pebble/src/fw/drivers/mic.h
2025-01-27 11:38:16 -08:00

49 lines
1.9 KiB
C

/*
* Copyright 2024 Google LLC
*
* 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.
*/
#pragma once
#include <stdint.h>
#include <stddef.h>
#include <stdbool.h>
#define MIC_SAMPLE_RATE (16000) //!< Microphone audio data sample rate
#define MIC_DEFAULT_VOLUME (-1)
typedef const struct MicDevice MicDevice;
//! Microphone audio data handler callback. Called when buffer is full
typedef void (*MicDataHandlerCB)(int16_t *samples, size_t sample_count, void *context);
//! Initialize microphone driver. Should be called on boot
void mic_init(MicDevice *this);
//! Set the mic volume. This must be called afer mic_init, and not while the mic is running.
void mic_set_volume(MicDevice *this, uint16_t volume);
//! Start the microphone. The driver will fill the specified buffer with up to the specified size
//! each time it calls the audio data handler callback. audio_buffer_len should be specified as the
//! length of the buffer (number of 16-bit samples it can hold)
//! @return true if mic was started, false if mic was already running
bool mic_start(MicDevice *this, MicDataHandlerCB data_handler, void *context,
int16_t *audio_buffer, size_t audio_buffer_len);
//! Stop the microphone. If buffer is not full, the remaining samples will be abandoned. No more
//! callbacks will be executed nor data copied into the buffer after this returns
void mic_stop(MicDevice *this);
//! Indicates whether the mic is running
bool mic_is_running(MicDevice *this);