What kind of issues are you guys having converting from dvi to hdsdi? I think I will more than likely be doing this in the not so distant future and since you mentioned issues I thought I would ask. On a side note I have noticed that matrox is releasing some new sdi output cards for mac but I dont know if they support openGl etc.
Here is a link: http://www.matrox.com/video/en/press..._multi_io_mac/
If you read the article it would seem that these devices are targeted toward what we do with catalyst. You guys have any input on these?
There are also input cards and cards that do i/o.... would be amazing if these were actually suitable? your thoughts Richard?
BTW... these fit in an xserve supposedly
The biggest issue is having consistent color. Using a scope to test the HD-SDI out from a converted mac shows tons of illegal colors. Also, matching the color is a pain. Sync is an issue as well as frame delay. Since a mac is 60Hz, the multiple is 30fps which is not 59.94 or 29.97 so every 10 seconds is a subtle frame skip. It works but if your director takes Cat as a direct broadcast feed, then the producers won't be happy.
I'll probably get and test the first HD-SDI solution that does 59.94 with broadcast color as an output option.
Still though, for all the companies using HD-SDI as their primary pipeline to the projection sources, a video card that works would be great.
A card that fits in an xServe is great compared to trying to shoehorn a card that doesn't and having apple reject support because of it.
SourceChildTODD SCRUTCHFIELD
...if it ain't broke...
gimme 5 and then don't act surprised
normal hdsdi - is a lower quality output signal than rgb 4:4:4 from a dvi or vga monitor-
describing an RGB monitor as displaying illegal colour in YUV colour space is
the wrong way round-
normal HDSDI cannot display a full resolution RGB 4:4:4 signal - whatever the refresh rate-
-
HDSDI is YUV encoded and 4:2:2 - same old broadcast bandwidth limiting exercise-
the conversion from RGB to YUV is never lossless - hdsdi is downsampled- its worse than DVI/VGA not better
DVI/vga is higher quality than hdsdi...
broadcast colour is lower quality than RGB 444- i think you have been taking the wrong broadcast based medicine...
http://en.wikipedia.org/wiki/Serial_digital_interface
the use of 29.97 and all the insane resulting confusing is just so confusing to everyone. its not an advantage of hdsdi - its an albatross.For all serial digital interfaces (excluding the obsolete composite encodings), the native color encoding is 4:2:2 YCbCr format. The luminance channel (Y) is encoded at full bandwidth (13.5 MHz in 270 Mbit/s SD, ~75 MHz in HD), and the two chrominance channels (Cb and Cr) are subsampled horizontally, and encoded at half bandwidth (6.75 MHz or 37.5 MHz). The Y, Cr, and Cb samples are co-sited (acquired at the same instance in time), and the Y' sample is acquired at the time halfway between two adjacent Y samples.
Yep, it sure is. Richard is right.
Sadly, most broadcast systems use HDSDI as their primary interface.
Honestly, there's no problem until there is a need to have color continuity between a Playback deck and a media server.
Believe me, there's nothing worse than having to match footage and having a video engineer arguing wrong points. Then you get the content creators who complain because their creations look different from one medium to another when they themselves don't even understand Or apply Color Space.
However, theses are all issues which come into play when forced to convert to HDSDI.
But then again, neither can most codecs. It's a loosing battle.
It's all propaganda fed to media server people by broadcast engineers to justify the need to keep using interlaced.
THEIR ALL OUT TO GET US!!!! RUN!
The biggest Albatross of all is a $150k HD video projector that has a fiber input and the video company demands to use HDSDI.
SourceChildTODD SCRUTCHFIELD
...if it ain't broke...
gimme 5 and then don't act surprised
I havent heard back from the sales engineer I tried to contact regarding those cards... you know anything about them? Or any other solution for that matter. That sync issue you speak of is killing me as well. A broadcast friendly output from catalyst needs to happen.
I don't know yet. Too many things on my plate to jump at right away.
Honestly, use an ImagePro or a TVOne Scaler. Richard said it best. The whole thing is an albatross. If you can stay DVI or VGA then do so. Fibre extension is a wonderful thing.
If you Must integrate into broadcast, use an ImagePro.
SourceChildTODD SCRUTCHFIELD
...if it ain't broke...
gimme 5 and then don't act surprised
frame rates depend entirely on whether you can set the edid to work at hdsdi frame rates.
that depends on your scan convertor-
edid tells computer what it wants to output
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All colour space conversions discussions are moot/pointless/endless and affect all systems across the board - in every industry with a colour output device-
printer- video deck - monitor - lcd -projector -art -its been this way since the first time anyone tried to make a colour image... even painters have colour space problems
how that conversion is done is dependant on the box you are using to do the conversion from dvi/vga to hdsdi-
There is no universal/lossless colour space it affects everyone in broadcast print or post -production.
doesnt depend on quality or cost.
http://en.wikipedia.org/wiki/Color_space
http://dx.sheridan.com/advisor/cmyk_color.html
and in video world there is the YUV RGB conversion problem as well and colour sub-sampling-
http://en.wikipedia.org/wiki/YUV
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ultimately colour is perceptual - its not technical problem.
it kindof really doesnt matter because the eye will do its own thing anyway-
vision is all about context -
there is no absolute colour in the eye.
look at this optical illusion
http://www.michaelbach.de/ot/lum_ade...dow/index.html
the eye cant even determine the tonal value of 2 squares accurately in the same image....
the 2 squares look completely different tonally - but are the same...