[ot] decklink onair


    Sep 13 2006 | 9:01 pm
    'Blackmagic On-Air 2.0 combines a real time HD mixing console when used with two Intensity boards plugged into Apple Mac Pro systems for a complete live television production studio.'
    How feasible is the option of using two Intensity cards with jitter, for doing for instance realtime mixing of those two HDMI sources ?
    best,
    Gideon

    • Sep 13 2006 | 9:31 pm
      On Sep 13, 2006, at 2:01 PM, Gideon Kiers wrote:
      > How feasible is the option of using two Intensity cards with > jitter, for doing for instance realtime mixing of those two HDMI > sources ?
      I can't speak from experience, but I would imagine as long as they provide QT input components for these cards, that you should be to use jit.qt.grab and be able to transport this data to the GPU) and mix the HD sources with jit.gl.slab without much problem. If you have a chance to test, let us know your findings.
      Thanks, Joshua
    • Sep 13 2006 | 9:41 pm
      I havent tested those specific cards, but I know Decklink and AJA cards work with jit.qt.grab (and GEMs pix_video) without any issues, and provide the whole visible video image, every scanline you want.
      v a d e //
      www.vade.info abstrakt.vade.info
      On Sep 13, 2006, at 5:31 PM, Joshua Kit Clayton wrote:
      > > On Sep 13, 2006, at 2:01 PM, Gideon Kiers wrote: > >> How feasible is the option of using two Intensity cards with >> jitter, for doing for instance realtime mixing of those two HDMI >> sources ? > > I can't speak from experience, but I would imagine as long as they > provide QT input components for these cards, that you should be to > use jit.qt.grab and be able to transport this data to the GPU) and > mix the HD sources with jit.gl.slab without much problem. If you > have a chance to test, let us know your findings. > > Thanks, > Joshua
    • Sep 13 2006 | 9:46 pm
      Ok, would be a v interesting option if it works. The other question is if it would be possible to access the HDMI output of the cards ?
      best,
      On 13-sep-2006, at 23:31, Joshua Kit Clayton wrote:
      > I can't speak from experience, but I would imagine as long as they > provide QT input components for these cards, that you should be to > use jit.qt.grab and be able to transport this data to the GPU) and > mix the HD sources with jit.gl.slab without much problem. If you > have a chance to test, let us know your findings. > > Thanks, > Joshua
      ---------------------------
      Gideon G. Kiers MA/IMM
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    • Sep 13 2006 | 10:21 pm
      On Sep 13, 2006, at 2:46 PM, Gideon Kiers wrote:
      > Ok, would be a v interesting option if it works. The other question > is if it would be possible to access the HDMI output of the cards ?
      Again, if they expose a QT video output component, it should work with jit.qt.videoout. There's nothing DV specific to that object. Note that I doubt that you would be able to address it as an OpenGL display, so it might not be suitable for many purposes aside from simple disk playback.
      Btw, for people looking to record DVI output from their computers, this sounds like a promising option (DVI->HDMI converter box- >Decklink Intensity), relatively low-cost as compared to many of the other RGB frame grabbing options out there.
      -Joshua
    • Sep 13 2006 | 10:34 pm
      On 14-sep-2006, at 0:21, Joshua Kit Clayton wrote:
      > Again, if they expose a QT video output component, it should work > with jit.qt.videoout. There's nothing DV specific to that object. > Note that I doubt that you would be able to address it as an OpenGL > display, so it might not be suitable for many purposes aside from > simple disk playback.
      Indeed. The Onair software does seem to be able to do this, mix 2 inputs to 1 output, not through openGL probably.
      > Btw, for people looking to record DVI output from their computers, > this sounds like a promising option (DVI->HDMI converter box- > >Decklink Intensity), relatively low-cost as compared to many of > the other RGB frame grabbing options out there.
      Exactly. Allthough I'm not 100% sure the Intensity card will be able to deal with this DVI->HDMI conversion properly in f.i. a 1080p resolution. I've sent a mail to the Decklink people, will post their reply if I get any.
      best,
    • Sep 14 2006 | 2:56 pm
      As allways, things are a bit more complicated, here's the blackmagic answer :
      === HDMI output to DVI input
      The HDMI standard provides backward compatibility for DVI signals so you can use and adapter on a DVI port to output to a HDMI display.
      However DVI computer monitors expect 8-bit RGB signals, and DVI signals are always 8-bit RGB. HDMI signals are most commonly 8-bit YUV but could also be RGB and could also be 10 or 12-bit in the latest HDMI 1.3 specification.
      We are currently unaware of any cameras or DVD players which output anything other than 8-bit YUV through their HDMI port. If you were to attach a simple HDMI-to-DVI cable to these devices, they would fail to work with a DVI display.
      Furthermore, DVI computer displays typically work at one frequency which is usually 60 Hz. This contrasts with NTSC and PAL signals which are 29.97 and 25 Hz respectively and are therefore incompatible with DVI computer displays although they should work with DVI TV's which support multiple frequencies.
      In order to guarantee that a HDMI signal can be displayed on a DVI computer monitor, such as an Apple 23" or Dell 24" display, the signal would need to undergo colorspace conversion from YUV to RGB and then pulldown processing would need to be performed on the video frame rate to adapt it to the 60 Hz rate expected by the display. If the HDMI signal was anything other than 8-bit, it would also need to be adapted to 8-bit. I'm sure there are probably expensive convertors which do this but it would make more sense just to use a HDMI display which supports multiple frequencies.
      DVI does not support audio. HDMI supports video and audio.
      === DVI output to HDMI input
      "Does this mean that we can connect the Intensity card to the regular DVI-D output of the graphics card of a second machine, which would be sending out in a 1920 x 1080 resolution ? Have you tested this option in your labs ?"
      We thought of that but so far have been unable to find a graphics card which outputs at standard TV resolutions such as 1920 x 1080, 1280 x 720, 720 x 486 and 720 x 576. If we could find one, then I would expect we could capture it with Intensity using a DVI to HDMI adapter on the graphics card output.
      If you aware of such a graphics card, please let us know the brand and model as we'd love to get one and test it. I realize you can directly connect a big screen TV to the DVI output of computers but if you check the resolution being used, it will not be a TV resolution.
      On 14-sep-2006, at 0:21, Joshua Kit Clayton wrote:
      > Btw, for people looking to record DVI output from their computers, > this sounds like a promising option (DVI->HDMI converter box- > >Decklink Intensity), relatively low-cost as compared to many of > the other RGB frame grabbing options out there.
    • Sep 14 2006 | 3:42 pm
      Hello,
      Maybe using converter boxes ?
      CP-261H / PC/HD with Audio to HDMI Format Converter http://tinyurl.com/jcnyg
      CP-267 / HDMI to DVI converter w/Digital Audio http://tinyurl.com/zdptz
      Bertrand
      2006/9/14, Gideon Kiers : > As allways, things are a bit more complicated, here's the blackmagic > answer : > > === HDMI output to DVI input > > The HDMI standard provides backward compatibility for DVI signals so > you can > use and adapter on a DVI port to output to a HDMI display. > > However DVI computer monitors expect 8-bit RGB signals, and DVI > signals are > always 8-bit RGB. HDMI signals are most commonly 8-bit YUV but could > also be > RGB and could also be 10 or 12-bit in the latest HDMI 1.3 specification. > > We are currently unaware of any cameras or DVD players which output > anything > other than 8-bit YUV through their HDMI port. If you were to attach a > simple > HDMI-to-DVI cable to these devices, they would fail to work with a DVI > display. > > Furthermore, DVI computer displays typically work at one frequency > which is > usually 60 Hz. This contrasts with NTSC and PAL signals which are > 29.97 and > 25 Hz respectively and are therefore incompatible with DVI computer > displays > although they should work with DVI TV's which support multiple > frequencies. > > In order to guarantee that a HDMI signal can be displayed on a DVI > computer > monitor, such as an Apple 23" or Dell 24" display, the signal would > need to > undergo colorspace conversion from YUV to RGB and then pulldown > processing > would need to be performed on the video frame rate to adapt it to the > 60 Hz > rate expected by the display. If the HDMI signal was anything other than > 8-bit, it would also need to be adapted to 8-bit. I'm sure there are > probably expensive convertors which do this but it would make more sense > just to use a HDMI display which supports multiple frequencies. > > DVI does not support audio. HDMI supports video and audio. > > === DVI output to HDMI input > > "Does this mean that we can connect the Intensity card to the regular > DVI-D output of the graphics card of a second machine, which would be > sending out in a 1920 x 1080 resolution ? Have you tested this option > in your labs ?" > > We thought of that but so far have been unable to find a graphics > card which > outputs at standard TV resolutions such as 1920 x 1080, 1280 x 720, > 720 x > 486 and 720 x 576. If we could find one, then I would expect we could > capture it with Intensity using a DVI to HDMI adapter on the graphics > card > output. > > If you aware of such a graphics card, please let us know the brand > and model > as we'd love to get one and test it. I realize you can directly > connect a > big screen TV to the DVI output of computers but if you check the > resolution > being used, it will not be a TV resolution. > > On 14-sep-2006, at 0:21, Joshua Kit Clayton wrote: > > > Btw, for people looking to record DVI output from their computers, > > this sounds like a promising option (DVI->HDMI converter box- > > >Decklink Intensity), relatively low-cost as compared to many of > > the other RGB frame grabbing options out there. >
    • Sep 14 2006 | 3:53 pm
      yes, interesting. allthough i believe the problem is more the resolution possibilities of the graphics card, then the converter (for dvi to hdmi/intensity) ?
      On 14-sep-2006, at 17:42, bertrand wrote:
      > CP-261H / PC/HD with Audio to HDMI Format Converter > http://tinyurl.com/jcnyg
    • Sep 14 2006 | 7:59 pm
      Hola, I'm looking for a some advicer in the general direction of manipulating live DV input to look something close to atomic microscope imagery. I've come up with a few "not-so-great' patches using Video->Nurbs patch as a starting point. These are using existing footage but not live.. Any ideas? All the best, Stuart Smith