std::map<String,String> Parameters) { return std::vector<int>(); }
96	virtual void OnSetValue(int i) throw (LinuxSamplerException) { ((AudioOutputDevice*)pDevice)->AcquireChannels(i); }
97	static String Name( void ) { return "channels"; }
98	};
99
100
101	/////////////////////////////////////////////////////////////////
102	// abstract methods
103	// (these have to be implemented by the descendant)
104
105	/**
106	* Start playback of audio signal on the audio device. It's the
107	* responsibility of the implementing audio device to call the
108	* RenderAudio(uint Samples) method of all connected engines.
109	* This will cause the engines to continue to render 'Samples'
110	* number of audio sample points and the engines will
111	* automatically add their audio signals to the audio buffers of
112	* the audio channels of this audio device. So the implementing
113	* audio device just has to access the buffers of it's audio
114	* channels.
115	*
116	* @throws AudioOutputException if playback can not be started
117	* @see AudioChannel
118	*/
119	virtual void Play() = 0;
120
121	/**
122	* Returns true if the audio device is currently playing back.
123	*/
124	virtual bool IsPlaying() = 0;
125
126	/**
127	* Stop playback of audio signal on the audio device. The
128	* implementing audio device will stop calling the RenderAudio()
129	* method of all connected engines and close it's connection to
130	* audio output system.
131	*/
132	virtual void Stop() = 0;
133
134	/**
135	* This method will usually be called by the sampler engines that
136	* are connected to this audio device to inform the audio device
137	* how much audio channels the engine(s) need. It's the
138	* responsibility of the audio device to offer that amount of
139	* audio channels - again: this is not an option this is a must!
140	* The engines will assume to be able to access those audio
141	* channels right after. If the audio driver is not able to offer
142	* that much channels, it can simply create mix channels which
143	* are then just mixed to the 'real' audio channels. See
144	* AudioChannel.h for details about channels and mix channels.
145	*
146	* @param Channels - amount of output channels required by
147	* a sampler engine
148	* @throws AudioOutputException if desired amount of channels
149	* cannot be offered
150	* @see AudioChannel
151	*/
152	virtual void AcquireChannels(uint Channels) = 0;
153
154	/**
155	* Maximum amount of sample points the implementing audio
156	* device will ever demand the sampler engines to write in one
157	* fragment cycle / period. Simple audio device drivers usually
158	* have a fixed fragment size, so those devices just would return
159	* the fragment size in this method.
160	*
161	* @returns max. amount of sample points ever
162	*/
163	virtual uint MaxSamplesPerCycle() = 0;
164
165	/**
166	* Playback samplerate the audio device uses. The sampler engines
167	* currently assume this to be a constant value for the whole
168	* life time of an instance of the implementing audio device.
169	*
170	* @returns sample rate in Hz
171	*/
172	virtual uint SampleRate() = 0;
173
174	/**
175	* Return the audio output device driver type name.
176	*/
177	virtual String Driver() = 0;
178
179	/////////////////////////////////////////////////////////////////
180	// normal methods
181	// (usually not to be overriden by descendant)
182
183	/**
184	* Connect given sampler engine to this audio output device. The
185	* engine will be added to the Engines container of this audio
186	* device and the engine will also automatically be informed
187	* about the connection.
188	*
189	* @param pEngine - sampler engine
190	*/
191	void Connect(Engine* pEngine);
192
193	/**
194	* Disconnect given sampler engine from this audio output device.
195	* Removes given sampler engine reference from the Engines
196	* container of this audio device.
197	*
198	* @param pEngine - sampler engine
199	*/
200	void Disconnect(Engine* pEngine);
201
202	/**
203	* Returns audio channel with index \a ChannelIndex or NULL if
204	* index out of bounds.
205	*/
206	AudioChannel* Channel(uint ChannelIndex);
207
208	std::map<String,DeviceCreationParameter*> DeviceParameters();
209
210
211	protected:
212	std::set<Engine*> Engines; ///< All sampler engines that are connected to the audio output device.
213	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.
214	std::map<String,DeviceCreationParameter*> Parameters; ///< All device parameters.
215
216	AudioOutputDevice(std::map<String,DeviceCreationParameter*> DriverParameters);
217
218	virtual ~AudioOutputDevice();
219
220	/**
221	* This method should be called by the AudioOutputDevice
222	* descendant to let all connected engines proceed to render the
223	* given amount of sample points. The engines will place their
224	* calculated audio data by themselfes into the buffers of the
225	* respective AudioChannel objects, so the implementing audio
226	* output device just has to copy the AudioChannel buffers to
227	* the output buffer(s) of its audio system.
228	*
229	* @returns 0 on success or the last error return code of one
230	* engine
231	*/
232	int RenderAudio(uint Samples);
233
234	/**
235	* This can be called as an alternative to RenderAudio() for
236	* just writing silence to the audio output buffers and not
237	* calling the connected sampler engines for rendering audio, so
238	* to provide a method to stop playback if the used audio output
239	* system doesn't provide a better way.
240	*
241	* @returns 0 on success
242	*/
243	int RenderSilence(uint Samples);
244
245	friend class Sampler; // allow Sampler class to destroy audio devices
246
247	};
248
249	/**
250	* Audio output exception that should be thrown by the AudioOutputDevice
251	* descendants in case initialization of the audio output system failed
252	* (which should be done in the constructor of the AudioOutputDevice
253	* descendant).
254	*/
255	class AudioOutputException : public LinuxSamplerException {
256	public:
257	AudioOutputException(const std::string& msg) : LinuxSamplerException(msg) {}
258	};
259	}
260
261	#endif // __LS_AUDIOOUTPUTDEVICE_H__