新增解析的js

2025-07-16 18:34:49 +08:00
parent 122208d9cb
commit 596760a707
9 changed files with 2153 additions and 15 deletions
--- a/public/textVideo/wav.js
+++ b/public/textVideo/wav.js
@ -0,0 +1,86 @@
+/*
+wav编码器+编码引擎
+https://github.com/xiangyuecn/Recorder
+
+当然最佳推荐使用mp3、wav格式，代码也是优先照顾这两种格式
+浏览器支持情况
+https://developer.mozilla.org/en-US/docs/Web/HTML/Supported_media_formats
+
+编码原理：给pcm数据加上一个44直接的wav头即成wav文件；pcm数据就是Recorder中的buffers原始数据（重新采样），16位时为LE小端模式（Little Endian），实质上是未经过任何编码处理
+*/
+(function(){
+"use strict";
+
+Recorder.prototype.enc_wav={
+	stable:true
+	,testmsg:"支持位数8位、16位（填在比特率里面），采样率取值无限制"
+};
+Recorder.prototype.wav=function(res,True,False){
+		var This=this,set=This.set
+			,size=res.length
+			,sampleRate=set.sampleRate
+			,bitRate=set.bitRate==8?8:16;
+		
+		//编码数据 https://github.com/mattdiamond/Recorderjs https://www.cnblogs.com/blqw/p/3782420.html https://www.cnblogs.com/xiaoqi/p/6993912.html
+		var dataLength=size*(bitRate/8);
+		var buffer=new ArrayBuffer(44+dataLength);
+		var data=new DataView(buffer);
+		
+		var offset=0;
+		var writeString=function(str){
+			for (var i=0;i<str.length;i++,offset++) {
+				data.setUint8(offset,str.charCodeAt(i));
+			};
+		};
+		var write16=function(v){
+			data.setUint16(offset,v,true);
+			offset+=2;
+		};
+		var write32=function(v){
+			data.setUint32(offset,v,true);
+			offset+=4;
+		};
+		
+		/* RIFF identifier */
+		writeString('RIFF');
+		/* RIFF chunk length */
+		write32(36+dataLength);
+		/* RIFF type */
+		writeString('WAVE');
+		/* format chunk identifier */
+		writeString('fmt ');
+		/* format chunk length */
+		write32(16);
+		/* sample format (raw) */
+		write16(1);
+		/* channel count */
+		write16(1);
+		/* sample rate */
+		write32(sampleRate);
+		/* byte rate (sample rate * block align) */
+		write32(sampleRate*(bitRate/8));// *1 声道
+		/* block align (channel count * bytes per sample) */
+		write16(bitRate/8);// *1 声道
+		/* bits per sample */
+		write16(bitRate);
+		/* data chunk identifier */
+		writeString('data');
+		/* data chunk length */
+		write32(dataLength);
+		// 写入采样数据
+		if(bitRate==8) {
+			for(var i=0;i<size;i++,offset++) {
+				//16转8据说是雷霄骅的 https://blog.csdn.net/sevennight1989/article/details/85376149 细节比blqw的按比例的算法清晰点，虽然都有明显杂音
+				var val=(res[i]>>8)+128;
+				data.setInt8(offset,val,true);
+			};
+		}else{
+			for (var i=0;i<size;i++,offset+=2){
+				data.setInt16(offset,res[i],true);
+			};
+		};
+		
+		
+		True(new Blob([data.buffer],{type:"audio/wav"}));
+	}
+})();