2 * Copyright (C) 2007 The Android Open Source Project
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
8 * http://www.apache.org/licenses/LICENSE-2.0
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
17 #ifndef ANDROID_AUDIO_HARDWARE_INTERFACE_H
18 #define ANDROID_AUDIO_HARDWARE_INTERFACE_H
21 #include <sys/types.h>
23 #include <utils/Errors.h>
24 #include <utils/Vector.h>
25 #include <utils/String16.h>
26 #include <utils/String8.h>
28 #include <media/IAudioFlinger.h>
29 #include "media/AudioSystem.h"
34 // ----------------------------------------------------------------------------
37 * AudioStreamOut is the abstraction interface for the audio output hardware.
39 * It provides information about various properties of the audio output hardware driver.
41 class AudioStreamOut {
43 virtual ~AudioStreamOut() = 0;
45 /** return audio sampling rate in hz - eg. 44100 */
46 virtual uint32_t sampleRate() const = 0;
48 /** returns size of output buffer - eg. 4800 */
49 virtual size_t bufferSize() const = 0;
52 * returns the output channel nask
54 virtual uint32_t channels() const = 0;
57 * return audio format in 8bit or 16bit PCM format -
58 * eg. AudioSystem:PCM_16_BIT
60 virtual int format() const = 0;
63 * return the frame size (number of bytes per sample).
65 uint32_t frameSize() const { return AudioSystem::popCount(channels())*((format()==AudioSystem::PCM_16_BIT)?sizeof(int16_t):sizeof(int8_t)); }
68 * return the audio hardware driver latency in milli seconds.
70 virtual uint32_t latency() const = 0;
73 * Use this method in situations where audio mixing is done in the
74 * hardware. This method serves as a direct interface with hardware,
75 * allowing you to directly set the volume as apposed to via the framework.
76 * This method might produce multiple PCM outputs or hardware accelerated
77 * codecs, such as MP3 or AAC.
79 virtual status_t setVolume(float left, float right) = 0;
81 /** write audio buffer to driver. Returns number of bytes written */
82 virtual ssize_t write(const void* buffer, size_t bytes) = 0;
85 * Put the audio hardware output into standby mode. Returns
86 * status based on include/utils/Errors.h
88 virtual status_t standby() = 0;
90 /** dump the state of the audio output device */
91 virtual status_t dump(int fd, const Vector<String16>& args) = 0;
93 // set/get audio output parameters. The function accepts a list of parameters
94 // key value pairs in the form: key1=value1;key2=value2;...
95 // Some keys are reserved for standard parameters (See AudioParameter class).
96 // If the implementation does not accept a parameter change while the output is
97 // active but the parameter is acceptable otherwise, it must return INVALID_OPERATION.
98 // The audio flinger will put the output in standby and then change the parameter value.
99 virtual status_t setParameters(const String8& keyValuePairs) = 0;
100 virtual String8 getParameters(const String8& keys) = 0;
104 * AudioStreamIn is the abstraction interface for the audio input hardware.
106 * It defines the various properties of the audio hardware input driver.
108 class AudioStreamIn {
110 virtual ~AudioStreamIn() = 0;
112 /** return audio sampling rate in hz - eg. 44100 */
113 virtual uint32_t sampleRate() const = 0;
115 /** return the input buffer size allowed by audio driver */
116 virtual size_t bufferSize() const = 0;
118 /** return input channel mask */
119 virtual uint32_t channels() const = 0;
122 * return audio format in 8bit or 16bit PCM format -
123 * eg. AudioSystem:PCM_16_BIT
125 virtual int format() const = 0;
128 * return the frame size (number of bytes per sample).
130 uint32_t frameSize() const { return AudioSystem::popCount(channels())*((format()==AudioSystem::PCM_16_BIT)?sizeof(int16_t):sizeof(int8_t)); }
132 /** set the input gain for the audio driver. This method is for
134 virtual status_t setGain(float gain) = 0;
136 /** read audio buffer in from audio driver */
137 virtual ssize_t read(void* buffer, ssize_t bytes) = 0;
139 /** dump the state of the audio input device */
140 virtual status_t dump(int fd, const Vector<String16>& args) = 0;
143 * Put the audio hardware input into standby mode. Returns
144 * status based on include/utils/Errors.h
146 virtual status_t standby() = 0;
148 // set/get audio input parameters. The function accepts a list of parameters
149 // key value pairs in the form: key1=value1;key2=value2;...
150 // Some keys are reserved for standard parameters (See AudioParameter class).
151 // If the implementation does not accept a parameter change while the output is
152 // active but the parameter is acceptable otherwise, it must return INVALID_OPERATION.
153 // The audio flinger will put the input in standby and then change the parameter value.
154 virtual status_t setParameters(const String8& keyValuePairs) = 0;
155 virtual String8 getParameters(const String8& keys) = 0;
159 * AudioHardwareInterface.h defines the interface to the audio hardware abstraction layer.
161 * The interface supports setting and getting parameters, selecting audio routing
162 * paths, and defining input and output streams.
164 * AudioFlinger initializes the audio hardware and immediately opens an output stream.
165 * You can set Audio routing to output to handset, speaker, Bluetooth, or a headset.
167 * The audio input stream is initialized when AudioFlinger is called to carry out
168 * a record operation.
170 class AudioHardwareInterface
173 virtual ~AudioHardwareInterface() {}
176 * check to see if the audio hardware interface has been initialized.
177 * return status based on values defined in include/utils/Errors.h
179 virtual status_t initCheck() = 0;
181 /** set the audio volume of a voice call. Range is between 0.0 and 1.0 */
182 virtual status_t setVoiceVolume(float volume) = 0;
185 * set the audio volume for all audio activities other than voice call.
186 * Range between 0.0 and 1.0. If any value other than NO_ERROR is returned,
187 * the software mixer will emulate this capability.
189 virtual status_t setMasterVolume(float volume) = 0;
192 * setMode is called when the audio mode changes. NORMAL mode is for
193 * standard audio playback, RINGTONE when a ringtone is playing, and IN_CALL
194 * when a call is in progress.
196 virtual status_t setMode(int mode) = 0;
199 virtual status_t setMicMute(bool state) = 0;
200 virtual status_t getMicMute(bool* state) = 0;
202 // set/get global audio parameters
203 virtual status_t setParameters(const String8& keyValuePairs) = 0;
204 virtual String8 getParameters(const String8& keys) = 0;
206 // Returns audio input buffer size according to parameters passed or 0 if one of the
207 // parameters is not supported
208 virtual size_t getInputBufferSize(uint32_t sampleRate, int format, int channelCount) = 0;
210 /** This method creates and opens the audio hardware output stream */
211 virtual AudioStreamOut* openOutputStream(
214 uint32_t *channels=0,
215 uint32_t *sampleRate=0,
216 status_t *status=0) = 0;
217 virtual void closeOutputStream(AudioStreamOut* out) = 0;
218 /** This method creates and opens the audio hardware input stream */
219 virtual AudioStreamIn* openInputStream(
223 uint32_t *sampleRate,
225 AudioSystem::audio_in_acoustics acoustics) = 0;
226 virtual void closeInputStream(AudioStreamIn* in) = 0;
228 /**This method dumps the state of the audio hardware */
229 virtual status_t dumpState(int fd, const Vector<String16>& args) = 0;
231 static AudioHardwareInterface* create();
235 virtual status_t dump(int fd, const Vector<String16>& args) = 0;
238 // ----------------------------------------------------------------------------
240 extern "C" AudioHardwareInterface* createAudioHardware(void);
242 }; // namespace android
244 #endif // ANDROID_AUDIO_HARDWARE_INTERFACE_H