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

components/esp-adf-libs/esp_codec/include/codec/amr_decoder.h

Functions

audio_element_handle_t amr_decoder_init(amr_decoder_cfg_t *config)

Create an Audio Element handle to decode incoming AMR data.

Parameters: config – The configuration
Returns: 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

components/esp-adf-libs/esp_codec/include/codec/amrnb_encoder.h

Functions

esp_err_t amrnb_encoder_set_bitrate(audio_element_handle_t self, amrnb_encoder_bitrate_t bitrate_mode)

Set AMRNB encoder bitrate.

Parameters

self – Audio element handle
bitrate_mode – Bitrate choose, value from amrnb_encoder_bitrate_t

Returns

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.

Parameters: config – The configuration
Returns: 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

components/esp-adf-libs/esp_codec/include/codec/amrwb_encoder.h

Functions

esp_err_t amrwb_encoder_set_bitrate(audio_element_handle_t self, amrwb_encoder_bitrate_t bitrate_mode)

Set AMRWB encoder bitrate.

Parameters

self – Audio element handle
bitrate_mode – Bitrate choose, value from amrwb_encoder_bitrate_t

Returns

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.

Parameters: config – The configuration
Returns: 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

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