Looking for a way to pack 4 bytes of color data into a float in shader lab

Unity Engine
3

Here’s the full code, along with the comment about limitations:

// Encoding/decoding [0..1) floats into 8 bit/channel RGBA. Note that 1.0 will not be encoded properly.
inline float4 EncodeFloatRGBA( float v )
{
	float4 kEncodeMul = float4(1.0, 255.0, 65025.0, 160581375.0);
	float kEncodeBit = 1.0/255.0;
	float4 enc = kEncodeMul * v;
	enc = frac (enc);
	enc -= enc.yzww * kEncodeBit;
	return enc;
}
inline float DecodeFloatRGBA( float4 enc )
{
	float4 kDecodeDot = float4(1.0, 1/255.0, 1/65025.0, 1/160581375.0);
	return dot( enc, kDecodeDot );
}
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