基于LM的（GB28181/EHOME）设备语音指挥（对讲、广播）
简介
LM视频中间音频对讲和广播，支持一对一、一对多、多对多、控制前端播放自定wav语音文件及创建语音聊天室等功能，可基于基础安防设备实现实时多方语音通话、语音喊话及报警联动语音播放等场景下语音交互。
LM视频中间件支持的设备如下：
- 全系列海康设备
- 全系列大华设备
- GB28181设备（内网UDP/TCP，外网TCP模式）
- EHOME协议设备，包含ISUP
- LM主要对外开放接口有，开启对讲（广播）、关闭对讲（广播）、发送语音和发送wav文件播放等，详细API说明见API说明文档
提示
需设备上安装了麦克风和喇叭
API接口说明
开启对讲(广播)
此接口为开启或加入对讲(组)，其中请求参数
- deviceId 可以为空时，为用户发起新建（加入）对讲组，本次请求不添加新的设备到对讲组中
- ssid为0时，代表新建对讲（广播）组，当ssid不为0时为加入已存在的对讲组，ssid对讲组必须要存在，否则会返回对讲组不存在的错误
注：
- 用户创建对讲组后，若在一段时间内（15秒）不调用发送语音或者播放wav文件接口，LM将自动释放当前对讲组，同时关闭和前端设备之间的对讲会话。
- 如对讲的设备已被对讲组占用，LM会在接口返回User Already Opening错误，调用者可以在接口返回的数组详情中得到占用设备得对讲组ssid，从而再发起加入对讲组得请求进行语音通讯。
请求
POST /api/v1/talk/start?token=f384932b-92b9-4947-a567-10c33a82b44f HTTP/1.1
Content-Type: application/json
Accept: */*
Accept-Encoding: gzip, deflate, br
Connection: keep-alive
Content-Length: 63
{
"ssid":0,
"deviceId":[
"A20221214135512",
"A123445"
]
}
应答
返回的信息需要到detail数组中获取每个设备的开启结果
HTTP/1.1 200 OK
Content-Type: application/json
Content-Length: 177
Connection: keep-alive
Access-Control-Allow-Origin: *
{
"result": 200,
"message": "OK",
"ssid": 1,
"detail": [
{
"deviceId": "A20221214135512",
"result": "OK"
},
{
"deviceId": "A123445",
"result": "Invalid Device ID"
}
]
}
关闭对讲（广播）
此接口为关闭对讲组接口,使用时也可以不调用此接口，LM也会自动检测是否还存在用户存在对讲组中，接口参数
- deviceId为空时关闭参数ssid指定的对讲组
- ssId为非0且LM中必须存在此对讲组
请求
POST /api/v1/talk/stop?token=8305918c-69e8-4280-ae22-85aa5d696e0e HTTP/1.1
Content-Type: application/json
Accept: */*
Host: 192.168.3.23:9030
Accept-Encoding: gzip, deflate, br
Connection: keep-alive
Content-Length: 20
{
"ssid":636
}
!!! sample “应答”
HTTP/1.1 200 OK
Content-Type: application/json
Content-Length: 42
Connection: keep-alive
Access-Control-Allow-Origin: *
{
"result": 200,
"message": "OK"
}
发送语音
此接口是在打开对讲接口调用成功后返回后，客户端使用websocket发送本地及采集的PCM语音数据，语音采样率：44000， 采样位为16， 单通道。
播放wav文件
本接口仅支持WAV格式的PCM语音文件
网页H5音频采集
网页音频采用使用的是HTML5的getUserMedia API，getUserMedia API为用户提供访问硬件设备媒体（摄像头、视频、音频、地理位置等）的接口，基于该接口，开发者可以在不依赖任何浏览器插件的条件下访问硬件媒体设备。getUserMedia API的浏览器兼容行如图示：
注意
需要网页H5支持采集音频有以下两种方式（以Chrome浏览器为例子）：
- 服务器端开启https
- 浏览本地设置例外，进入浏览器本地设置
- 地址栏输入chrome://flags/
- 在设置页面找到选项Insecure origins treated as secure，添加例外服务器地址，重启浏览器即可在开发环境采集音频
采集音频
initTalk(){// 初始化多媒体对象
if (!navigator.mediaDevices.getUserMedia) {
alert('浏览器不支持音频输入');
} else if(this.record == null){
navigator.mediaDevices.getUserMedia = navigator.mediaDevices.getUserMedia || navigator.mediaDevices.webkitGetUserMedia;
navigator.mediaDevices.getUserMedia({audio: true})
.then((mediaStream)=> {
this.record = new this.getRecorder(mediaStream)
})
}
}
getRecorder(stream){
let sampleBits = 16;//输出采样数位 8, 16
let sampleRate = 44100;//输出采样率
let bufSize = 8192;
let context = new AudioContext();
let audioInput = context.createMediaStreamSource(stream);
let recorder = context.createScriptProcessor(0, 1, 1);
let audio_resample = new Resampler(context.sampleRate, sampleRate, 1, bufSize);
console.log(audio_resample);
let audioData = {
size: 0, //录音文件长度
buffer: [], //录音缓存
inputSampleRate: sampleRate, //输入采样率
inputSampleBits: 16, //输入采样数位 8, 16
outputSampleRate: sampleRate,
oututSampleBits: sampleBits,
clear: function () {
audioData.buffer = [];
audioData.size = 0;
},
input: function (data) {
audioData.buffer.push(new Float32Array(data));
audioData.size += data.length;
},
compress: function () { //合并压缩
//合并
let data = new Float32Array(this.size);
let offset = 0;
for (let i = 0; i < this.buffer.length; i++) {
data.set(this.buffer[i], offset);
offset += this.buffer[i].length;
}
//压缩
let compression = parseInt(this.inputSampleRate / this.outputSampleRate);
let length = data.length / compression;
let result = new Float32Array(length);
let index = 0, j = 0;
while (index < length) {
result[index] = data[j];
j += compression;
index++;
}
return result;
},
encodePCM: function () {//这里不对采集到的数据进行其他格式处理，如有需要均交给服务器端处理。
let sampleRate = Math.min(this.inputSampleRate, this.outputSampleRate);
let sampleBits = Math.min(this.inputSampleBits, this.oututSampleBits);
let bytes = this.compress();
let dataLength = bytes.length * (sampleBits / 8);
let buffer = new ArrayBuffer(dataLength);
let data = new DataView(buffer);
let offset = 0;
for (let i = 0; i < bytes.length; i++, offset += 2) {
let s = Math.max(-1, Math.min(1, bytes[i]));
data.setInt16(offset, s < 0 ? s * 0x8000 : s * 0x7FFF, true);
}
return new Blob([data]);
}
};
this.start = function () {
audioInput.connect(recorder);
recorder.connect(context.destination);
}
this.stop = function () {
recorder.disconnect();
}
this.getBlob = function () {
return audioData.encodePCM();
}
this.clear = function () {
audioData.clear();
}
recorder.onaudioprocess = function (e) {
//audioData.input(e.inputBuffer.getChannelData(0));
audioData.input(audio_resample.resample(e.inputBuffer.getChannelData(0)));
}
}
getTalkStart(){
this.initTalk()
if(this.talkOpen){ // this.talkOpen为true开启对讲
let data = {
deviceId: [this.orgId],
ssid: 0
};
talkStartServe(data,this.getToken()).then(res => {
if(res.result==200 && res.ssid != 0) {
this.ssid = res.ssid
this.imgSrc = require('@/assets/img/yj-open.png')
this.$message.success('设备对讲已开启')
this.talkOpen = false
this.sendTalk()
}else {
if(res.detail[0] != undefined){
if(res.detail[0].result == "User Opened Talking"){
this.ssid = res.detail[0].ssid
this.imgSrc = require('@/assets/img/yj-open.png')
this.$message.success('设备对讲已开启')
this.talkOpen = false
this.sendTalk()
}
else{
this.$message.error(res.detail[0].result)
this.imgSrc = require('@/assets/img/yunjing.png')
this.talkOpen = true
}
}
else{
this.$message.error("对讲打开失败");
this.imgSrc = require('@/assets/img/yunjing.png')
this.talkOpen = true
}
}
})
}else { // 关闭对讲
if(this.record != null){
this.record.stop();
}
if(this.socket != null){
this.socket.close();
}
if(this.pcmPlayer != null){
this.pcmPlayer.destroy();
this.pcmPlayer = null;
}
//不需要关闭，后台会根据连接自动关闭对讲组
this.$message.success('设备对讲已关闭')
this.imgSrc = require('@/assets/img/yunjing.png')
this.talkOpen = true
/*talkStopServe({ssid: this.ssid},this.getToken()).then(res => {
if(res.result==200) {
this.$message.success('设备对讲已关闭')
this.imgSrc = require('@/assets/img/yunjing.png')
this.talkOpen = true
}else {
this.$message.error('操作失败')
this.imgSrc = require('@/assets/img/yj-open.png')
this.talkOpen = false
}
})*/
}
}
发送音频
sendTalk() {// WebSocket发送音频
let that = this // this指向会有问题that代替
let locUrl = window.location.host
let stemp = '';
if(window.location.protocol === 'https:')
{
stemp ='s';
}
const socketUrl = 'ws' + stemp +'://'+ locUrl + '/ws_talk/'+this.ssid+'?token='+this.getToken();// + '&sampleRate=' + this.context.sampleRate;
that.socket = new WebSocket(socketUrl)
that.socket.binaryType = 'arraybuffer'
that.socket.onopen = function () {
console.log('浏览器WebSocket已打开');
if(that.record != null){
that.record.start();
}
else
{
console.log('声音采集打开失败');
}
window.timeInte = setInterval(() => {
if(that.socket != null && that.socket.readyState == 1) {
if (that.record != null && that.record.getBlob().size != 0) {
that.socket.send(that.record.getBlob()); //发送音频数据
that.record.clear();
}
}
},20)
};
if(that.pcmPlayer == null)
{
that.pcmPlayer = new PCMPlayer({
inputCodec: 'Int16',
channels: 1,
sampleRate: 16000,
flushTime: 200
})
}
that.socket.onmessage = function(msg) {// 接收WebSocket消息
that.pcmPlayer.feed(msg.data)
}
}
常见错误码
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