Unity中播放带有alpha通道格式为Mp4的视频

Shader "Unlit/NewUnlitShader"
{
	Properties
	{
		_Color("Color", Color) = (1,1,1,1)
		//_MainTex ("Albedo (RGB)", 2D) = "white" {}  
		_AlphaVideo("Alpha Video(R)", 2D) = "white" {}
		_Glossiness("Smoothness", Range(0,1)) = 0.5
		_Metallic("Metallic", Range(0,1)) = 0.0
	}
		SubShader
		{
		Tags { "Queue" = "Transparent" "RenderType" = "Transparent" }
			LOD 200

			CGPROGRAM
			// Physically based Standard lighting model, and enable shadows on all light types  
			#pragma surface surf Standard alpha  

			// Use shader model 3.0 target, to get nicer looking lighting  
			#pragma target 3.0  

			sampler2D _MainTex;
			sampler2D _AlphaVideo;

			struct Input {
				float2 uv_MainTex;
				float2 uv_AlphaVideo;
			};

			half _Glossiness;
			half _Metallic;
			fixed4 _Color;

			void surf(Input IN, inout SurfaceOutputStandard o) {
				// Albedo comes from a texture tinted by color  
				fixed4 c = tex2D(_MainTex, IN.uv_MainTex) * _Color;
				fixed4 _alpha = tex2D(_AlphaVideo, IN.uv_AlphaVideo);
				o.Albedo = c.rgb;
				// Metallic and smoothness come from slider variables  
				o.Metallic = _Metallic;
				o.Smoothness = _Glossiness;
				o.Alpha = _alpha.r;

			}
			ENDCG
		}
			FallBack "Diffuse"
}

using System.Collections;
using System.Collections.Generic;
using UnityEngine.UI;
using UnityEngine;
public class Juasd : MonoBehaviour {
    public MovieTexture moveTex;
    
	// Use this for initialization
	void Start () {
        GetComponent().material.mainTexture = moveTex;
        moveTex.loop = true;
        moveTex.Play();
        

    }
	
	// Update is called once per frame
	void Update () {
		
	}
}