/* * Copyright (C) 2007 The Android Open Source Project * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ #ifndef ANDROID_AUDIO_HARDWARE_INTERFACE_H #define ANDROID_AUDIO_HARDWARE_INTERFACE_H #include #include #include #include #include #include #include "media/AudioSystem.h" namespace android { // ---------------------------------------------------------------------------- /** * This is the abstraction interface for the audio output hardware. It provides * information about various properties of the audio output hardware driver. */ class AudioStreamOut { public: virtual ~AudioStreamOut() = 0; /** return audio sampling rate in hz - eg. 44100 */ virtual uint32_t sampleRate() const = 0; /** returns size of output buffer - eg. 4800 */ virtual size_t bufferSize() const = 0; /** * return number of output audio channels. * Acceptable values are 1 (mono) or 2 (stereo) */ virtual int channelCount() const = 0; /** * return audio format in 8bit or 16bit PCM format - * eg. AudioSystem:PCM_16_BIT */ virtual int format() const = 0; /** * This method can be used in situations where audio mixing is done in the * hardware. It is a direct interface to the hardware to set the volume as * as opposed to controlling this via the framework. It could be multiple * PCM outputs or hardware accelerated codecs such as MP3 or AAC */ virtual status_t setVolume(float volume) = 0; /** write audio buffer to driver. Returns number of bytes written */ virtual ssize_t write(const void* buffer, size_t bytes) = 0; /** dump the state of the audio output device */ virtual status_t dump(int fd, const Vector& args) = 0; }; /** * This is the abstraction interface for the audio input hardware. It defines * the various properties of the audio hardware input driver. */ class AudioStreamIn { public: virtual ~AudioStreamIn() = 0; /** return the input buffer size allowed by audio driver */ virtual size_t bufferSize() const = 0; /** return the number of audio input channels */ virtual int channelCount() const = 0; /** * return audio format in 8bit or 16bit PCM format - * eg. AudioSystem:PCM_16_BIT */ virtual int format() const = 0; /** set the input gain for the audio driver. This method is for * for future use */ virtual status_t setGain(float gain) = 0; /** read audio buffer in from audio driver */ virtual ssize_t read(void* buffer, ssize_t bytes) = 0; /** dump the state of the audio input device */ virtual status_t dump(int fd, const Vector& args) = 0; }; /** * This defines the interface to the audio hardware abstraction layer. It * supports setting and getting parameters, selecting audio routing paths and * defining input and output streams. * * AudioFlinger initializes the audio hardware and immediately opens an output * stream. Audio routing can be set to output to handset, speaker, bluetooth or * headset. * * The audio input stream is initialized when AudioFlinger is called to carry * out a record operation. */ class AudioHardwareInterface { public: AudioHardwareInterface(); virtual ~AudioHardwareInterface() { } /** * check to see if the audio hardware interface has been initialized. * return status based on values defined in include/utils/Errors.h */ virtual status_t initCheck() = 0; /** * put the audio hardware into standby mode to conserve power. Returns * status based on include/utils/Errors.h */ virtual status_t standby() = 0; /** set the audio volume of a voice call. Range is between 0.0 and 1.0 */ virtual status_t setVoiceVolume(float volume) = 0; /** * set the audio volume for all audio activities other than voice call. * Range between 0.0 and 1.0. IF any value other than NO_ERROR is returned, * the software mixer will emulate this capability. */ virtual status_t setMasterVolume(float volume) = 0; /** * Audio routing methods. Routes defined in include/hardware/AudioSystem.h. * Audio routes can be (ROUTE_EARPIECE | ROUTE_SPEAKER | ROUTE_BLUETOOTH * | ROUTE_HEADSET) * * setRouting sets the routes for a mode. This is called at startup. It is * also called when a new device is connected, such as a wired headset is * plugged in or a Bluetooth headset is paired */ virtual status_t setRouting(int mode, uint32_t routes); virtual status_t getRouting(int mode, uint32_t* routes); /** * setMode is called when the audio mode changes. NORMAL mode is for * standard audio playback, RINGTONE when a ringtone is playing and IN_CALL * when a call is in progress. */ virtual status_t setMode(int mode); virtual status_t getMode(int* mode); // mic mute virtual status_t setMicMute(bool state) = 0; virtual status_t getMicMute(bool* state) = 0; // Temporary interface, do not use // TODO: Replace with a more generic key:value get/set mechanism virtual status_t setParameter(const char* key, const char* value); /** This method creates and opens the audio hardware output stream */ virtual AudioStreamOut* openOutputStream( int format=0, int channelCount=0, uint32_t sampleRate=0) = 0; /** This method creates and opens the audio hardware input stream */ virtual AudioStreamIn* openInputStream( int format, int channelCount, uint32_t sampleRate) = 0; /**This method dumps the state of the audio hardware */ virtual status_t dumpState(int fd, const Vector& args); static AudioHardwareInterface* create(); protected: /** * doRouting actually initiates the routing to occur. A call to setRouting * or setMode may result in a routing change. The generic logic will call * doRouting when required. If the device has any special requirements these * methods can be overriden. */ virtual status_t doRouting() = 0; virtual status_t dump(int fd, const Vector& args) = 0; int mMode; uint32_t mRoutes[AudioSystem::NUM_MODES]; }; // ---------------------------------------------------------------------------- extern "C" AudioHardwareInterface* createAudioHardware(void); }; // namespace android #endif // ANDROID_AUDIO_HARDWARE_INTERFACE_H