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 27 #include <media/IAudioFlinger.h> 28 #include "media/AudioSystem.h" 29 30 31 namespace android { 32 33 // ---------------------------------------------------------------------------- 34 35 /** 36 * AudioStreamOut is the abstraction interface for the audio output hardware. 37 * 38 * It provides information about various properties of the audio output hardware driver. 39 */ 40 class AudioStreamOut { 41 public: 42 virtual ~AudioStreamOut() = 0; 43 44 /** return audio sampling rate in hz - eg. 44100 */ 45 virtual uint32_t sampleRate() const = 0; 46 47 /** returns size of output buffer - eg. 4800 */ 48 virtual size_t bufferSize() const = 0; 49 50 /** 51 * return number of output audio channels. 52 * Acceptable values are 1 (mono) or 2 (stereo) 53 */ 54 virtual int channelCount() 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 channelCount()*((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 volume) = 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 94 /** 95 * AudioStreamIn is the abstraction interface for the audio input hardware. 96 * 97 * It defines the various properties of the audio hardware input driver. 98 */ 99 class AudioStreamIn { 100 public: 101 virtual ~AudioStreamIn() = 0; 102 103 /** return the input buffer size allowed by audio driver */ 104 virtual size_t bufferSize() const = 0; 105 106 /** return the number of audio input channels */ 107 virtual int channelCount() const = 0; 108 109 /** 110 * return audio format in 8bit or 16bit PCM format - 111 * eg. AudioSystem:PCM_16_BIT 112 */ 113 virtual int format() const = 0; 114 115 /** 116 * return the frame size (number of bytes per sample). 117 */ frameSize()118 uint32_t frameSize() const { return channelCount()*((format()==AudioSystem::PCM_16_BIT)?sizeof(int16_t):sizeof(int8_t)); } 119 120 /** set the input gain for the audio driver. This method is for 121 * for future use */ 122 virtual status_t setGain(float gain) = 0; 123 124 /** read audio buffer in from audio driver */ 125 virtual ssize_t read(void* buffer, ssize_t bytes) = 0; 126 127 /** dump the state of the audio input device */ 128 virtual status_t dump(int fd, const Vector<String16>& args) = 0; 129 130 /** 131 * Put the audio hardware input into standby mode. Returns 132 * status based on include/utils/Errors.h 133 */ 134 virtual status_t standby() = 0; 135 136 }; 137 138 /** 139 * AudioHardwareInterface.h defines the interface to the audio hardware abstraction layer. 140 * 141 * The interface supports setting and getting parameters, selecting audio routing 142 * paths, and defining input and output streams. 143 * 144 * AudioFlinger initializes the audio hardware and immediately opens an output stream. 145 * You can set Audio routing to output to handset, speaker, Bluetooth, or a headset. 146 * 147 * The audio input stream is initialized when AudioFlinger is called to carry out 148 * a record operation. 149 */ 150 class AudioHardwareInterface 151 { 152 public: ~AudioHardwareInterface()153 virtual ~AudioHardwareInterface() {} 154 155 /** 156 * check to see if the audio hardware interface has been initialized. 157 * return status based on values defined in include/utils/Errors.h 158 */ 159 virtual status_t initCheck() = 0; 160 161 /** set the audio volume of a voice call. Range is between 0.0 and 1.0 */ 162 virtual status_t setVoiceVolume(float volume) = 0; 163 164 /** 165 * set the audio volume for all audio activities other than voice call. 166 * Range between 0.0 and 1.0. If any value other than NO_ERROR is returned, 167 * the software mixer will emulate this capability. 168 */ 169 virtual status_t setMasterVolume(float volume) = 0; 170 171 /** 172 * Audio routing methods. Routes defined in include/hardware_legacy/AudioSystem.h. 173 * Audio routes can be (ROUTE_EARPIECE | ROUTE_SPEAKER | ROUTE_BLUETOOTH 174 * | ROUTE_HEADSET) 175 * 176 * setRouting sets the routes for a mode. This is called at startup. It is 177 * also called when a new device is connected, such as a wired headset is 178 * plugged in or a Bluetooth headset is paired. 179 */ 180 virtual status_t setRouting(int mode, uint32_t routes) = 0; 181 182 virtual status_t getRouting(int mode, uint32_t* routes) = 0; 183 184 /** 185 * setMode is called when the audio mode changes. NORMAL mode is for 186 * standard audio playback, RINGTONE when a ringtone is playing, and IN_CALL 187 * when a call is in progress. 188 */ 189 virtual status_t setMode(int mode) = 0; 190 virtual status_t getMode(int* mode) = 0; 191 192 // mic mute 193 virtual status_t setMicMute(bool state) = 0; 194 virtual status_t getMicMute(bool* state) = 0; 195 196 // Temporary interface, do not use 197 // TODO: Replace with a more generic key:value get/set mechanism 198 virtual status_t setParameter(const char* key, const char* value) = 0; 199 200 // Returns audio input buffer size according to parameters passed or 0 if one of the 201 // parameters is not supported 202 virtual size_t getInputBufferSize(uint32_t sampleRate, int format, int channelCount) = 0; 203 204 /** This method creates and opens the audio hardware output stream */ 205 virtual AudioStreamOut* openOutputStream( 206 int format=0, 207 int channelCount=0, 208 uint32_t sampleRate=0, 209 status_t *status=0) = 0; 210 211 /** This method creates and opens the audio hardware input stream */ 212 virtual AudioStreamIn* openInputStream( 213 int inputSource, 214 int format, 215 int channelCount, 216 uint32_t sampleRate, 217 status_t *status, 218 AudioSystem::audio_in_acoustics acoustics) = 0; 219 220 /**This method dumps the state of the audio hardware */ 221 virtual status_t dumpState(int fd, const Vector<String16>& args) = 0; 222 223 static AudioHardwareInterface* create(); 224 225 protected: 226 /** 227 * doRouting actually initiates the routing. A call to setRouting 228 * or setMode may result in a routing change. The generic logic calls 229 * doRouting when required. If the device has any special requirements these 230 * methods can be overriden. 231 */ 232 virtual status_t doRouting() = 0; 233 234 virtual status_t dump(int fd, const Vector<String16>& args) = 0; 235 }; 236 237 // ---------------------------------------------------------------------------- 238 239 extern "C" AudioHardwareInterface* createAudioHardware(void); 240 241 }; // namespace android 242 243 #endif // ANDROID_AUDIO_HARDWARE_INTERFACE_H 244