2:1 stereo mixer/ ch1 mutes channel 2Hello

[bjam03]

Hello all, I would like to build a circuit which takes 2 line level stereo signals in and output's one with the condition:
Input 1 is output until there is a signal on input 2, in which case input 1 is muted and input 2 is output OR
Input 1 is attenuated and mixed with full strength Input 2.
Does anyone know of a IC which can perform this requirement?
Thanks!
B.

 

[audioguru2]

An IC is designed and produced when there is enough demand for it so the manufacturer can make some profit from it.
You might be the only person who needs an IC to do what you want so I doubt if there is one or that there will ever be one.

You or somebody could design a circuit to do it.