百度语音测试并导出到Android平台

参考链接：https://www.jianshu.com/p/813b4209458d
新建按钮控件（改名为btnRecorder），自动生成canvas和eventsystem，然后canvas下加入text文本控件（不改名）。canvas不用设置，按钮控件挂载代码BaiduASR.cs，其他设置如下：

文本控件大小设置如下：

切换到安卓平台，如下：

player setting如下（包名和.net以及target API版本的设置）：

然后导出项目即可。

BaiduASR.cs代码如下：

using System;
using System.Collections;
using System.Text.RegularExpressions;
using UnityEngine;
using UnityEngine.EventSystems;
using UnityEngine.Networking;
using UnityEngine.UI;

//RequireComponent的这两个组件主要用于播放自己录制的声音,不需要刻意删除,同时注意删除使用组件的代码
[RequireComponent(typeof(AudioListener)), RequireComponent(typeof(AudioSource))]
public class BaiduASR : MonoBehaviour, IPointerDownHandler, IPointerUpHandler
{
//百度语音识别相关key
//string appId = “”;
string apiKey = “bn58jNgdjRED0uKCScW9R2C6”; //填写自己的apiKey
string secretKey = “LgLYImS2Hcxqno6QQzIMrH7Gf8uRRbZb”; //填写自己的secretKey

//记录accesstoken令牌
string accessToken = string.Empty;

//语音识别的结果
string asrResult = string.Empty;

//标记是否有麦克风
private bool isHaveMic = false;

//当前录音设备名称
string currentDeviceName = string.Empty;

//录音频率,控制录音质量(8000,16000)
int recordFrequency = 8000;

//上次按下时间戳
double lastPressTimestamp = 0;

//表示录音的最大时长
int recordMaxLength = 10;

//实际录音长度(由于unity的录音需先指定长度,导致识别上传时候会上传多余的无效字节)
//通过该字段,获取有效录音长度,上传时候剪切到无效的字节数据即可
int trueLength = 0;

//存储录音的片段
[HideInInspector]
public AudioClip saveAudioClip;

//当前按钮下的文本
Text textBtn;

//显示结果的文本
Text textResult;

//音源
AudioSource audioSource;

void Start()
{
	//获取麦克风设备，判断是否有麦克风设备
	if (Microphone.devices.Length > 0)
	{
		isHaveMic = true;
		currentDeviceName = Microphone.devices[0];
	}

	//获取相关组件
	textBtn = this.transform.GetChild(0).GetComponent();
		audioSource = this.GetComponent();
			textResult = this.transform.parent.GetChild(1).GetComponent();
			}

/// 

/// 开始录音
/// 
/// 
/// 
/// 
/// 
public bool StartRecording(bool isLoop = false) //8000,16000
{
	if (isHaveMic == false || Microphone.IsRecording(currentDeviceName))
	{
		return false;
	}

	//开始录音
	/*
	 * public static AudioClip Start(string deviceName, bool loop, int lengthSec, int frequency);
	 * deviceName   录音设备名称.
	 * loop         如果达到长度,是否继续记录
	 * lengthSec    指定录音的长度.
	 * frequency    音频采样率   
	 */

	lastPressTimestamp = GetTimestampOfNowWithMillisecond();

	saveAudioClip = Microphone.Start(currentDeviceName, isLoop, recordMaxLength, recordFrequency);

	return true;
}

/// 

/// 录音结束,返回实际的录音时长
/// 
/// 
public int EndRecording()
{
	if (isHaveMic == false || !Microphone.IsRecording(currentDeviceName))
	{
		return 0;
	}

	//结束录音
	Microphone.End(currentDeviceName);

	//向上取整,避免遗漏录音末尾
	return Mathf.CeilToInt((float)(GetTimestampOfNowWithMillisecond() - lastPressTimestamp) / 1000f);
}

/// 

/// 获取毫秒级别的时间戳,用于计算按下录音时长
/// 
/// 
public double GetTimestampOfNowWithMillisecond()
{
	return (DateTime.Now.ToUniversalTime().Ticks - 621355968000000000) / 10000;
}

/// 

/// 按下录音按钮
/// 
/// 
public void OnPointerDown(PointerEventData eventData)
{
	textBtn.text = "松开识别";
	StartRecording();
}

/// 

/// 放开录音按钮
/// 
/// 
public void OnPointerUp(PointerEventData eventData)
{
	textBtn.text = "按住说话";
	trueLength = EndRecording();
	if (trueLength > 1)
	{
		audioSource.PlayOneShot(saveAudioClip);
		StartCoroutine(_StartBaiduYuYin());
	}
	else
	{
		textResult.text = "录音时长过短";
	}
}

/// 

/// 获取accessToken请求令牌
/// 
/// 
IEnumerator _GetAccessToken()
{
	var uri =
		string.Format(
		"https://openapi.baidu.com/oauth/2.0/token?grant_type=client_credentials&client_id={0}&client_secret={1}",
		apiKey, secretKey);
	UnityWebRequest unityWebRequest = UnityWebRequest.Get(uri);
	yield return unityWebRequest.SendWebRequest();

	if (unityWebRequest.isDone)
	{
		//这里可以考虑用Json,本人比较懒所以用正则匹配出accessToken
		Match match = Regex.Match(unityWebRequest.downloadHandler.text, @"access_token.:.(.*?).,");
		if (match.Success)
		{
			//表示正则匹配到了accessToken
			accessToken = match.Groups[1].ToString();
		}
		else
		{
			textResult.text = "验证错误,获取AccessToken失败!!!";
		}
	}
}

/// 

/// 发起语音识别请求
/// 
/// 
IEnumerator _StartBaiduYuYin()
{
	if (string.IsNullOrEmpty(accessToken))
	{
		yield return _GetAccessToken();
	}

	asrResult = string.Empty;

	//处理当前录音数据为PCM16
	float[] samples = new float[recordFrequency * trueLength * saveAudioClip.channels];
	saveAudioClip.GetData(samples, 0);
	var samplesShort = new short[samples.Length];
	for (var index = 0; index < samples.Length; index++)
	{
		samplesShort[index] = (short)(samples[index] * short.MaxValue);
	}
	byte[] datas = new byte[samplesShort.Length * 2];
	Buffer.BlockCopy(samplesShort, 0, datas, 0, datas.Length);

	string url = string.Format("{0}?cuid={1}&token={2}", "https://vop.baidu.com/server_api", SystemInfo.deviceUniqueIdentifier, accessToken);

	WWWForm wwwForm = new WWWForm();
	wwwForm.AddBinaryData("audio", datas);

	UnityWebRequest unityWebRequest = UnityWebRequest.Post(url, wwwForm);

	unityWebRequest.SetRequestHeader("Content-Type", "audio/pcm;rate=" + recordFrequency);

	yield return unityWebRequest.SendWebRequest();

	if (string.IsNullOrEmpty(unityWebRequest.error))
	{
		asrResult = unityWebRequest.downloadHandler.text;
		if (Regex.IsMatch(asrResult, @"err_msg.:.success"))
		{
			Match match = Regex.Match(asrResult, "result.:..(.*?)..]");
			if (match.Success)
			{
				asrResult = match.Groups[1].ToString();
			}
		}
		else
		{
			asrResult = "识别结果为空";
		}
		textResult.text = asrResult;
	}
}

}