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X2000 Webrtc回声消除调试pc环境

一 概述​

该测试环境硬件需要amic回采电路，通过amic硬件回采以及dmic录⾳进⾏消回声(aec)，当开发板与PC连接时，可以在PC上通过应用工具（普通播放器、音频处理软件等）控制开发板的icodec播放、dmic录音及amic回采，并且能够实时地观察到基于回声消除算法库（Webrtc）处理后的回声消除效果.

二 配置​

2.1 回声消除相关demo​

代码文件位置libmedia/test/main_webrtc_uac_aec_cc_test.c

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2.2 播放、录⾳与回读功能​

声卡驱动配置

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amic作为硬件回采

  • 关闭偏置电压
  • 偏置电压寄存器设置为0
  • MICL模拟增益设置为0
  • ALCL模拟增益推荐14

dmic作为录音设备

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创建声卡设备

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2.3 buildroot配置​

bhu@bhu-PC:~/work/buildroot/buildroot24$ make menuconfig

编译webrtc库需要工具链gcc1210

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2.4 kernel uac 配置​

bhu@bhu-PC:~/work/kernel/kernel$ make menuconfig

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2.5 uac2.0设备配置脚本​

uac2_device_config.sh位于目录doc/开发使用说明/第三方库使用说明/硬件回环回声消除测试环境

#!/bin/bash

VID="0x18d1"
PID="0xd002"

function start_uac2()
{
	echo "Creating the USB gadget..."
	mount -t configfs none /sys/kernel/config

	mkdir -m 0770 /sys/kernel/config/usb_gadget/g1

	# 设置产品的VendorID、ProductID及USB规范版本号
	echo "Setting Device Descriptor..."
	echo 0x00 > /sys/kernel/config/usb_gadget/g1/bDeviceClass
	echo 0x00 > /sys/kernel/config/usb_gadget/g1/bDeviceSubClass
	echo 0x00 > /sys/kernel/config/usb_gadget/g1/bDeviceProtocol
	echo 0x0200 > /sys/kernel/config/usb_gadget/g1/bcdUSB
	echo 0x0200 > /sys/kernel/config/usb_gadget/g1/bcdDevice
	echo $VID > /sys/kernel/config/usb_gadget/g1/idVendor
	echo $PID > /sys/kernel/config/usb_gadget/g1/idProduct

	# 实例化英语ID，开发商、产品和序列号字符串写入内核
	echo "Setting English strings..."
	mkdir -m 0770 /sys/kernel/config/usb_gadget/g1/strings/0x409
	echo "ingenic"  > /sys/kernel/config/usb_gadget/g1/strings/0x409/manufacturer
	echo "audio"  > /sys/kernel/config/usb_gadget/g1/strings/0x409/product
	echo "your_serial_num" > /sys/kernel/config/usb_gadget/g1/strings/0x409/serialnumber

	# Creating Config
	echo "Creating Config..."
	mkdir -m 0770 /sys/kernel/config/usb_gadget/g1/configs/c.1
	mkdir -m 0770 /sys/kernel/config/usb_gadget/g1/configs/c.1/strings/0x409
	echo "uac2" > /sys/kernel/config/usb_gadget/g1/configs/c.1/strings/0x409/configuration
	echo 500 > /sys/kernel/config/usb_gadget/g1/configs/c.1/MaxPower
	echo 0x80 > /sys/kernel/config/usb_gadget/g1/configs/c.1/bmAttributes

	 
	# Creating functions
	echo "Creating functions..."
	mkdir /sys/kernel/config/usb_gadget/g1/functions/uac2.0
	echo "0x01" > /sys/kernel/config/usb_gadget/g1/functions/uac2.0/c_chmask
	echo "2" > /sys/kernel/config/usb_gadget/g1/functions/uac2.0/c_ssize
	echo $SAMPLE_RATE > /sys/kernel/config/usb_gadget/g1/functions/uac2.0/c_srate
	echo "0x07" > /sys/kernel/config/usb_gadget/g1/functions/uac2.0/p_chmask
	echo "2" > /sys/kernel/config/usb_gadget/g1/functions/uac2.0/p_ssize
	echo $SAMPLE_RATE > /sys/kernel/config/usb_gadget/g1/functions/uac2.0/p_srate
	echo "2" > /sys/kernel/config/usb_gadget/g1/functions/uac2.0/req_number
	echo "adaptive" > /sys/kernel/config/usb_gadget/g1/functions/uac2.0/c_sync

	# Binding USB Device Controller
	echo "Binding USB Device Controller"
	ln -s /sys/kernel/config/usb_gadget/g1/functions/uac2.0 /sys/kernel/config/usb_gadget/g1/configs/c.1
	echo 13500000.otg > /sys/kernel/config/usb_gadget/g1/UDC
}

function stop_uac2()
{
	# Disabling the gadget
	echo "Disabling the USB gadget"
	echo "" > /sys/kernel/config/usb_gadget/g1/UDC

	# Remove functions from configurations
	rm /sys/kernel/config/usb_gadget/g1/configs/c.1/uac2.0
	# Remove strings directories in configurations
	rmdir /sys/kernel/config/usb_gadget/g1/configs/c.1/strings/0x409
	# remove the configurations
	rmdir /sys/kernel/config/usb_gadget/g1/configs/c.1
	# Remove functions (function modules are not unloaded, though)
	rmdir /sys/kernel/config/usb_gadget/g1/functions/uac2.0
	# Remove strings directories in the gadget
	rmdir /sys/kernel/config/usb_gadget/g1/strings/0x409
	# finally remove the gadget
	rmdir /sys/kernel/config/usb_gadget/g1

	umount /sys/kernel/config
}

usage()
{
    echo "Usage: ./usb-gadget-uac2.sh start|stop"
    echo " options:"
    echo "   start [sample_rate]   uac2.0 gadget, setting rate of both capture and playback"
    echo "   stop                  uac2.0 gadget"
}

case $1 in
start)
    if [ "$#" -lt 2 ]; then
        usage
        exit 1
    fi

    SAMPLE_RATE=$2
	start_uac2
	;;
stop)
	stop_uac2
	;;
*)
	usage
	exit 1
	;;
esac
exit 0


三 验证​

3.1 模拟uac设备​

在终端运行uac设备脚本

sh uac2_device_config.sh start 48000               //48000为采样率

3.2 修改回声消除测试demo​

代码文件位置libmedia/test/main_webrtc_uac_aec_cc_test.c

# arecord -l
**** List of CAPTURE Hardware Devices ****
card 0: dmicsoundcard [dmic-sound-card], device 0: x2000 DMIC snd-soc-dummy-dai-0 []
  Subdevices: 1/1
  Subdevice #0: subdevice #0
card 1: icodecsoundcard [icodec-sound-card], device 0: x2000 icodec pcm ingenic-icodec-0 []
  Subdevices: 1/1
  Subdevice #0: subdevice #0
card 2: UAC2Gadget [UAC2_Gadget], device 0: UAC2 PCM [UAC2 PCM]
  Subdevices: 1/1
  Subdevice #0: subdevice #0
# aplay -l
**** List of PLAYBACK Hardware Devices ****
card 1: icodecsoundcard [icodec-sound-card], device 0: x2000 icodec pcm ingenic-icodec-0 []
  Subdevices: 1/1
  Subdevice #0: subdevice #0
card 2: UAC2Gadget [UAC2_Gadget], device 0: UAC2 PCM [UAC2 PCM]
  Subdevices: 1/1
  Subdevice #0: subdevice #0

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修改完后重新编译测试demo

3.3 运行测试demo​

webrtc_uac_aec_cc_test 48000        //48000为采样率

此处的采样率与uac设备配置脚本的采样率需要保持一致，变更时需要同时变更

3.4 pc端调试​

Audacity配置

运行应用Audacity，选择录制设备为模拟UAC设备，录制声道数为3，采样率相应设置为48000Hz

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设置完开始录制，打开任意音频文件选择该模拟UAC设备播放，测试回声消除效果

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由上到下，

第一行为回声消除后的音频数据，

第二行为实际录制到的音频数据，

第三行为回采到的音频数据（即模拟UAC设备播放的音频文件）