Audio HAL
Abstraction layer for audio board hardware, serves as an interface between the user application and the hardware driver for specific audio board like ESP32 LyraT.
The API provides data structures to configure sampling rates of ADC and DAC signal conversion, data bit widths, I2C stream parameters, and selection of signal channels connected to ADC and DAC. It also contains several specific functions to e.g. initialize the audio board, audio_hal_init()
, control the volume, audio_hal_get_volume()
and audio_hal_set_volume()
.
API Reference
Header File
Functions
-
audio_hal_handle_t audio_hal_init(audio_hal_codec_config_t *audio_hal_conf, audio_hal_func_t *audio_hal_func)
Initialize media codec driver.
备注
If selected codec has already been installed, it’ll return the audio_hal handle.
- 参数
audio_hal_conf – Configure structure audio_hal_config_t
audio_hal_func – Structure containing functions used to operate audio the codec chip
- 返回
int, 0—success, others—fail
-
esp_err_t audio_hal_deinit(audio_hal_handle_t audio_hal)
Uninitialize media codec driver.
- 参数
audio_hal – reference function pointer for selected audio codec
- 返回
int, 0—success, others—fail
-
esp_err_t audio_hal_ctrl_codec(audio_hal_handle_t audio_hal, audio_hal_codec_mode_t mode, audio_hal_ctrl_t audio_hal_ctrl)
Start/stop codec driver.
- 参数
audio_hal – reference function pointer for selected audio codec
mode – select media hal codec mode either encode/decode/or both to start from audio_hal_codec_mode_t
audio_hal_ctrl – select start stop state for specific mode
- 返回
int, 0—success, others—fail
-
esp_err_t audio_hal_codec_iface_config(audio_hal_handle_t audio_hal, audio_hal_codec_mode_t mode, audio_hal_codec_i2s_iface_t *iface)
Set codec I2S interface samples rate & bit width and format either I2S or PCM/DSP.
- 参数
audio_hal – reference function pointer for selected audio codec
mode – select media hal codec mode either encode/decode/or both to start from audio_hal_codec_mode_t
iface – I2S sample rate (ex: 16000, 44100), I2S bit width (16, 24, 32),I2s format (I2S, PCM, DSP).
- 返回
0 Success
-1 Error
-
esp_err_t audio_hal_set_mute(audio_hal_handle_t audio_hal, bool mute)
Set voice mute. Enables or disables DAC mute of a codec.
备注
audio_hal_get_volume
will still give a non-zero number in mute state. It will be set to that number when speaker is unmuted.- 参数
audio_hal – reference function pointer for selected audio codec
mute – true/false. If true speaker will be muted and if false speaker will be unmuted.
- 返回
int, 0—success, others—fail
-
esp_err_t audio_hal_set_volume(audio_hal_handle_t audio_hal, int volume)
Set voice volume.
备注
if volume is 0, mute is enabled,range is 0-100.
- 参数
audio_hal – reference function pointer for selected audio codec
volume – value of volume in percent(%)
- 返回
int, 0—success, others—fail
-
esp_err_t audio_hal_get_volume(audio_hal_handle_t audio_hal, int *volume)
get voice volume.
备注
if volume is 0, mute is enabled, range is 0-100.
- 参数
audio_hal – reference function pointer for selected audio codec
volume – value of volume in percent returned(%)
- 返回
int, 0—success, others—fail
-
esp_err_t audio_hal_enable_pa(audio_hal_handle_t audio_hal, bool enable)
Enables or disables PA.
- 参数
audio_hal – reference function pointer for selected audio codec
enable – true/false.
- 返回
int, 0—success, others—fail
Structures
-
struct audio_hal_codec_i2s_iface_t
I2s interface configuration for audio codec chip.
Public Members
-
audio_hal_iface_mode_t mode
audio codec chip mode
-
audio_hal_iface_format_t fmt
I2S interface format
-
audio_hal_iface_samples_t samples
I2S interface samples per second
-
audio_hal_iface_bits_t bits
i2s interface number of bits per sample
-
audio_hal_iface_mode_t mode
-
struct audio_hal_codec_config_t
Configure media hal for initialization of audio codec chip.
Public Members
-
audio_hal_adc_input_t adc_input
set adc channel
-
audio_hal_dac_output_t dac_output
set dac channel
-
audio_hal_codec_mode_t codec_mode
select codec mode: adc, dac or both
-
audio_hal_codec_i2s_iface_t i2s_iface
set I2S interface configuration
-
audio_hal_adc_input_t adc_input
-
struct audio_hal
Configuration of functions and variables used to operate audio codec chip.
Public Members
-
esp_err_t (*audio_codec_initialize)(audio_hal_codec_config_t *codec_cfg)
initialize codec
-
esp_err_t (*audio_codec_deinitialize)(void)
deinitialize codec
-
esp_err_t (*audio_codec_ctrl)(audio_hal_codec_mode_t mode, audio_hal_ctrl_t ctrl_state)
control codec mode and state
-
esp_err_t (*audio_codec_config_iface)(audio_hal_codec_mode_t mode, audio_hal_codec_i2s_iface_t *iface)
configure i2s interface
-
esp_err_t (*audio_codec_set_mute)(bool mute)
set codec mute
-
esp_err_t (*audio_codec_set_volume)(int volume)
set codec volume
-
esp_err_t (*audio_codec_get_volume)(int *volume)
get codec volume
-
esp_err_t (*audio_codec_enable_pa)(bool enable)
enable pa
-
xSemaphoreHandle audio_hal_lock
semaphore of codec
-
void *handle
handle of audio codec
-
esp_err_t (*audio_codec_initialize)(audio_hal_codec_config_t *codec_cfg)
Macros
-
AUDIO_HAL_VOL_DEFAULT
Type Definitions
Enumerations
-
enum audio_hal_codec_mode_t
Select media hal codec mode.
Values:
-
enumerator AUDIO_HAL_CODEC_MODE_ENCODE
select adc
-
enumerator AUDIO_HAL_CODEC_MODE_DECODE
select dac
-
enumerator AUDIO_HAL_CODEC_MODE_BOTH
select both adc and dac
-
enumerator AUDIO_HAL_CODEC_MODE_LINE_IN
set adc channel
-
enumerator AUDIO_HAL_CODEC_MODE_ENCODE
-
enum audio_hal_adc_input_t
Select adc channel for input mic signal.
Values:
-
enumerator AUDIO_HAL_ADC_INPUT_LINE1
mic input to adc channel 1
-
enumerator AUDIO_HAL_ADC_INPUT_LINE2
mic input to adc channel 2
-
enumerator AUDIO_HAL_ADC_INPUT_ALL
mic input to both channels of adc
-
enumerator AUDIO_HAL_ADC_INPUT_DIFFERENCE
mic input to adc difference channel
-
enumerator AUDIO_HAL_ADC_INPUT_LINE1
-
enum audio_hal_dac_output_t
Select channel for dac output.
Values:
-
enumerator AUDIO_HAL_DAC_OUTPUT_LINE1
dac output signal to channel 1
-
enumerator AUDIO_HAL_DAC_OUTPUT_LINE2
dac output signal to channel 2
-
enumerator AUDIO_HAL_DAC_OUTPUT_ALL
dac output signal to both channels
-
enumerator AUDIO_HAL_DAC_OUTPUT_LINE1
-
enum audio_hal_ctrl_t
Select operating mode i.e. start or stop for audio codec chip.
Values:
-
enumerator AUDIO_HAL_CTRL_STOP
set stop mode
-
enumerator AUDIO_HAL_CTRL_START
set start mode
-
enumerator AUDIO_HAL_CTRL_STOP
-
enum audio_hal_iface_mode_t
Select I2S interface operating mode i.e. master or slave for audio codec chip.
Values:
-
enumerator AUDIO_HAL_MODE_SLAVE
set slave mode
-
enumerator AUDIO_HAL_MODE_MASTER
set master mode
-
enumerator AUDIO_HAL_MODE_SLAVE
-
enum audio_hal_iface_samples_t
Select I2S interface samples per second.
Values:
-
enumerator AUDIO_HAL_08K_SAMPLES
set to 8k samples per second
-
enumerator AUDIO_HAL_11K_SAMPLES
set to 11.025k samples per second
-
enumerator AUDIO_HAL_16K_SAMPLES
set to 16k samples in per second
-
enumerator AUDIO_HAL_22K_SAMPLES
set to 22.050k samples per second
-
enumerator AUDIO_HAL_24K_SAMPLES
set to 24k samples in per second
-
enumerator AUDIO_HAL_32K_SAMPLES
set to 32k samples in per second
-
enumerator AUDIO_HAL_44K_SAMPLES
set to 44.1k samples per second
-
enumerator AUDIO_HAL_48K_SAMPLES
set to 48k samples per second
-
enumerator AUDIO_HAL_08K_SAMPLES