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/*************************************************************************** |
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* * |
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* LinuxSampler - modular, streaming capable sampler * |
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* * |
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* Copyright (C) 2003, 2004 by Benno Senoner and Christian Schoenebeck * |
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* Copyright (C) 2005 - 2010 Christian Schoenebeck * |
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* * |
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* This program is free software; you can redistribute it and/or modify * |
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* it under the terms of the GNU General Public License as published by * |
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* the Free Software Foundation; either version 2 of the License, or * |
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* (at your option) any later version. * |
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* * |
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* This program is distributed in the hope that it will be useful, * |
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* but WITHOUT ANY WARRANTY; without even the implied warranty of * |
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * |
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* GNU General Public License for more details. * |
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* * |
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* You should have received a copy of the GNU General Public License * |
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* along with this program; if not, write to the Free Software * |
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, * |
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* MA 02111-1307 USA * |
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***************************************************************************/ |
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|
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#ifndef __LS_AUDIOOUTPUTDEVICE_H__ |
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#define __LS_AUDIOOUTPUTDEVICE_H__ |
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|
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#include <set> |
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#include <map> |
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#include <vector> |
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#include <stdexcept> |
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|
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#include "../../common/global.h" |
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#include "../../common/Exception.h" |
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#include "../Device.h" |
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#include "../DeviceParameter.h" |
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#include "../../engines/Engine.h" |
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#include "AudioChannel.h" |
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#include "../../common/SynchronizedConfig.h" |
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#include "../../effects/EffectChain.h" |
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|
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namespace LinuxSampler { |
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|
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// just symbol prototyping |
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class Engine; |
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class AudioOutputDeviceFactory; |
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class IDGenerator; |
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|
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/** Abstract base class for audio output drivers in LinuxSampler |
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* |
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* This class will be derived by specialized classes which implement the |
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* connection to a specific audio output system (e.g. Alsa, Jack, |
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* CoreAudio). |
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*/ |
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class AudioOutputDevice : public Device { |
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public: |
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|
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///////////////////////////////////////////////////////////////// |
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// Device parameters |
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|
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/** Device Parameter 'ACTIVE' |
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* |
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* Used to activate / deactivate the audio output device. |
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*/ |
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class ParameterActive : public DeviceCreationParameterBool { |
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public: |
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ParameterActive(); |
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ParameterActive(String s); |
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virtual String Description(); |
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virtual bool Fix(); |
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virtual bool Mandatory(); |
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virtual std::map<String,DeviceCreationParameter*> DependsAsParameters(); |
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virtual optional<bool> DefaultAsBool(std::map<String,String> Parameters); |
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virtual void OnSetValue(bool b) throw (Exception); |
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static String Name(); |
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}; |
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|
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/** Device Parameter 'SAMPLERATE' |
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* |
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* Used to set the sample rate of the audio output device. |
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*/ |
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class ParameterSampleRate : public DeviceCreationParameterInt { |
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public: |
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ParameterSampleRate(); |
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ParameterSampleRate(String s); |
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virtual String Description(); |
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virtual bool Fix(); |
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virtual bool Mandatory(); |
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virtual std::map<String,DeviceCreationParameter*> DependsAsParameters(); |
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virtual optional<int> DefaultAsInt(std::map<String,String> Parameters); |
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virtual optional<int> RangeMinAsInt(std::map<String,String> Parameters); |
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virtual optional<int> RangeMaxAsInt(std::map<String,String> Parameters); |
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virtual std::vector<int> PossibilitiesAsInt(std::map<String,String> Parameters); |
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virtual int ValueAsInt(); |
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virtual void OnSetValue(int i) throw (Exception); |
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static String Name(); |
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}; |
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|
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/** Device Parameters 'CHANNELS' |
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* |
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* Used to increase / decrease the number of audio channels of |
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* audio output device. |
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*/ |
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class ParameterChannels : public DeviceCreationParameterInt { |
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public: |
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ParameterChannels(); |
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ParameterChannels(String s); |
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virtual String Description(); |
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virtual bool Fix(); |
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virtual bool Mandatory(); |
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virtual std::map<String,DeviceCreationParameter*> DependsAsParameters(); |
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virtual optional<int> DefaultAsInt(std::map<String,String> Parameters); |
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virtual optional<int> RangeMinAsInt(std::map<String,String> Parameters); |
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virtual optional<int> RangeMaxAsInt(std::map<String,String> Parameters); |
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virtual std::vector<int> PossibilitiesAsInt(std::map<String,String> Parameters); |
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virtual void OnSetValue(int i) throw (Exception); |
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static String Name(); |
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}; |
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|
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|
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|
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///////////////////////////////////////////////////////////////// |
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// abstract methods |
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// (these have to be implemented by the descendant) |
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|
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/** |
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* Start playback of audio signal on the audio device. It's the |
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* responsibility of the implementing audio device to call the |
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* RenderAudio(uint Samples) method of all connected engines. |
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* This will cause the engines to continue to render 'Samples' |
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* number of audio sample points and the engines will |
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* automatically add their audio signals to the audio buffers of |
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* the audio channels of this audio device. So the implementing |
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* audio device just has to access the buffers of it's audio |
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* channels. |
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* |
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* @throws AudioOutputException if playback can not be started |
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* @see AudioChannel |
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*/ |
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virtual void Play() = 0; |
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|
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/** |
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* Returns true if the audio device is currently playing back. |
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*/ |
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virtual bool IsPlaying() = 0; |
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|
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/** |
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* Stop playback of audio signal on the audio device. The |
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* implementing audio device will stop calling the RenderAudio() |
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* method of all connected engines and close it's connection to |
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* audio output system. |
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*/ |
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virtual void Stop() = 0; |
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|
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/** |
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* Maximum amount of sample points the implementing audio |
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* device will ever demand the sampler engines to write in one |
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* fragment cycle / period. Simple audio device drivers usually |
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* have a fixed fragment size, so those devices just would return |
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* the fragment size in this method. |
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* |
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* @returns max. amount of sample points ever |
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*/ |
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virtual uint MaxSamplesPerCycle() = 0; |
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|
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/** |
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* Playback samplerate the audio device uses. The sampler engines |
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* currently assume this to be a constant value for the whole |
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* life time of an instance of the implementing audio device. |
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* |
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* @returns sample rate in Hz |
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*/ |
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virtual uint SampleRate() = 0; |
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|
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/** |
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* Return the audio output device driver name. |
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*/ |
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virtual String Driver() = 0; |
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|
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/** |
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* Create new audio channel. This will be called by |
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* AcquireChannels(). Each driver must implement it. |
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*/ |
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virtual AudioChannel* CreateChannel(uint ChannelNr) = 0; |
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|
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/** |
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* Might be optionally implemented by the deriving driver. If |
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* implemented, this method will return the current audio |
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* latency in seconds. The driver might measure the actual |
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* latency with timing functions to return the real latency. |
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* |
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* If this method is not implemented / overridden by the |
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* descending driver, it will simply return the theoretical |
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* latency, that is MaxSamplesPerCycle() / SampleRate(). |
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* |
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* Currently this method is not used by the sampler itself. |
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* It can be used however for GUIs built on top of the sampler |
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* for example, to i.e. display the user the currently |
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* effective audio latency in real-time. |
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*/ |
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virtual float latency(); |
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|
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|
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|
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///////////////////////////////////////////////////////////////// |
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// normal methods |
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// (usually not to be overriden by descendant) |
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|
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/** |
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* Connect given sampler engine to this audio output device. The |
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* engine will be added to the Engines container of this audio |
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* device and the engine will also automatically be informed |
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* about the connection. |
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* |
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* @param pEngine - sampler engine |
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*/ |
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void Connect(Engine* pEngine); |
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|
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/** |
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* Disconnect given sampler engine from this audio output device. |
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* Removes given sampler engine reference from the Engines |
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* container of this audio device. |
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* |
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* @param pEngine - sampler engine |
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*/ |
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void Disconnect(Engine* pEngine); |
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|
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/** |
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* This method can or should be called by the deriving driver in |
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* case some fundamental parameter changed, especially if the |
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* values returned by MaxSamplesPerCycle() and SamplerRate() have |
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* changed, those are values which the sampler engines assume to be |
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* constant for the life time of an audio device ! |
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* |
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* By forcing a re-connection with this method, the sampler engines |
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* are forced to update those informations metntioned above as well, |
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* avoiding crashes or other undesired misbehaviors in such |
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* circumstances. |
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*/ |
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void ReconnectAll(); |
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|
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/** |
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* Returns audio channel with index \a ChannelIndex or NULL if |
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* index out of bounds. |
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*/ |
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AudioChannel* Channel(uint ChannelIndex); |
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|
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/** |
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* This method will usually be called by the sampler engines that |
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* are connected to this audio device to inform the audio device |
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* how much audio channels the engine(s) need. It's the |
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* responsibility of the audio device to offer that amount of |
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* audio channels - again: this is not an option this is a must! |
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* The engines will assume to be able to access those audio |
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* channels right after. If the audio driver is not able to offer |
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* that much channels, it can simply create mix channels which |
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* are then just mixed to the 'real' audio channels. See |
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* AudioChannel.h for details about channels and mix channels. |
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* |
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* @param Channels - amount of output channels required by |
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* a sampler engine |
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* @throws AudioOutputException if desired amount of channels |
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* cannot be offered |
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* @see AudioChannel |
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*/ |
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void AcquireChannels(uint Channels); |
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|
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/** |
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* Returns the amount of audio channels (including the so called |
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* "mix channels") the device is currently providing. |
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*/ |
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uint ChannelCount(); |
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|
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/** |
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* Returns all device parameter settings. |
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*/ |
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std::map<String,DeviceCreationParameter*> DeviceParameters(); |
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|
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/** |
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* Add a chain of send effects to this AudioOutputDevice. |
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* You actually have to add effects to that chain afterwards. |
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*/ |
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EffectChain* AddSendEffectChain(); |
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|
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/** |
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* Remove the send effect chain given by @a iChain . |
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* |
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* @throws Exception - if given send effect chain doesn't exist |
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*/ |
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void RemoveSendEffectChain(uint iChain) throw (Exception); |
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|
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/** |
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* Returns send effect chain given by @a iChain or @c NULL if |
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* there's no such effect chain. |
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*/ |
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EffectChain* SendEffectChain(uint iChain) const; |
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|
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/** |
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* Returns send effect chain with ID @a iChainID or @c NULL if |
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* there's no such effect chain. |
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*/ |
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EffectChain* SendEffectChainByID(uint iChainID) const; |
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|
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/** |
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* Returns amount of send effect chains this AudioOutputDevice |
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* currently provides. |
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*/ |
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uint SendEffectChainCount() const; |
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|
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/** |
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* @deprecated This method will be removed, use AddSendEffectChain() instead! |
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*/ |
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EffectChain* AddMasterEffectChain() DEPRECATED_API; |
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|
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/** |
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* @deprecated This method will be removed, use RemoveSendEffectChain() instead! |
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*/ |
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void RemoveMasterEffectChain(uint iChain) throw (Exception) DEPRECATED_API; |
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|
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/** |
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* @deprecated This method will be removed, use SendEffectChain() instead! |
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*/ |
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EffectChain* MasterEffectChain(uint iChain) const DEPRECATED_API; |
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|
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/** |
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* @deprecated This method will be removed, use SendEffectChainCount() instead! |
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*/ |
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uint MasterEffectChainCount() const DEPRECATED_API; |
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|
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protected: |
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SynchronizedConfig<std::set<Engine*> > Engines; ///< All sampler engines that are connected to the audio output device. |
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SynchronizedConfig<std::set<Engine*> >::Reader EnginesReader; ///< Audio thread access to Engines. |
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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. |
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std::map<String,DeviceCreationParameter*> Parameters; ///< All device parameters. |
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std::vector<EffectChain*> vEffectChains; |
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IDGenerator* EffectChainIDs; |
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|
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AudioOutputDevice(std::map<String,DeviceCreationParameter*> DriverParameters); |
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|
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virtual ~AudioOutputDevice(); |
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|
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/** |
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* This method should be called by the AudioOutputDevice |
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* descendant to let all connected engines proceed to render the |
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* given amount of sample points. The engines will place their |
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* calculated audio data by themselfes into the buffers of the |
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* respective AudioChannel objects, so the implementing audio |
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* output device just has to copy the AudioChannel buffers to |
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* the output buffer(s) of its audio system. |
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* |
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* @returns 0 on success or the last error return code of one |
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* engine |
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*/ |
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int RenderAudio(uint Samples); |
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|
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/** |
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* This can be called as an alternative to RenderAudio() for |
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* just writing silence to the audio output buffers and not |
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* calling the connected sampler engines for rendering audio, so |
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* to provide a method to stop playback if the used audio output |
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* system doesn't provide a better way. |
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* |
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* @returns 0 on success |
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*/ |
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int RenderSilence(uint Samples); |
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|
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friend class AudioOutputDeviceFactory; // allow AudioOutputDeviceFactory class to destroy audio devices |
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|
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}; |
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|
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/** |
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* Audio output exception that should be thrown by the AudioOutputDevice |
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* descendants in case initialization of the audio output system failed |
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* (which should be done in the constructor of the AudioOutputDevice |
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* descendant). |
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*/ |
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class AudioOutputException : public Exception { |
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public: |
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AudioOutputException(const std::string& msg) : Exception(msg) {} |
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}; |
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} |
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|
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#endif // __LS_AUDIOOUTPUTDEVICE_H__ |