Langchain-Chatchat/views/src/views/chat/voicekeda/kedatts/transcode.worker.js

let minSampleRate = 22050
self.onmessage = function(e) {
	transcode.transToAudioData(e.data)
}
var transcode = {
	transToAudioData: function(audioDataStr, fromRate = 16000, toRate = 22505) {
		let outputS16 = transcode.base64ToS16(audioDataStr)
		let output = transcode.transS16ToF32(outputS16)
		output = transcode.transSamplingRate(output, fromRate, toRate)
		output = Array.from(output)
		self.postMessage({
			data: output,
			rawAudioData: Array.from(outputS16)
		})
	},
	transSamplingRate: function(data, fromRate = 44100, toRate = 16000) {
		var fitCount = Math.round(data.length * (toRate / fromRate))
		var newData = new Float32Array(fitCount)
		var springFactor = (data.length - 1) / (fitCount - 1)
		newData[0] = data[0]
		for (let i = 1; i < fitCount - 1; i++) {
			var tmp = i * springFactor
			var before = Math.floor(tmp).toFixed()
			var after = Math.ceil(tmp).toFixed()
			var atPoint = tmp - before
			newData[i] = data[before] + (data[after] - data[before]) * atPoint
		}
		newData[fitCount - 1] = data[data.length - 1]
		return newData
	},
	transS16ToF32: function(input) {
		var tmpData = []
		for (let i = 0; i < input.length; i++) {
			var d = input[i] < 0 ? input[i] / 0x8000 : input[i] / 0x7fff
			tmpData.push(d)
		}
		return new Float32Array(tmpData)
	},
	base64ToS16: function(base64AudioData) {
		base64AudioData = atob(base64AudioData)
		const outputArray = new Uint8Array(base64AudioData.length)
		for (let i = 0; i < base64AudioData.length; ++i) {
			outputArray[i] = base64AudioData.charCodeAt(i)
		}
		return new Int16Array(new DataView(outputArray.buffer).buffer)
	},
}