1 /* 2 * Copyright (C) 2007 The Android Open Source Project 3 * 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 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 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. 15 */ 16 17 #ifndef ANDROID_AUDIO_HARDWARE_INTERFACE_H 18 #define ANDROID_AUDIO_HARDWARE_INTERFACE_H 19 20 #include <stdint.h> 21 #include <sys/types.h> 22 23 #include <utils/Errors.h> 24 #include <utils/Vector.h> 25 #include <utils/String16.h> 26 #include <utils/String8.h> 27 28 #include <media/IAudioFlinger.h> 29 #include "media/AudioSystem.h" 30 31 32 namespace android { 33 34 // ---------------------------------------------------------------------------- 35 36 /** 37 * AudioStreamOut is the abstraction interface for the audio output hardware. 38 * 39 * It provides information about various properties of the audio output hardware driver. 40 */ 41 class AudioStreamOut { 42 public: 43 virtual ~AudioStreamOut() = 0; 44 45 /** return audio sampling rate in hz - eg. 44100 */ 46 virtual uint32_t sampleRate() const = 0; 47 48 /** returns size of output buffer - eg. 4800 */ 49 virtual size_t bufferSize() const = 0; 50 51 /** 52 * returns the output channel nask 53 */ 54 virtual uint32_t channels() const = 0; 55 56 /** 57 * return audio format in 8bit or 16bit PCM format - 58 * eg. AudioSystem:PCM_16_BIT 59 */ 60 virtual int format() const = 0; 61 62 /** 63 * return the frame size (number of bytes per sample). 64 */ frameSize()65 uint32_t frameSize() const { return AudioSystem::popCount(channels())*((format()==AudioSystem::PCM_16_BIT)?sizeof(int16_t):sizeof(int8_t)); } 66 67 /** 68 * return the audio hardware driver latency in milli seconds. 69 */ 70 virtual uint32_t latency() const = 0; 71 72 /** 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. 78 */ 79 virtual status_t setVolume(float left, float right) = 0; 80 81 /** write audio buffer to driver. Returns number of bytes written */ 82 virtual ssize_t write(const void* buffer, size_t bytes) = 0; 83 84 /** 85 * Put the audio hardware output into standby mode. Returns 86 * status based on include/utils/Errors.h 87 */ 88 virtual status_t standby() = 0; 89 90 /** dump the state of the audio output device */ 91 virtual status_t dump(int fd, const Vector<String16>& args) = 0; 92 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; 101 }; 102 103 /** 104 * AudioStreamIn is the abstraction interface for the audio input hardware. 105 * 106 * It defines the various properties of the audio hardware input driver. 107 */ 108 class AudioStreamIn { 109 public: 110 virtual ~AudioStreamIn() = 0; 111 112 /** return audio sampling rate in hz - eg. 44100 */ 113 virtual uint32_t sampleRate() const = 0; 114 115 /** return the input buffer size allowed by audio driver */ 116 virtual size_t bufferSize() const = 0; 117 118 /** return input channel mask */ 119 virtual uint32_t channels() const = 0; 120 121 /** 122 * return audio format in 8bit or 16bit PCM format - 123 * eg. AudioSystem:PCM_16_BIT 124 */ 125 virtual int format() const = 0; 126 127 /** 128 * return the frame size (number of bytes per sample). 129 */ frameSize()130 uint32_t frameSize() const { return AudioSystem::popCount(channels())*((format()==AudioSystem::PCM_16_BIT)?sizeof(int16_t):sizeof(int8_t)); } 131 132 /** set the input gain for the audio driver. This method is for 133 * for future use */ 134 virtual status_t setGain(float gain) = 0; 135 136 /** read audio buffer in from audio driver */ 137 virtual ssize_t read(void* buffer, ssize_t bytes) = 0; 138 139 /** dump the state of the audio input device */ 140 virtual status_t dump(int fd, const Vector<String16>& args) = 0; 141 142 /** 143 * Put the audio hardware input into standby mode. Returns 144 * status based on include/utils/Errors.h 145 */ 146 virtual status_t standby() = 0; 147 148 // 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; 156 }; 157 158 /** 159 * AudioHardwareInterface.h defines the interface to the audio hardware abstraction layer. 160 * 161 * The interface supports setting and getting parameters, selecting audio routing 162 * paths, and defining input and output streams. 163 * 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. 166 * 167 * The audio input stream is initialized when AudioFlinger is called to carry out 168 * a record operation. 169 */ 170 class AudioHardwareInterface 171 { 172 public: ~AudioHardwareInterface()173 virtual ~AudioHardwareInterface() {} 174 175 /** 176 * check to see if the audio hardware interface has been initialized. 177 * return status based on values defined in include/utils/Errors.h 178 */ 179 virtual status_t initCheck() = 0; 180 181 /** set the audio volume of a voice call. Range is between 0.0 and 1.0 */ 182 virtual status_t setVoiceVolume(float volume) = 0; 183 184 /** 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. 188 */ 189 virtual status_t setMasterVolume(float volume) = 0; 190 191 /** 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. 195 */ 196 virtual status_t setMode(int mode) = 0; 197 198 // mic mute 199 virtual status_t setMicMute(bool state) = 0; 200 virtual status_t getMicMute(bool* state) = 0; 201 202 // set/get global audio parameters 203 virtual status_t setParameters(const String8& keyValuePairs) = 0; 204 virtual String8 getParameters(const String8& keys) = 0; 205 206 // 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; 209 210 /** This method creates and opens the audio hardware output stream */ 211 virtual AudioStreamOut* openOutputStream( 212 uint32_t devices, 213 int *format=0, 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( 220 uint32_t devices, 221 int *format, 222 uint32_t *channels, 223 uint32_t *sampleRate, 224 status_t *status, 225 AudioSystem::audio_in_acoustics acoustics) = 0; 226 virtual void closeInputStream(AudioStreamIn* in) = 0; 227 228 /**This method dumps the state of the audio hardware */ 229 virtual status_t dumpState(int fd, const Vector<String16>& args) = 0; 230 231 static AudioHardwareInterface* create(); 232 233 protected: 234 235 virtual status_t dump(int fd, const Vector<String16>& args) = 0; 236 }; 237 238 // ---------------------------------------------------------------------------- 239 240 extern "C" AudioHardwareInterface* createAudioHardware(void); 241 242 }; // namespace android 243 244 #endif // ANDROID_AUDIO_HARDWARE_INTERFACE_H 245