[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [TIG] What is Legal?

We at Roland House agree with Dave's assessment of legal/non-legal 
levels. For this reason we base legal levels not on the Y,R-Y,B-Y parade, 
or the double diamond, but on the vector (X-Y) display of the color 
diference signals, referenced to 75% color bars. This is compatible with 
SMPTE/EBU N-10 levels. Since both RGB and Y,R-Y, B-Y allow levels that 
are illegal when encoded. It seems prudent to monitor composite 
compatible as described above. As for standards, There will be arguments 
against a 75% standard on the grounds that it limits chroma range, 
causing more aliasing (more of an issue in 8bit 601 than 10 bit). This 
explains all of the 100% chroma material that we get from Europe. We 
would also like to see some standards, though. Vince  

Dave Corbitt wrote:
>                       Subject:                              Time:  10:11 AM
>   OFFICE MEMO         What is Legal?                        Date:  5/20/96
> Fellow TIG members,
> I think SMPTE, the EBU, and our Post Production industry need to come up with
> guidelines and recommended practices for exactly what constitutes "LEGAL" for
> recorded video signals be they on a D-1 or Composite format, 525 or 625.