Audio Driver Configuration

[ [English] | 简体中文 ]

I. Opening the Configuration Interface

1. Open menuconfig.

2. Search for the keyword audio.

3. Locate the Audio Support configuration item. The interface is shown in the figure below (UI color scheme may vary).

   

II. Explanation of Configuration Items

Audio Support

• Function: Enable audio device driver.

  • Required for all product categories except specific module types.

Support Audio Composition

• Function: Support composite nodes.

  • Detailed explanation of composite nodes can be found in Audio Driver Principle Description.

Support Multiple Sessions

• Function: Support multiple sessions.

  • By default, this option is usually disabled.

Audio Buffer Configuration

• Function: Configure audio buffer.

  • Buffers are used for data transfer between applications and the audio driver.

Support Audio Buffers with Greater Than 65K Samples

• Function: Support buffers larger than 65K samples.

  • By default, buffer size is defined using uint16_t, with a maximum of 32K samples. After enabling this option, buffer size is defined using uint32_t, supporting up to 65K samples.

  • Code example:

    #ifdef CONFIG_AUDIO_LARGE_BUFFERS
    typedef uint32_t apb_samp_t;
    #else
    typedef uint16_t apb_samp_t;
    #endif
    

Number of Buffers for Audio Processing

• Function: Set the number of buffers for audio processing.

  • Default value: 2.

Size of Each Audio Buffer for Audio Processing

• Function: Set the size of each audio processing buffer.

  • Default value: 8192.

Support for Driver-Specified Buffer Sizes

• Function: Support custom buffer sizes and quantities.

Supported Audio Formats

• Function: Configure audio formats supported by the device.

  • Supported formats include:

    • PCM Audio: Support for PCM format.
    • MPEG 3 Layer 1: Support for audio compression devices; other formats can be selected based on device capabilities.

Exclude Specific Audio Features

• Function: Exclude specific audio features.

Use Custom Device Path

• Function: Customize the registration path of audio device nodes.

  • Default registration path: /dev/audio.

III. Configuration Examples

Two typical audio configuration examples are provided below: Simulator Environment and a certain hardware platform. Users can refer to these configurations based on actual needs.

1. Simulator Environment

The following is an audio configuration example for the Simulator Environment:

#
# Audio Support
#
CONFIG_AUDIO=y
# CONFIG_AUDIO_COMP is not set
# CONFIG_AUDIO_MULTI_SESSION is not set

#
# Audio Buffer Configuration
#
# CONFIG_AUDIO_LARGE_BUFFERS is not set
CONFIG_AUDIO_NUM_BUFFERS=2
CONFIG_AUDIO_BUFFER_NUMBYTES=8192
# CONFIG_AUDIO_DRIVER_SPECIFIC_BUFFERS is not set

#
# Supported Audio Formats
#
# CONFIG_AUDIO_FORMAT_AC3 is not set
# CONFIG_AUDIO_FORMAT_DTS is not set
CONFIG_AUDIO_FORMAT_PCM=y
# CONFIG_AUDIO_FORMAT_RAW is not set
CONFIG_AUDIO_FORMAT_MP3=y
# CONFIG_AUDIO_FORMAT_MIDI is not set
# CONFIG_AUDIO_FORMAT_WMA is not set
# CONFIG_AUDIO_FORMAT_OGG_VORBIS is not set

#
# Exclude Specific Audio Features
#
# CONFIG_AUDIO_EXCLUDE_VOLUME is not set
# CONFIG_AUDIO_EXCLUDE_BALANCE is not set
CONFIG_AUDIO_EXCLUDE_EQUALIZER=y
# CONFIG_AUDIO_EXCLUDE_TONE is not set
# CONFIG_AUDIO_EXCLUDE_PAUSE_RESUME is not set
# CONFIG_AUDIO_EXCLUDE_STOP is not set
# CONFIG_AUDIO_EXCLUDE_FFORWARD is not set
CONFIG_AUDIO_EXCLUDE_REWIND=y
# CONFIG_AUDIO_CUSTOM_DEV_PATH is not set

2. Certain Hardware Platform

The following is an audio configuration example for a certain hardware platform:

#
# Audio Support
#
CONFIG_AUDIO=y
# CONFIG_AUDIO_COMP is not set
# CONFIG_AUDIO_MULTI_SESSION is not set

#
# Audio Buffer Configuration
#
# CONFIG_AUDIO_LARGE_BUFFERS is not set
CONFIG_AUDIO_NUM_BUFFERS=2
CONFIG_AUDIO_BUFFER_NUMBYTES=8192
CONFIG_AUDIO_DRIVER_SPECIFIC_BUFFERS=y

#
# Supported Audio Formats
#
# CONFIG_AUDIO_FORMAT_AC3 is not set
# CONFIG_AUDIO_FORMAT_DTS is not set
CONFIG_AUDIO_FORMAT_PCM=y
# CONFIG_AUDIO_FORMAT_RAW is not set
# CONFIG_AUDIO_FORMAT_MP3 is not set
# CONFIG_AUDIO_FORMAT_MIDI is not set
# CONFIG_AUDIO_FORMAT_WMA is not set
# CONFIG_AUDIO_FORMAT_OGG_VORBIS is not set

#
# Exclude Specific Audio Features
#
# CONFIG_AUDIO_EXCLUDE_VOLUME is not set
# CONFIG_AUDIO_EXCLUDE_BALANCE is not set
CONFIG_AUDIO_EXCLUDE_EQUALIZER=y
# CONFIG_AUDIO_EXCLUDE_TONE is not set
# CONFIG_AUDIO_EXCLUDE_PAUSE_RESUME is not set
# CONFIG_AUDIO_EXCLUDE_STOP is not set
# CONFIG_AUDIO_EXCLUDE_FFORWARD is not set
CONFIG_AUDIO_EXCLUDE_REWIND=y
# CONFIG_AUDIO_CUSTOM_DEV_PATH is not set