diff options
Diffstat (limited to 'include/hardware/AudioHardwareInterface.h')
| -rw-r--r-- | include/hardware/AudioHardwareInterface.h | 173 |
1 files changed, 99 insertions, 74 deletions
diff --git a/include/hardware/AudioHardwareInterface.h b/include/hardware/AudioHardwareInterface.h index febc86a..66cf0ff 100644 --- a/include/hardware/AudioHardwareInterface.h +++ b/include/hardware/AudioHardwareInterface.h @@ -33,137 +33,159 @@ namespace android { // ---------------------------------------------------------------------------- /** - * This is the abstraction interface for the audio output hardware. It provides - * information about various properties of the audio output hardware driver. + * AudioStreamOut 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) + + /** + * 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 + * 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 + + /** + * return the frame size (number of bytes per sample). + */ + uint32_t frameSize() const { return channelCount()*((format()==AudioSystem::PCM_16_BIT)?sizeof(int16_t):sizeof(int8_t)); } + + /** + * return the audio hardware driver latency in milli seconds. + */ + virtual uint32_t latency() const = 0; + + /** + * Use this method in situations where audio mixing is done in the + * hardware. This method serves as a direct interface with hardware, + * allowing you to directly set the volume as apposed to via the framework. + * This method might produce 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<String16>& args) = 0; + virtual status_t dump(int fd, const Vector<String16>& args) = 0; }; /** - * This is the abstraction interface for the audio input hardware. It defines - * the various properties of the audio hardware input driver. + * AudioStreamIn 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 + + /** + * return audio format in 8bit or 16bit PCM format - + * eg. AudioSystem:PCM_16_BIT */ virtual int format() const = 0; + /** + * return the frame size (number of bytes per sample). + */ + uint32_t frameSize() const { return channelCount()*((format()==AudioSystem::PCM_16_BIT)?sizeof(int16_t):sizeof(int8_t)); } + /** 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<String16>& args) = 0; + + /** + * Put the audio hardware input into standby mode. Returns + * status based on include/utils/Errors.h + */ + virtual status_t standby() = 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. +/** + * AudioHardwareInterface.h defines the interface to the audio hardware abstraction layer. + * + * The interface 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. + * You can set Audio routing to output to handset, speaker, Bluetooth, or a headset. * - * The audio input stream is initialized when AudioFlinger is called to carry - * out a record operation. + * 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 + /** + * 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 + /** + * 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, + + /** + * 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 + /** + * 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 + * 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); - + virtual status_t setRouting(int mode, uint32_t routes) = 0; + + virtual status_t getRouting(int mode, uint32_t* routes) = 0; + /** * setMode is called when the audio mode changes. NORMAL mode is for - * standard audio playback, RINGTONE when a ringtone is playing and IN_CALL + * 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); + virtual status_t setMode(int mode) = 0; + virtual status_t getMode(int* mode) = 0; // mic mute virtual status_t setMicMute(bool state) = 0; @@ -171,38 +193,41 @@ public: // 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); + virtual status_t setParameter(const char* key, const char* value) = 0; + // Returns audio input buffer size according to parameters passed or 0 if one of the + // parameters is not supported + virtual size_t getInputBufferSize(uint32_t sampleRate, int format, int channelCount) = 0; + /** This method creates and opens the audio hardware output stream */ virtual AudioStreamOut* openOutputStream( int format=0, int channelCount=0, - uint32_t sampleRate=0) = 0; + uint32_t sampleRate=0, + status_t *status=0) = 0; /** This method creates and opens the audio hardware input stream */ virtual AudioStreamIn* openInputStream( int format, int channelCount, - uint32_t sampleRate) = 0; - + uint32_t sampleRate, + status_t *status) = 0; + /**This method dumps the state of the audio hardware */ - virtual status_t dumpState(int fd, const Vector<String16>& args); + virtual status_t dumpState(int fd, const Vector<String16>& args) = 0; 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 actually initiates the routing. A call to setRouting + * or setMode may result in a routing change. The generic logic calls * 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<String16>& args) = 0; - int mMode; - uint32_t mRoutes[AudioSystem::NUM_MODES]; + virtual status_t dump(int fd, const Vector<String16>& args) = 0; }; // ---------------------------------------------------------------------------- |