Distribution of video signal to multiple TV using a matrix

["C" <thespade13YOUneed2removethis@xxxxxxxx>]

Good Day
New problem for me.  I know very little about video signal so ''Any help is
welcomed''.

I would like to distribute video through my house, but nothing fancy.  I
already have a video matrix (8 inputs & 8 outpouts) that can display any
inputs to any outputs.  The matrix accepts only composite video and audio
(left and right).  The actual matrix:
http://shinybowusa.com/shop/product_info.php?products_id=47&osCsid=adffd7e6c4a68004be9102a284d13daf


I have 3 inputs:

1- Regular cable (Coax with f-type connector);
2- Digital cable (Composite video and audio);
3- DVD (Composite video and audio).

I have no problem with #2 and 3.  I can process them through the matrix and
it works ok.


How do I feed the matrix with standard cable (input #1)?   What I would like
to have is that the input go into the matrix then to multiples TV and have
each TV on a different channel.  That would mean that the original signal,
the one that carries 'all channels' on the coax from the cable provider is:
   1) changed into Composite video and audio;
   2) processed by the matrix;
   3) spitted out of the matrix to multiples outputs;
   4) carried to the multiples tv;
   5) each tv can select the channel.

Is that possible?  Any idea how I can acheive that?

A side question to my problem: is 50ft too long to carry composite video?

Thank you for reading and helping.

Chris