AMR Decoder and Encoder

Decode and encode an audio data stream from / to AMR format. Encoders cover both AMR-NB and AMR-WB formats.

Application Examples

Implementation of this API is demonstrated in the following examples:

API Reference - Decoder

Header File

Functions

audio_element_handle_t amr_decoder_init(amr_decoder_cfg_t *config)

Create an Audio Element handle to decode incoming AMR data.

参数

config – The configuration

返回

The audio element handle

Structures

struct amr_decoder_cfg_t

AMR Decoder configuration.

Public Members

int out_rb_size

Size of output ringbuffer

int task_stack

Task stack size

int task_core

CPU core number (0 or 1) where decoder task in running

int task_prio

Task priority (based on freeRTOS priority)

bool stack_in_ext

Try to allocate stack in external memory

Macros

AMR_DECODER_TASK_STACK_SIZE
AMR_DECODER_TASK_CORE
AMR_DECODER_TASK_PRIO
AMR_DECODER_RINGBUFFER_SIZE
DEFAULT_AMR_DECODER_CONFIG()

API Reference - AMR-NB Encoder

Header File

Functions

esp_err_t amrnb_encoder_set_bitrate(audio_element_handle_t self, amrnb_encoder_bitrate_t bitrate_mode)

Set AMRNB encoder bitrate.

参数
  • self – Audio element handle

  • bitrate_mode – Bitrate choose, value from amrnb_encoder_bitrate_t

返回

ESP_OK ESP_FAIL

audio_element_handle_t amrnb_encoder_init(amrnb_encoder_cfg_t *config)

Create an Audio Element handle to encode incoming AMRNB data.

参数

config – The configuration

返回

The audio element handle

Structures

struct amrnb_encoder_cfg_t

AMRNB Encoder configurations.

Public Members

int out_rb_size

Size of output ringbuffer

int task_stack

Task stack size

int task_core

Task running in core (0 or 1)

int task_prio

Task priority (based on freeRTOS priority)

amrnb_encoder_bitrate_t bitrate_mode

AMRNB Encoder bitrate choose

bool contain_amrnb_header

Choose to contain amrnb header in amrnb encoder whether or not (true or false, true means choose to contain amrnb header)

bool stack_in_ext

Try to allocate stack in external memory

Macros

AMRNB_ENCODER_TASK_STACK
AMRNB_ENCODER_TASK_CORE
AMRNB_ENCODER_TASK_PRIO
AMRNB_ENCODER_RINGBUFFER_SIZE
DEFAULT_AMRNB_ENCODER_CONFIG()

Enumerations

enum amrnb_encoder_bitrate_t

Enum of AMRNB Encoder bitrate choose.

Values:

enumerator AMRNB_ENC_BITRATE_UNKNOW

Invalid mode

enumerator AMRNB_ENC_BITRATE_MR475
enumerator AMRNB_ENC_BITRATE_MR515
enumerator AMRNB_ENC_BITRATE_MR59
enumerator AMRNB_ENC_BITRATE_MR67
enumerator AMRNB_ENC_BITRATE_MR74
enumerator AMRNB_ENC_BITRATE_MR795
enumerator AMRNB_ENC_BITRATE_MR102
enumerator AMRNB_ENC_BITRATE_MR122
enumerator AMRNB_ENC_BITRATE_MRDTX
enumerator AMRNB_ENC_BITRATE_N_MODES

API Reference - AMR-WB Encoder

Header File

Functions

esp_err_t amrwb_encoder_set_bitrate(audio_element_handle_t self, amrwb_encoder_bitrate_t bitrate_mode)

Set AMRWB encoder bitrate.

参数
  • self – Audio element handle

  • bitrate_mode – Bitrate choose, value from amrwb_encoder_bitrate_t

返回

ESP_OK ESP_FAIL

audio_element_handle_t amrwb_encoder_init(amrwb_encoder_cfg_t *config)

Create an Audio Element handle to encode incoming amrwb data.

参数

config – The configuration

返回

The audio element handle

Structures

struct amrwb_encoder_cfg_t

AMRWB Encoder configurations.

Public Members

int out_rb_size

Size of output ringbuffer

int task_stack

Task stack size

int task_core

Task running in core (0 or 1)

int task_prio

Task priority (based on freeRTOS priority)

amrwb_encoder_bitrate_t bitrate_mode

AMRWB Encoder bitrate choose

bool contain_amrwb_header

Choose to contain amrwb header in amrwb encoder whether or not (true or false, true means choose to contain amrwb header)

bool stack_in_ext

Try to allocate stack in external memory

Macros

AMRWB_ENCODER_TASK_STACK
AMRWB_ENCODER_TASK_CORE
AMRWB_ENCODER_TASK_PRIO
AMRWB_ENCODER_RINGBUFFER_SIZE
DEFAULT_AMRWB_ENCODER_CONFIG()

Enumerations

enum amrwb_encoder_bitrate_t

Enum of AMRWB Encoder bitrate choose.

Values:

enumerator AMRWB_ENC_BITRATE_MDNONE

Invalid mode

enumerator AMRWB_ENC_BITRATE_MD66

6.60kbps

enumerator AMRWB_ENC_BITRATE_MD885

8.85kbps

enumerator AMRWB_ENC_BITRATE_MD1265

12.65kbps

enumerator AMRWB_ENC_BITRATE_MD1425

14.25kbps

enumerator AMRWB_ENC_BITRATE_MD1585

15.85bps

enumerator AMRWB_ENC_BITRATE_MD1825

18.25bps

enumerator AMRWB_ENC_BITRATE_MD1985

19.85kbps

enumerator AMRWB_ENC_BITRATE_MD2305

23.05kbps

enumerator AMRWB_ENC_BITRATE_MD2385

23.85kbps>

enumerator AMRWB_ENC_BITRATE_N_MODES

Invalid mode