HD Tivo Alternative input?

I’m sure somebody has done this before… I have an HD Tivo with 2 CableCards. I’m trying to run my DVD player as an input so I can put my movies on Tivo and use the room-to-room feature to watch movies on other Tivo devices (I have two units).

I tried an RF modulator, to put the signal on Channel 3 but that doesn’t work because the Tivo is only seeing the signal as digital, not analog.

What other choices do I have? Can I plut another device into the Tivo via USB and run a hack or something?

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