White noise ( grain filter ) shader in unity

WhiteNoise.shader

Shader "BitShiftProductions/Noises"
{
	Properties
	{
		_MainTex("Texture", 2D)="white"
		_NoiseScale("Noise Scale",Float) = 5.0
		_Strength("Noise Strength",Float) = 1.0
	}
	SubShader
	{
		Tags { "RenderType"="Opaque" }

		Pass
		{
			CGPROGRAM
			#pragma vertex vert
			#pragma fragment frag
			
			#include "UnityCG.cginc"

			struct appdata
			{
				float4 vertex : POSITION;
				float2 uv : TEXCOORD0;
			};

			struct v2f
			{
				float2 uv : TEXCOORD0;
				float4 vertex : SV_POSITION;
			};

			sampler2D _MainTex;
			float _NoiseScale;
			float _Strength;
			
			v2f vert (appdata v)
			{
				v2f o;
				o.vertex = UnityObjectToClipPos(v.vertex);
				o.uv = v.uv;
				return o;
			}

			float random( float2 p )
			{
				return frac(sin(dot(p.xy,float2(_Time.y,65.115)))*2773.8856);
			}
			fixed4 frag (v2f i) : SV_Target
			{
				float2 normUV = i.uv; 
				normUV *= _NoiseScale; // Scale the coordinate system by 10
			    float2 ipos = floor(normUV);  // get the integer coords

			    // Assign a random value based on the integer coord
			    float rand = random(ipos);
			    fixed4 col = fixed4(rand,rand,rand,1.0);
			    col = lerp( tex2D(_MainTex,i.uv),col,_Strength);
			    return col;
			}

			ENDCG
		}
	}
}