Audio Codec

Overview

The Audio Codec API provides access to digital audio codecs.

Configuration Options

Related configuration options:

API Reference

group audio_codec_interface

Abstraction for audio codecs.

Enums

enum audio_pcm_rate_t

PCM audio sample rates.

Values:

enumerator AUDIO_PCM_RATE_8K = 8000

8 kHz sample rate

enumerator AUDIO_PCM_RATE_16K = 16000

16 kHz sample rate

enumerator AUDIO_PCM_RATE_24K = 24000

24 kHz sample rate

enumerator AUDIO_PCM_RATE_32K = 32000

32 kHz sample rate

enumerator AUDIO_PCM_RATE_44P1K = 44100

44.1 kHz sample rate

enumerator AUDIO_PCM_RATE_48K = 48000

48 kHz sample rate

enumerator AUDIO_PCM_RATE_96K = 96000

96 kHz sample rate

enumerator AUDIO_PCM_RATE_192K = 192000

192 kHz sample rate

enum audio_pcm_width_t

PCM audio sample bit widths.

Values:

enumerator AUDIO_PCM_WIDTH_16_BITS = 16

16-bit sample width

enumerator AUDIO_PCM_WIDTH_20_BITS = 20

20-bit sample width

enumerator AUDIO_PCM_WIDTH_24_BITS = 24

24-bit sample width

enumerator AUDIO_PCM_WIDTH_32_BITS = 32

32-bit sample width

enum audio_dai_type_t

Digital Audio Interface (DAI) type.

Values:

enumerator AUDIO_DAI_TYPE_I2S

I2S Interface.

enumerator AUDIO_DAI_TYPE_INVALID

Other interfaces can be added here.

enum audio_property_t

Codec properties that can be set by audio_codec_set_property().

Values:

enumerator AUDIO_PROPERTY_OUTPUT_VOLUME

Output volume.

enumerator AUDIO_PROPERTY_OUTPUT_MUTE

Output mute/unmute.

enum audio_channel_t

Audio channel identifiers to use in audio_codec_set_property().

Values:

enumerator AUDIO_CHANNEL_FRONT_LEFT

Front left channel.

enumerator AUDIO_CHANNEL_FRONT_RIGHT

Front right channel.

enumerator AUDIO_CHANNEL_LFE

Low frequency effect channel.

enumerator AUDIO_CHANNEL_FRONT_CENTER

Front center channel.

enumerator AUDIO_CHANNEL_REAR_LEFT

Rear left channel.

enumerator AUDIO_CHANNEL_REAR_RIGHT

Rear right channel.

enumerator AUDIO_CHANNEL_REAR_CENTER

Rear center channel.

enumerator AUDIO_CHANNEL_SIDE_LEFT

Side left channel.

enumerator AUDIO_CHANNEL_SIDE_RIGHT

Side right channel.

enumerator AUDIO_CHANNEL_ALL

All channels.

Functions

static inline int audio_codec_configure(const struct device *dev, struct audio_codec_cfg *cfg)

Configure the audio codec.

Configure the audio codec device according to the configuration parameters provided as input

Parameters:

  • dev – Pointer to the device structure for codec driver instance.

  • cfg – Pointer to the structure containing the codec configuration.

Returns:

0 on success, negative error code on failure

static inline void audio_codec_start_output(const struct device *dev)

Set codec to start output audio playback.

Setup the audio codec device to start the audio playback

Parameters:

  • dev – Pointer to the device structure for codec driver instance.

static inline void audio_codec_stop_output(const struct device *dev)

Set codec to stop output audio playback.

Setup the audio codec device to stop the audio playback

Parameters:

  • dev – Pointer to the device structure for codec driver instance.

static inline int audio_codec_set_property(const struct device *dev, audio_property_t property, audio_channel_t channel, audio_property_value_t val)

Set a codec property defined by audio_property_t.

Set a property such as volume level, clock configuration etc.

Parameters:

  • dev – Pointer to the device structure for codec driver instance.

  • property – The codec property to set

  • channel – The audio channel for which the property has to be set

  • val – pointer to a property value of type audio_codec_property_value_t

Returns:

0 on success, negative error code on failure

static inline int audio_codec_apply_properties(const struct device *dev)

Atomically apply any cached properties.

Following one or more invocations of audio_codec_set_property, that may have been cached by the driver, audio_codec_apply_properties can be invoked to apply all the properties as atomic as possible

Parameters:

  • dev – Pointer to the device structure for codec driver instance.

Returns:

0 on success, negative error code on failure

union audio_dai_cfg_t
#include <codec.h>

Digital Audio Interface Configuration.

Configuration is dependent on DAI type

Public Members

struct i2s_config i2s

I2S configuration.

struct audio_codec_cfg
#include <codec.h>

Codec configuration parameters.

Public Members

uint32_t mclk_freq

MCLK input frequency in Hz.

audio_dai_type_t dai_type

Digital interface type.

audio_dai_cfg_t dai_cfg

DAI configuration info.

union audio_property_value_t
#include <codec.h>

Codec property values.

Public Members

int vol

Volume level in 0.5dB resolution.

bool mute

Mute if true, unmute if false.