[Tig] Vialta?

Martin Euredjian ecinema
Sat Feb 23 22:08:28 GMT 2002

OK, here's another technical question.  I've asked Sony just a couple of
these questinos but I haven't been succesful getting an answer:

I've been told that the Vialta can do "2K scans" in real time and output via
a dual-link HDSDI setup.

The questions are:

1-  Being that HDSDI, as defined in SMPTE 292M-1998 cannot carry any payload
that utilizes code words between h'000 and h'003 and between h'3FC and
h'3FF; How is it that the Vialta can transport image information that most
certainly needs to use these code values?

2- Is some sort of a non-conventional link used?

3- Is the ANC data space utilized in any way?

4- Is there an interface box that converts this dual HDSDI link to Fibre
Channel or SCSI or?

5- How is the header information handled?  Is there a workstation attachment
to a Vialta that permits one to manage this data?

6- The header on a Cineon or DPX file (very similar, cineon having a subset
of the data in DPX) can carry all kinds of useful information, even a
thumbnail image of the larger payload.  If there is no external box or
workstatino to deal with this, how is it handled?  How are timecode,
keykode, etc, encoded and transmitted over a dual HDSDI link given the link
constraints presented in (1) above?

7-  Are the cineon data scans created by a Vialta 1920 x 1080 RGB or 2048 x
1536 RGB?  If the latter, how is the interpolation handled?

8- Being that the aspect ratio of a true 2K scan is 1:33 and not 16:9 the
internal upconversion would have to go start with 1440 pixels of horizontal
resolution and synthesize from 1440 to 2048 and from 1080 to 1536.  Is this
what happens?

I would appreciate understanding how the above is handled.  Thanks in
advance for any/all replies.  Please post to the TIG so that others may
benefit from the explanations.

Stepping away from the Vialta for a moment.  This scanning business
brings-up something that I like about the CRT-based technologies (CReality
and Millenium) which is the ability to modify the scan for different aspect
ratio scans and not necessarily loose resolution or have to synthesize data.
It's been a while, so I don't remember, but presumably, if I wanted to scan
a piece of film at 2.35:1 into a DPX file and do so at 3609 x 1536 all
indications are that it could be done.  Can someone confirm this?


Martin Euredjian
eCinema Systems, Inc.
(661) 305-9320
ecinema at pacbell.net

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