ts-in-net
			var n=((arr[j++] | (arr[j++]<<8) | (arr[j++]<<16))<<8)>>8;
			n=n/16777216;
			//浮点数转成16位
			res[i++]=n*0x7FFF;
		};
	}else if(bitRate==32){
		var f32=new Float32Array(arr.buffer.slice(0,arr.length-arr.length%4));
		var res=new Int16Array(f32.length);
		for(var j=0;j<f32.length;j++){//floatTo16BitPCM 
			var s=Math.max(-1,Math.min(1,f32[j]));
			s=s<0?s*0x8000:s*0x7FFF;
			res[j]=s;
		};
	}
	
	
	var resA=res;
	var resB=res;
	if(numChannels==2){
		//分离声道
