How to make a cheap analog switch pass analog video signals?

[HSPalm]

I want to use this cheap video switch to pass analog video signals: https://www.digikey.com/product-detail/en/texas-instruments/74LVC1G3157DBVRE4/74LVC1G3157DBVRE4-ND/1688785
But it can only pass signals from 0v to Vcc. Composite video signals often swing below 0v. Can I cheat by raising the switch gnd potential with a voltage divider?

[Zero999]

All analogue switches can only switch signal voltage within the power supply rails, unless it includes an in-build voltage doubler.

The usual way to do this is to bias the signal at half the supply voltage and AC couple it.

[HSPalm]

Thanks for replying. BTW, I also just realized how my proposed solution was completely not an alternative because I would really just even raise the gnd potential and make the video signal run even "lower".

[Mechatrommer]

mechanical relay works on almost any voltages, but if mechanical is not your taste, you can cheat by supplying the IC with dual rail supply, ie IC's gnd = -ve voltage. not looking at the IC's datasheet, but if the IC doesnt have drain capability then you may need to homebrew, simply like pull down resistor to -ve rail, ymmv.

[HSPalm]

mechanical relay works on almost any voltages, but if mechanical is not your taste, you can cheat by supplying the IC with dual rail supply, ie IC's gnd = -ve voltage. not looking at the IC's datasheet, but if the IC doesnt have drain capability then you may need to homebrew, simply like pull down resistor to -ve rail, ymmv.

Relay no can do, I'm trying to switch graytones in between lines on video frames. Thanks for your input. I was hoping for a very small design so I think I may prefer the biasing voltage way.

[Kleinstein]

The CMOS switches only work for signals within there supply and maybe some 100 mV beyond.
There are some that have an extra negative supply, like the 74HC5053. So you can have 0 ond 5 V for the control signal and -5 to +5 V signal range.

[PChi]

Yes you can cheat by adding bias resistors and AC coupling the video signal with a large enough capacitor. I beleive that most monitors used a 'black level clamp' circuit that set the internal 'DC' level during blanking back to the black level. I used 4066 CMOS switches in a crappy video multiplexer many years ago and that is what I did.