[Tig] TIG Piccasso

Sebastian Sylwan sebastian
Tue May 14 09:16:44 BST 2002

Hi all,

I'm replying here as a user not as a representative of Snell&Wilcox and so 
my information may not be precise.

The SpiRINT (which is the architecture on which the picasso software runs) 
is inherently a Dual-link HD-SDI machine. it deals with RGB data and at the 
moment is limited by 1920x1080. The underlying system though could handle 
2K images and the people from s&w have told me that they are working on 
this (i hope i'm not stepping into anybody's toes here). My personal 
opinion is that the increasing complexity of the systems we deal with 
everyday together with the (yes i will use the infamous buzz-word) 
convergence of IT & video technologies (and markets) makes it really 
difficult to rely on rock-carved definitions. The primaries/secondaries 
discussion a while ago proved the same point IMHO. Back to the SpiRINT as 
far as i know (and would expect) the only data that get recorded on the 
disks is the actual frames (wouldn't make sense to have "sync" signals) and 
maybe some metadata. We're not talking composite VTR's, the sync gets 
generated when the data is played back in real time. From another point of 
view you might see it as a DDR with realtime dual link HD-SDI I/O (waiting 
for the 2k and HSDL... ).



At 19.23 13/05/2002 -0400, Rita Swinson wrote:
>Participate in the open TIG webspace, a collaborative 
>project.  http://tig.alegria.com/twiki/bin/view
>As usual thru you for the TIG !
>Subject Piccasso Thread.
>I don't know whether I will now confuse or clarify this thread. But I
>believe it is worth identifying the Video and Data elements as seen from
>Cintel's perspective..
>HD-SDI is pure video, it has H & V sync information as part of each frame,
>which means sync can be recovered on each line if a problem occurs,  and
>HD-SDI comes in many interlace and progressive guises. Most HD telecines
>can output Y,Cr,Cb or RGB in HD 4:2:2 or HD 4:4:4.and in 8 or 10 bit.  None
>of these can be regarded as data. Dual Link HD-SDI as has been explained
>elsewhere is a double cable allowing HD 4:4:4 plus full bandwidth alpha
>channel, as opposed to HD 4:2:2 down a single cable.
>Data transfers, normally regarded as RGB  2K (2048 x 1536 or 1556) and 4K
>(4096 x 3112) have no embedded sync surronding the signal. Each frame is
>unique and bit depths can be from 8 to 14 bit. There are many  potential
>formats but today DPX is the commonest. "Sync" is a matter of the image
>files being sequentially named, or some form of associated metadata. This
>implies if you loose "sync" you loose whole frames !
>While data is normally transported  over Hippi, LVDS, Ethernet or future
>GSN there is another transport method that  "melds" the technologies of
>HD-SDI and Data.
>This  is HSDL (High Speed Data Link). Basically where a dual link HD
>infrastructure exists, then why not convert 2K (2048 x 1536) data into a
>dual steam that looks like Dual HD +Alpha channel to HD devices. Now in
>truth it is not Dual HD  nor can it be viewed on HD monitors, the data is
>just constructed to fool Dual HD-SDI systems into recording it and playing
>it back.  And the advantage ?  Well HD devices are about the fastest
>digital equipment around and an HSDL system can record and playback real
>2048 x 1536 10 bit RGB images at around 15 fps.  Certain color corrector
>manufacturers can recognise and correct  HSDL at these rates, however it
>must be remembered that, at some stage the real film data world will
>require the HSDL "data" to be converted to conventional DPX or similar.
>Reading the TIG thread I gather that Piccasso is a Dual Stream HD-SDI
>device, and that it has, according to Martin Holmes, an internal structure
>in DPX. If this is the case then can  2K (2048 x 1536 or 1556)  10 bit RGB
>files be output to the real world as DPX ?  Does Piccasso recognise the
>HSDL structure and have an ability to convert to DPX ?  Or is it a 1920
>x1080 HD SDI only device as Nigel Hadley implies.? If it is 1920 x 1080
>only, then despite its RGB 10 bit 4:4:4 capability it is, in my opinion,
>confusing to refer to it as a data device.
>Life is never simple, our industry even less so.
>Peter Swinson
>Cintel International
>No marketing or advertising on the tig.  (help wanted ads excepted)
>Send such submissions to rob at tig.alegria.com.
>...and beware any posts to this mailinglist that appear
>  to promote products without disclaiming financial interest.
>Thank you Bill Laverty for supporting the TIG.
>copyright TIG 2002 all rights reserved.

Sebastian Sylwan                                           sebastian at vrmmp.it
Direttore Tecnologico - Chief Technology Officer           Tel. +390112271211
Virtual Reality & Multi Media Park S.p.A.                 http://www.vrmmp.it

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