突发奇想小程序尝试着集成语音识别功能，对号入座般首选方案为百度语音识别nodejs REST API。

其流程如图所示：

小程序端录制语音代码 如下所示：

autoplay="{{autoplay}}" interval="{{interval}}" duration="{{duration}}">

{{audioState}}

//index.js

//录制音频参数

const options = {

duration: 60000,

sampleRate: 44100,

numberOfChannels: 1,

encodeBitRate: 192000,

format: 'mp3',

frameSize: 50

};

//语音录制管理器

const recorderManager = wx.getRecorderManager();

/**

* 开始录制语音

*

*/

startRecordAudio:function()

{

recorderManager.onStart(() => {

this.setData({ audioState: "语音录制中.." });

});

recorderManager.onResume(() => {

console.log('recorder resume')

});

recorderManager.onPause(() => {

this.setData({ audioState: "语音暂停录制" });

});

recorderManager.onStop((res) => {

console.log('recorder stop', res);

if (res.duration < 1000) {

this.setData({ audioState: "开始录制" });

wx.showToast({

title: '录音不能小于1秒钟',

});

return;

};

var that = this;

wx.saveFile({

tempFilePath: res.tempFilePath,

success: function (res) {

var savedFilePath = res.savedFilePath;

that.setData({ tempAudioFilePath: savedFilePath });

that.uploadRecordAudio();

}

})

});

recorderManager.onFrameRecorded((res) => {

const { frameBuffer } = res

console.log('frameBuffer.byteLength', frameBuffer.byteLength)

});

recorderManager.onError((res) => {

const { error } = res;

console.log("record error is " + error);

});

recorderManager.start(options);

},

/**

* 结束录制语音

*

*/

stopRecordAudio: function () {

this.setData({ audioState: "语音录制完成,上传中.." });

recorderManager.stop();

},

/**

* 上传录制语音

*

*/

uploadRecordAudio: function () {

wx.showLoading({

title: '音频上传中..',

})

this.setData({ audioState: this.data.tempAudioFilePath });

var that = this;

const uploadTask = wx.uploadFile({

url: 'http://10.129.83.13:3000/aip',

// url: 'http://aip.butterfly.mopaasapp.com/aip',

filePath: that.data.tempAudioFilePath,

name: 'file',

header: {

'content-type': 'multipart/form-data'

},

formData: {

'user': 'test'

},

success: function (res) {

//do something

console.log("res" + JSON.stringify(res));

wx.hideLoading();

that.echoRecordAudioContent(res.data);

}

});

uploadTask.onProgressUpdate((res) => {

this.setData({ audioState: "语音录制完成,上传中" + res.progress+".." });

console.log('上传进度', res.progress)

console.log('已经上传的数据长度', res.totalBytesSent)

console.log('预期需要上传的数据总长度', res.totalBytesExpectedToSend)

});

// uploadTask.abort() // 取消上传任务

},

/**

* 回显录制语音转化成的文字

*

*/

echoRecordAudioContent: function (obj) {

console.log("文字回显" + JSON.stringify(obj));

var title = obj.result[0];

wx.showToast({

title: obj.result,

})

}

后端代码实现采用的Nodejs+express解决方案(因为涉及到音频格式的转码 需要在本地部署ffmpeg进行音频格式的转化)

aip.js代码如下

var express = require('express');

var router = express.Router();

var fs = require('fs');

var formidable = require("formidable");

var ffmpeg = require('fluent-ffmpeg');

var AipSpeechClient = require("baidu-aip-sdk").speech;

// 设置APPID/AK/SK

var APP_ID = "******************";

var API_KEY = "******************";

var SECRET_KEY = "******************";

// 新建一个对象，建议只保存一个对象调用服务接口

var client = new AipSpeechClient(APP_ID, API_KEY, SECRET_KEY);

router.post('/', function(req, res, next) {

var tmp_path = null;

var target_path = null;

var form = new formidable.IncomingForm();

form.uploadDir = './uploads/tmp/';

form.maxFieldsSize = 20 * 1024 * 1024;

form.timeout =

form.parse(req,function(error,fields,files){

if(!error)

{

tmp_path = files.file.path;

// 指定文件上传后的目录 - 示例为"audio"目录。

target_path = './uploads/audio/' + files.file.name;

}

else

{

res.status(200).send("{'err_msg':'语音上传失败'}");

}

});

form.on('error', function(error) {

console.log('********************error'+error);

});

form.on('aborted', function() {

});

form.on('end', function() {

if(fs.existsSync(tmp_path))

{

// 移动文件

fs.rename(tmp_path, target_path, function(rename_err) {

if (rename_err) throw rename_err;

//使用ffmpeg 进行音频转换

convertAudioType(target_path).then((data) => {

if(data != undefined)

{

res.send(data);

}

else

{

res.status(200).send("{'err_msg':'语音上传失败'}");

}

});

});

}

});

});

//使用ffmpeg 进行音频转换 已经知道上传格式为aac

function convertAudioType(path)

{

return new Promise((resolve,reject) => {

//文件名称

var filename = path.substr(path.lastIndexOf('/')+1);

filename = filename.slice(0,filename.lastIndexOf('.'));

//输出文件路径

var outputPath = './assets/convert/audio/'+filename+'.wav';

const extractAudio = require('ffmpeg-extract-audio');

extractAudio({

input: path,

output: outputPath,

format:'wav',

transform: (cmd) => {

cmd.audioFilters([

{

filter: 'volume',

options: '0.5'

}

]);

cmd.on('error', function(err) {

if(err) return reject({"err_msg":"语音格式转换失败"});

});

cmd.on('end', function() {

var obj = convertToText(path).then((data) => {

console.log("******************"+JSON.stringify(data));

return JSON.stringify(data);

}).catch((error) => {

});

return resolve(obj);

});

}

});

});

}

//使用百度语音识别

function convertToText(path)

{

return new Promise((resolve,reject) => {

// setTimeout(function(){return resolve({"err_msg":"语音识别失败"});},1000);

var voice = fs.readFileSync(path);

var voiceBuffer = new Buffer(voice);

// 识别本地文件

client.recognize(voiceBuffer, 'wav', 16000).then(function (result) {

var data = result;

if(data.err_no == 0)

{

//{"corpus_no":"6543498202833665207","err_msg":"success.","err_no":0,"result":["欢迎使用百度语音合成，"],"sn":"321835246031523526898"}

return resolve({"err_msg":"success","result":data.result[0]}); //小程序端直接cancel了请求

}

else

{

//{"err_msg":"speech quality error.","err_no":3301,"sn":"725439393781523526861"}

return resolve({"err_msg":"语音识别失败"}); //小程序端可以接收到 response

}

}, function(err)

{

console.log(err);

if(err) return reject({"err_msg":"语音识别失败"});

});

});

}

module.exports = router;

问题来了，红色标注如下图：

问题在持续跟踪中，也给百度反馈了，等待百度给出合理的解释。。。