/* * Copyright (C) 2011 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_HAL_INTERFACE_H #define ANDROID_AUDIO_HAL_INTERFACE_H #include #include #include #include #include #include #include __BEGIN_DECLS /** * The id of this module */ #define AUDIO_HARDWARE_MODULE_ID "audio" /** * Name of the audio devices to open */ #define AUDIO_HARDWARE_INTERFACE "audio_hw_if" /**************************************/ /* standard audio parameters that the HAL may need to handle */ #define AUDIO_PARAMETER_STREAM_ROUTING "routing" #define AUDIO_PARAMETER_STREAM_FORMAT "format" #define AUDIO_PARAMETER_STREAM_CHANNELS "channels" #define AUDIO_PARAMETER_STREAM_FRAME_COUNT "frame_count" #define AUDIO_PARAMETER_STREAM_INPUT_SOURCE "input_source" /* common audio stream parameters and operations */ struct audio_stream { /** * sampling rate is in Hz - eg. 44100 */ uint32_t (*get_sample_rate)(const struct audio_stream *stream); /* currently unused - use set_parameters with key * AUDIO_PARAMETER_STREAM_SAMPLING_RATE */ int (*set_sample_rate)(struct audio_stream *stream, uint32_t rate); /** * size of output buffer in bytes - eg. 4800 */ size_t (*get_buffer_size)(const struct audio_stream *stream); /** * the channel mask - * e.g. AUDIO_CHANNEL_OUT_STEREO or AUDIO_CHANNEL_IN_STEREO */ uint32_t (*get_channels)(const struct audio_stream *stream); /** * audio format - eg. AUDIO_FORMAT_PCM_16_BIT */ int (*get_format)(const struct audio_stream *stream); /* currently unused - use set_parameters with key * AUDIO_PARAMETER_STREAM_FORMAT */ int (*set_format)(struct audio_stream *stream, int format); /** * Put the audio hardware input/output into standby mode. * Returns 0 on success and <0 on failure. */ int (*standby)(struct audio_stream *stream); /** dump the state of the audio input/output device */ int (*dump)(const struct audio_stream *stream, int fd); audio_devices_t (*get_device)(const struct audio_stream *stream); int (*set_device)(struct audio_stream *stream, audio_devices_t device); /** * set/get audio stream parameters. The function accepts a list of * parameter key value pairs in the form: key1=value1;key2=value2;... * * Some keys are reserved for standard parameters (See AudioParameter class) * * If the implementation does not accept a parameter change while * the output is active but the parameter is acceptable otherwise, it must * return -ENOSYS. * * The audio flinger will put the stream in standby and then change the * parameter value. */ int (*set_parameters)(struct audio_stream *stream, const char *kv_pairs); /* * Returns a pointer to a heap allocated string. The caller is responsible * for freeing the memory for it. */ char * (*get_parameters)(const struct audio_stream *stream, const char *keys); }; typedef struct audio_stream audio_stream_t; /** * audio_stream_out is the abstraction interface for the audio output hardware. * * It provides information about various properties of the audio output * hardware driver. */ struct audio_stream_out { struct audio_stream common; /** * return the audio hardware driver latency in milli seconds. */ uint32_t (*get_latency)(const struct audio_stream_out *stream); /** * 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. */ int (*set_volume)(struct audio_stream_out *stream, float left, float right); /** * write audio buffer to driver. Returns number of bytes written */ ssize_t (*write)(struct audio_stream_out *stream, const void* buffer, size_t bytes); /* return the number of audio frames written by the audio dsp to DAC since * the output has exited standby */ int (*get_render_position)(const struct audio_stream_out *stream, uint32_t *dsp_frames); }; typedef struct audio_stream_out audio_stream_out_t; struct audio_stream_in { struct audio_stream common; /** set the input gain for the audio driver. This method is for * for future use */ int (*set_gain)(struct audio_stream_in *stream, float gain); /** read audio buffer in from audio driver */ ssize_t (*read)(struct audio_stream_in *stream, void* buffer, size_t bytes); /** * Return the amount of input frames lost in the audio driver since the * last call of this function. * Audio driver is expected to reset the value to 0 and restart counting * upon returning the current value by this function call. * Such loss typically occurs when the user space process is blocked * longer than the capacity of audio driver buffers. * * Unit: the number of input audio frames */ uint32_t (*get_input_frames_lost)(struct audio_stream_in *stream); }; typedef struct audio_stream_in audio_stream_in_t; /** * return the frame size (number of bytes per sample). */ static inline uint32_t audio_stream_frame_size(struct audio_stream *s) { int chan_samp_sz; switch (s->get_format(s)) { case AUDIO_FORMAT_PCM_16_BIT: chan_samp_sz = sizeof(int16_t); break; case AUDIO_FORMAT_PCM_8_BIT: default: chan_samp_sz = sizeof(int8_t); break; } return popcount(s->get_channels(s)) * chan_samp_sz; } /**********************************************************************/ /** * Every hardware module must have a data structure named HAL_MODULE_INFO_SYM * and the fields of this data structure must begin with hw_module_t * followed by module specific information. */ struct audio_module { struct hw_module_t common; }; struct audio_hw_device { struct hw_device_t common; /** * used by audio flinger to enumerate what devices are supported by * each audio_hw_device implementation. * * Return value is a bitmask of 1 or more values of audio_devices_t */ uint32_t (*get_supported_devices)(const struct audio_hw_device *dev); /** * check to see if the audio hardware interface has been initialized. * returns 0 on success, -ENODEV on failure. */ int (*init_check)(const struct audio_hw_device *dev); /** set the audio volume of a voice call. Range is between 0.0 and 1.0 */ int (*set_voice_volume)(struct audio_hw_device *dev, float volume); /** * set the audio volume for all audio activities other than voice call. * Range between 0.0 and 1.0. If any value other than 0 is returned, * the software mixer will emulate this capability. */ int (*set_master_volume)(struct audio_hw_device *dev, float volume); /** * setMode is called when the audio mode changes. AUDIO_MODE_NORMAL mode * is for standard audio playback, AUDIO_MODE_RINGTONE when a ringtone is * playing, and AUDIO_MODE_IN_CALL when a call is in progress. */ int (*set_mode)(struct audio_hw_device *dev, int mode); /* mic mute */ int (*set_mic_mute)(struct audio_hw_device *dev, bool state); int (*get_mic_mute)(const struct audio_hw_device *dev, bool *state); /* set/get global audio parameters */ int (*set_parameters)(struct audio_hw_device *dev, const char *kv_pairs); /* * Returns a pointer to a heap allocated string. The caller is responsible * for freeing the memory for it. */ char * (*get_parameters)(const struct audio_hw_device *dev, const char *keys); /* Returns audio input buffer size according to parameters passed or * 0 if one of the parameters is not supported */ size_t (*get_input_buffer_size)(const struct audio_hw_device *dev, uint32_t sample_rate, int format, int channel_count); /** This method creates and opens the audio hardware output stream */ int (*open_output_stream)(struct audio_hw_device *dev, uint32_t devices, int *format, uint32_t *channels, uint32_t *sample_rate, struct audio_stream_out **out); void (*close_output_stream)(struct audio_hw_device *dev, struct audio_stream_out* out); /** This method creates and opens the audio hardware input stream */ int (*open_input_stream)(struct audio_hw_device *dev, uint32_t devices, int *format, uint32_t *channels, uint32_t *sample_rate, audio_in_acoustics_t acoustics, struct audio_stream_in **stream_in); void (*close_input_stream)(struct audio_hw_device *dev, struct audio_stream_in *in); /** This method dumps the state of the audio hardware */ int (*dump)(const struct audio_hw_device *dev, int fd); }; typedef struct audio_hw_device audio_hw_device_t; /** convenience API for opening and closing a supported device */ static inline int audio_hw_device_open(const struct hw_module_t* module, struct audio_hw_device** device) { return module->methods->open(module, AUDIO_HARDWARE_INTERFACE, (struct hw_device_t**)device); } static inline int audio_hw_device_close(struct audio_hw_device* device) { return device->common.close(&device->common); } __END_DECLS #endif // ANDROID_AUDIO_INTERFACE_H