AEC

[中文]

1 Functional Overview

The main function of the echo cancellation library is to eliminate the echo in the voice call scene to ensure high-quality voice calls, and it also has the functions of noise reduction and volume adjustment.

2 Code Path

demo path: \components\demos\media\audio\aec

For the detailed description of the API interface of the AEC library, please refer to the same webpage: /api-reference/multi_media/bk_aec.html

3 Cli command introduction

The commands supported by the demo are as follows:

Command	Description
aec_test	run AEC demo

The macro configuration that the demo runs depends on:

Name	Description	File	value
CONFIG_AUDIO_AEC	Configure whether AEC is compiled as a library	\properties\soc\bk7256\bk7256.defconfig	y
CONFIG_AUDIO_TEST	Whether the configuration demo takes effect	\middleware\soc\bk7256\bk7256.defconfig	y

Demo runs dependent libraries and drivers:

• libaec.a AEC echo cancellation library

• SD SDcard and file system driver

4 Demo introduction

The steps performed by the demo are as follows:

1.Prepare the audio files needed for the test

• Save the original mic audio file mic.pcm and the corresponding reference signal ref.pcm file that needs echo cancellation and noise reduction provided in the demo path in the root directory of the TF card

2.Mount TF card

• Uart sends AT command fatfstest M 1 to mount TF card

3.execute the test

• Uart sends the AT command aec_test to execute the test and output the audio file after echo cancellation out.pcm

Execute the test command, the workflow of the case is shown in the following figure:

Figure 1. aec demo flow chart

5 Detailed configuration and description

Important

Precautions:

• 1.The AEC algorithm requires more than 20 kBytes of buffers, and the memory of AECContext needs to be allocated before initialization;

• 2.Algorithm parameters are adjusted using the aec_ctrl interface.