ITU-R BT 656

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Hello!

Can anyone help me validate (true/false) the following statements:


  "Using the to put video information into a
   digital system, I don't need to take care of any of the
   vertical and/or horizontal synchronization pulses, as they
   are embedded in the data stream"

  "Using the 8-bit parallel version of the ITU-R BT 656, I only need
   9 inputs (including clock @ 27 MHz) from my FPGA to get the
   video stream into the device."


Thanks!

Fran.

Re: ITU-R BT 656

Sorry for the mistake:

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                   ITU-R_BT_65

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Re: ITU-R BT 656

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True: Syncs are embedded and have values 0 and 255.
True: 656 Parallel data uses a bus of 9 pairs balanced ECL at 100 ohms. I
guess you'll need line drivers for this.

Peter



Re: ITU-R BT 656

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Mowcowmoo is correct but I would go on to say that in the modern world most
studio 656 interconnect is done in 10 bits rather than 8 as a modulated
bit serial stream on coax at 270 Mb/s.  This is usually called SDI.

You should really find out what you are trying to interface to with the 656
stream before you commit to the older 8-bit parallel interface.

Re: ITU-R BT 656
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I am actually getting the video input from a PAL decoder (Philips SAA7111A)
and putting it back  to a similar encoder to see the video out. So, I don't
use the stadard for transimission purposes, but only interfacing.

Thanx to both of you.

Re: ITU-R BT 656
On Wed, 26 Nov 2003 16:16:26 +0100, Francisco Camarero

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YES

YES

... one small warning , if you intend to generate the 27mhz on the
fpga, send it to the decoder, have the decoder output 27mhz clk clock
the data into the fpga ... be warned that depending upon the decoder
and video the decoder output clock can be quite  jittery and cause
problems .. you may want to consider implementing a small fifo on the
input video data to have a solid output ...


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