robin.meier

i'm rendering openGL stuff on two different machines (mac pro's). i would now like to concatenate the two generated images in order to project them with just one projector.

i have a third mac pro standing around, which i could use for this. so i have been looking into jit.qt.videoout but the readback GPU-CPU is VERY slow.

does anyone have an idea how i can get the two images onto the same projector?

video-out-in-for-macs

One solution would put you at 2x SD inputs on the macpro -- 2 

DFG-1394's each taking s-video in on the third machine, then glue 

A more solid solution would be to use a hardware 'seamless graphics 

switcher' such as TVOne, Folsom Research or Analog Way, this would 

let you mix/scale/side by side 2 vga or dvi inputs - but this is 

costly, although maybe not so bad to rent for a night or a week.

but it seems like trying to render both openGL stuffs on a single 

> i'm rendering openGL stuff on two different machines (mac pro's). i 

> would now like to concatenate the two generated images in order to 

> i have a third mac pro standing around, which i could use for this. 

> so i have been looking into jit.qt.videoout but the readback GPU- 

> does anyone have an idea how i can get the two images onto the same 

One solution would put you at 2x SD inputs on the macpro -- 2  
DFG-1394's each taking s-video in on the third machine, then glue  
them together for 1280x480

A more solid solution would be to use a hardware 'seamless graphics  
switcher' such as TVOne, Folsom Research or Analog Way, this would  
let you mix/scale/side by side 2 vga or dvi inputs - but this is  
costly, although maybe not so bad to rent for a night or a week.

but it seems like trying to render both openGL stuffs on a single  
machine would be the optimal solution.

> i'm rendering openGL stuff on two different machines (mac pro's). i  
> would now like to concatenate the two generated images in order to  
> project them with just one projector.
>
> i have a third mac pro standing around, which i could use for this.  
> so i have been looking into jit.qt.videoout but the readback GPU- 
> CPU is VERY slow.
>
> does anyone have an idea how i can get the two images onto the same  
> projector?
>
> any help very appreciated!
> gracias,


What is the reason that you want to do the opengl rendering on two different machines? GPU performance maximum? If not, it is possibly better to have the two machines send low-level rendering commands to the third machine via ethernet (after dealing with the user interface, all kinds of calculations, etc) and let the third machine do the rendering.

On the other hand I am interested in the best way (especially with the smallest latency) to get any video from one computer into another. I'm a noob at this. Would it really be necessary to convert to analogue and back, Johnny?

I never really understood the jit.qt.videoout object. It needs a separate device. This is probably naive but shouldn't it be possible to simply stream the video to a firewire port, connect it with a firewire cable to the other computer and grab it with jit.qt.grab?

Quote: robin.meier wrote on Sat, 24 March 2007 18:27

----------------------------------------------------

> i'm rendering openGL stuff on two different machines (mac pro's). i would now like to concatenate the two generated images in order to project them with just one projector.

> i have a third mac pro standing around, which i could use for this. so i have been looking into jit.qt.videoout but the readback GPU-CPU is VERY slow.

> does anyone have an idea how i can get the two images onto the same projector?

On the other hand I am interested in the best way (especially with the smallest latency) to get any video from one computer into another. I'm a noob at this. Would it really be necessary to convert to analogue and back, Johnny? 

Quote: robin.meier wrote on Sat, 24 March 2007 18:27
----------------------------------------------------
> jittery friends!
>
> i'm rendering openGL stuff on two different machines (mac pro's). i would now like to concatenate the two generated images in order to project them with just one projector.
>
> i have a third mac pro standing around, which i could use for this. so i have been looking into jit.qt.videoout but the readback GPU-CPU is VERY slow.
>
> does anyone have an idea how i can get the two images onto the same projector?
>
> any help very appreciated!
> gracias,
>
> robin
----------------------------------------------------


> On the other hand I am interested in the best way (especially with 

> the smallest latency) to get any video from one computer into 

> another. I'm a noob at this. Would it really be necessary to 

it all really depends on for what purpose.. for realtime processing 

moving matrices over ethernet seems to be a popular choice, but 

people have mixed results with resolution and frame rate, there are 

alot of 'ideal network' variables to consider. personally i prefer 

the high quality hardware approach. use a good, low latency video 

the Decklink Intensity card will let you move up to HD resolution 

video from one machine to another at very high quality. note though 

that the output resolution must be a legal broadcast signal, but the 

sending Mac should 'see' the Intensity card as legal automatically 

(with a DVI to HDMI adapter) the signal is uncompressed, 12 bit 

DFG-1394 - most popular for Jitter because of low cost - uses IIDC 

AJA IO - proprietary uncompressed firewire solution, SD resolution, 

10bit color (most costly of the 3, i would choose Intensity over this)

all of them surely do have 'some' latency, a couple frames or so.

jit.qt.video is a poor option - firewire dv is high latency, and it 

takes alot of cpu on both sides of the equation.

> On the other hand I am interested in the best way (especially with  
> the smallest latency) to get any video from one computer into  
> another. I'm a noob at this. Would it really be necessary to  
> convert to analogue and back, Johnny?

it all really depends on for what purpose.. for realtime processing  
it sounds like?

moving matrices over ethernet seems to be a popular choice, but  
people have mixed results with resolution and frame rate, there are  
alot of 'ideal network' variables to consider.  personally i prefer  
the high quality hardware approach.  use a good, low latency video  
digitizer.

the Decklink Intensity card will let you move up to HD resolution  
video from one machine to another at very high quality.  note though  
that the output resolution must be a legal broadcast signal, but the  
sending Mac should 'see' the Intensity card as legal automatically  
(with a DVI to HDMI adapter)  the signal is uncompressed, 12 bit  
color fidelity, but very high datarate.

DFG-1394 - most popular for Jitter because of low cost - uses IIDC  
uncompressed Firewire YUV color.

AJA IO - proprietary uncompressed firewire solution, SD resolution,  
10bit color (most costly of the 3, i would choose Intensity over this)

jit.qt.video is a poor option -  firewire dv is high latency, and it  
takes alot of cpu on both sides of the equation.

Thanks for the info. Time to give the DFG-1394 a try :)

Still wondering about the direct firewire to firewire approach though.

Quote: Johnny deKam wrote on Sat, 24 March 2007 22:07

> > On the other hand I am interested in the best way (especially with 

> > the smallest latency) to get any video from one computer into 

> > another. I'm a noob at this. Would it really be necessary to 

> > convert to analogue and back, Johnny?

> it all really depends on for what purpose.. for realtime processing 

> moving matrices over ethernet seems to be a popular choice, but 

> people have mixed results with resolution and frame rate, there are 

> alot of 'ideal network' variables to consider. personally i prefer 

> the high quality hardware approach. use a good, low latency video 

> the Decklink Intensity card will let you move up to HD resolution 

> video from one machine to another at very high quality. note though 

> that the output resolution must be a legal broadcast signal, but the 

> sending Mac should 'see' the Intensity card as legal automatically 

> (with a DVI to HDMI adapter) the signal is uncompressed, 12 bit 

> color fidelity, but very high datarate.

> DFG-1394 - most popular for Jitter because of low cost - uses IIDC 

> AJA IO - proprietary uncompressed firewire solution, SD resolution, 

> 10bit color (most costly of the 3, i would choose Intensity over this)

> all of them surely do have 'some' latency, a couple frames or so.

> jit.qt.video is a poor option - firewire dv is high latency, and it 

> takes alot of cpu on both sides of the equation.

Quote: Johnny deKam wrote on Sat, 24 March 2007 22:07
----------------------------------------------------
> > On the other hand I am interested in the best way (especially with  
> > the smallest latency) to get any video from one computer into  
> > another. I'm a noob at this. Would it really be necessary to  
> > convert to analogue and back, Johnny?
>
> it all really depends on for what purpose.. for realtime processing  
> it sounds like?
>
> moving matrices over ethernet seems to be a popular choice, but  
> people have mixed results with resolution and frame rate, there are  
> alot of 'ideal network' variables to consider.  personally i prefer  
> the high quality hardware approach.  use a good, low latency video  
> digitizer.
>
> the top three:
>
> the Decklink Intensity card will let you move up to HD resolution  
> video from one machine to another at very high quality.  note though  
> that the output resolution must be a legal broadcast signal, but the  
> sending Mac should 'see' the Intensity card as legal automatically  
> (with a DVI to HDMI adapter)  the signal is uncompressed, 12 bit  
> color fidelity, but very high datarate.
>
> DFG-1394 - most popular for Jitter because of low cost - uses IIDC  
> uncompressed Firewire YUV color.
>
> AJA IO - proprietary uncompressed firewire solution, SD resolution,  
> 10bit color (most costly of the 3, i would choose Intensity over this)
>
> all of them surely do have 'some' latency, a couple frames or so.
>
> jit.qt.video is a poor option -  firewire dv is high latency, and it  
> takes alot of cpu on both sides of the equation.
>
> -deKam
>
>
>
>
>
>
>
>
----------------------------------------------------


> video from one machine to another at very high quality. note 

> though that the output resolution must be a legal broadcast signal, 

> but the sending Mac should 'see' the Intensity card as legal 

> automatically (with a DVI to HDMI adapter) the signal is 

> uncompressed, 12 bit color fidelity, but very high datarate.

Did you actually try this yourself? The people from Decklink state 

the Intensity card won't work to record computer output DVI, due to 

differences in signal between HDMI and DVI (RGB/YUV and 50fps/60fps 

>
> the Decklink Intensity card will let you move up to HD resolution  
> video from one machine to another at very high quality.  note  
> though that the output resolution must be a legal broadcast signal,  
> but the sending Mac should 'see' the Intensity card as legal  
> automatically (with a DVI to HDMI adapter)  the signal is  
> uncompressed, 12 bit color fidelity, but very high datarate.
>

Did you actually try this yourself? The people from Decklink state  
the Intensity card won't work to record computer output DVI, due to  
differences in signal between HDMI and DVI (RGB/YUV and 50fps/60fps  
etc).

i'm still trying to figure out the best way to do my thing...:

someone told me that it is possible to use the firewire port like a second monitor on osx. that would be great, since i wouldn't need to get my openGL stuff back into jit.matrix. however, is that true (never heard of this before)? how would i use my FW port as a second monitor?

along a similar line of thought: i tried sending the video using jit.qt.videoout via firewire to another mac using jit.qt.grab. however that didn't work. none of the macs showed up as a device in ubumenu. so how would i do that?

I haven't actually tried it, this was based on my experience of being 

able to connect my macbook to an HD CRT television using a dvi->hdmi 

adapter (when doing so the mac enabled ATSC legal resolutions for 

1080i and 720p - i believe vade confirmed my findings(?) - if for 

some reason it didn't work, there is always going DVI to HD-SDI - 

>> the Decklink Intensity card will let you move up to HD resolution 

>> video from one machine to another at very high quality. note 

>> though that the output resolution must be a legal broadcast 

>> signal, but the sending Mac should 'see' the Intensity card as 

>> legal automatically (with a DVI to HDMI adapter) the signal is 

>> uncompressed, 12 bit color fidelity, but very high datarate.

> Did you actually try this yourself? The people from Decklink state 

> the Intensity card won't work to record computer output DVI, due to 

> differences in signal between HDMI and DVI (RGB/YUV and 50fps/60fps 

I haven't actually tried it, this was based on my experience of being  
able to connect my macbook to an HD CRT television using a dvi->hdmi  
adapter (when doing so the mac enabled ATSC legal resolutions for  
1080i and 720p - i believe vade confirmed my findings(?) - if for  
some reason it didn't work, there is always going DVI to HD-SDI -  
though this is much more expensive.

>>
>> the Decklink Intensity card will let you move up to HD resolution  
>> video from one machine to another at very high quality.  note  
>> though that the output resolution must be a legal broadcast  
>> signal, but the sending Mac should 'see' the Intensity card as  
>> legal automatically (with a DVI to HDMI adapter)  the signal is  
>> uncompressed, 12 bit color fidelity, but very high datarate.
>>
>
>
> Did you actually try this yourself? The people from Decklink state  
> the Intensity card won't work to record computer output DVI, due to  
> differences in signal between HDMI and DVI (RGB/YUV and 50fps/60fps  
> etc).
>
> Let me know,
> Best Lucas
>
>
>
>
>


On Mar 26, 2007, at 4:28 PM, dekam wrote:

> I haven't actually tried it, this was based on my experience of 

> being able to connect my macbook to an HD CRT television using a 

> dvi->hdmi adapter (when doing so the mac enabled ATSC legal 

> resolutions for 1080i and 720p - i believe vade confirmed my 

> findings(?) - if for some reason it didn't work, there is always 

> going DVI to HD-SDI - though this is much more expensive.

>>> the Decklink Intensity card will let you move up to HD resolution 

>>> video from one machine to another at very high quality. note 

>>> though that the output resolution must be a legal broadcast 

>>> signal, but the sending Mac should 'see' the Intensity card as 

>>> legal automatically (with a DVI to HDMI adapter) the signal is 

>>> uncompressed, 12 bit color fidelity, but very high datarate.

>> Did you actually try this yourself? The people from Decklink state 

>> the Intensity card won't work to record computer output DVI, due 

>> to differences in signal between HDMI and DVI (RGB/YUV and 50fps/ 

>
> I haven't actually tried it, this was based on my experience of  
> being able to connect my macbook to an HD CRT television using a  
> dvi->hdmi adapter (when doing so the mac enabled ATSC legal  
> resolutions for 1080i and 720p - i believe vade confirmed my  
> findings(?) - if for some reason it didn't work, there is always  
> going DVI to HD-SDI - though this is much more expensive.
>
> --jdk
>
>
>
>
>
>
>>>
>>> the Decklink Intensity card will let you move up to HD resolution  
>>> video from one machine to another at very high quality.  note  
>>> though that the output resolution must be a legal broadcast  
>>> signal, but the sending Mac should 'see' the Intensity card as  
>>> legal automatically (with a DVI to HDMI adapter)  the signal is  
>>> uncompressed, 12 bit color fidelity, but very high datarate.
>>>
>>
>>
>> Did you actually try this yourself? The people from Decklink state  
>> the Intensity card won't work to record computer output DVI, due  
>> to differences in signal between HDMI and DVI (RGB/YUV and 50fps/ 
>> 60fps etc).
>>
>> Let me know,
>> Best Lucas
>>
>>
>>
>>
>>
>


Quote: robin.meier wrote on Mon, 26 March 2007 14:43

> along a similar line of thought: i tried sending the video using jit.qt.videoout via firewire to another mac using jit.qt.grab. however that didn't work. none of the macs showed up as a device in ubumenu. so how would i do that?

hey, that was my question! ;) (see earlier in this thread)

Quote: robin.meier wrote on Mon, 26 March 2007 14:43
----------------------------------------------------
> along a similar line of thought: i tried sending the video using jit.qt.videoout via firewire to another mac using jit.qt.grab. however that didn't work. none of the macs showed up as a device in ubumenu. so how would i do that?

We just got our intensity cards, and are having some odd issues with 

both of them. So I cannot confirm that it works 100% at this time. We 

are able to get image input via DVI out from a Macbook to a Mac Pro 

via DVI -> HDMI adaptor, but have really weird color issues. Its not 

just jitter, but FCP as well. I havent spoken to blackmagic but will 

take a look at it once I get back to NYC in a few days personally :)

(wow that makes me sound all important and shit :)

Ill let the list know how things go once I get my hands on it myself.

On Mar 26, 2007, at 5:36 PM, subzero wrote:

> On Mar 26, 2007, at 4:28 PM, dekam wrote:

>> I haven't actually tried it, this was based on my experience of 

>> being able to connect my macbook to an HD CRT television using a 

>> dvi->hdmi adapter (when doing so the mac enabled ATSC legal 

>> resolutions for 1080i and 720p - i believe vade confirmed my 

>> findings(?) - if for some reason it didn't work, there is always 

>> going DVI to HD-SDI - though this is much more expensive.

>>>> the Decklink Intensity card will let you move up to HD 

>>>> resolution video from one machine to another at very high 

>>>> quality. note though that the output resolution must be a legal 

>>>> broadcast signal, but the sending Mac should 'see' the Intensity 

>>>> card as legal automatically (with a DVI to HDMI adapter) the 

>>>> signal is uncompressed, 12 bit color fidelity, but very high 

>>> Did you actually try this yourself? The people from Decklink 

>>> state the Intensity card won't work to record computer output 

>>> DVI, due to differences in signal between HDMI and DVI (RGB/YUV 

We just got our intensity cards, and are having some odd issues with  
both of them. So I cannot confirm that it works 100% at this time. We  
are able to get image input via DVI out from a Macbook to a Mac Pro  
via DVI -> HDMI adaptor, but have really weird color issues. Its not  
just jitter, but FCP as well. I havent spoken to blackmagic but will  
take a look at it once I get back to NYC in a few days personally :)

> Vade, can you confirm this?
> Best Lucas
>
> On Mar 26, 2007, at 4:28 PM, dekam wrote:
>
>>
>> I haven't actually tried it, this was based on my experience of  
>> being able to connect my macbook to an HD CRT television using a  
>> dvi->hdmi adapter (when doing so the mac enabled ATSC legal  
>> resolutions for 1080i and 720p - i believe vade confirmed my  
>> findings(?) - if for some reason it didn't work, there is always  
>> going DVI to HD-SDI - though this is much more expensive.
>>
>> --jdk
>>
>>
>>
>>
>>
>>
>>>>
>>>> the Decklink Intensity card will let you move up to HD  
>>>> resolution video from one machine to another at very high  
>>>> quality.  note though that the output resolution must be a legal  
>>>> broadcast signal, but the sending Mac should 'see' the Intensity  
>>>> card as legal automatically (with a DVI to HDMI adapter)  the  
>>>> signal is uncompressed, 12 bit color fidelity, but very high  
>>>> datarate.
>>>>
>>>
>>>
>>> Did you actually try this yourself? The people from Decklink  
>>> state the Intensity card won't work to record computer output  
>>> DVI, due to differences in signal between HDMI and DVI (RGB/YUV  
>>> and 50fps/60fps etc).
>>>
>>> Let me know,
>>> Best Lucas
>>>
>>>
>>>
>>>
>>>
>>
>

I should note that I emailed decklink to ask about the colorspace 

issue and they stated it should work (at least the email drone who 

replied to me did). I asked my co-worker to try some colorspace 

conversion objects within jitter, but what is odd is that the cards 

are showing issues in FCP, on Air and in Jitter, so I dont know if 

its some weird problem with both cards, or if this wont work. Either 

> We just got our intensity cards, and are having some odd issues 

> with both of them. So I cannot confirm that it works 100% at this 

> time. We are able to get image input via DVI out from a Macbook to 

> a Mac Pro via DVI -> HDMI adaptor, but have really weird color 

> issues. Its not just jitter, but FCP as well. I havent spoken to 

> blackmagic but will take a look at it once I get back to NYC in a 

> (wow that makes me sound all important and shit :)

> Ill let the list know how things go once I get my hands on it myself.

> On Mar 26, 2007, at 5:36 PM, subzero wrote:

>> On Mar 26, 2007, at 4:28 PM, dekam wrote:

>>> I haven't actually tried it, this was based on my experience of 

>>> being able to connect my macbook to an HD CRT television using a 

>>> dvi->hdmi adapter (when doing so the mac enabled ATSC legal 

>>> resolutions for 1080i and 720p - i believe vade confirmed my 

>>> findings(?) - if for some reason it didn't work, there is always 

>>> going DVI to HD-SDI - though this is much more expensive.

>>>>> the Decklink Intensity card will let you move up to HD 

>>>>> resolution video from one machine to another at very high 

>>>>> quality. note though that the output resolution must be a 

>>>>> legal broadcast signal, but the sending Mac should 'see' the 

>>>>> Intensity card as legal automatically (with a DVI to HDMI 

>>>>> adapter) the signal is uncompressed, 12 bit color fidelity, 

>>>> Did you actually try this yourself? The people from Decklink 

>>>> state the Intensity card won't work to record computer output 

>>>> DVI, due to differences in signal between HDMI and DVI (RGB/YUV 

I should note that I emailed decklink to ask about the colorspace  
issue and they stated it should work (at least the email drone who  
replied to me did). I asked my co-worker to try some colorspace  
conversion objects within jitter, but what is odd is that the cards  
are showing issues in FCP, on Air and in Jitter, so I dont know if  
its some weird problem with both cards, or if this wont work. Either  
way I will report back asap :)

> We just got our intensity cards, and are having some odd issues  
> with both of them. So I cannot confirm that it works 100% at this  
> time. We are able to get image input via DVI out from a Macbook to  
> a Mac Pro via DVI -> HDMI adaptor, but have really weird color  
> issues. Its not just jitter, but FCP as well. I havent spoken to  
> blackmagic but will take a look at it once I get back to NYC in a  
> few days personally :)
>
> (wow that makes me sound all important and shit :)
>
> Ill let the list know how things go once I get my hands on it myself.
>
> On Mar 26, 2007, at 5:36 PM, subzero wrote:
>
>> Vade, can you confirm this?
>> Best Lucas
>>
>> On Mar 26, 2007, at 4:28 PM, dekam wrote:
>>
>>>
>>> I haven't actually tried it, this was based on my experience of  
>>> being able to connect my macbook to an HD CRT television using a  
>>> dvi->hdmi adapter (when doing so the mac enabled ATSC legal  
>>> resolutions for 1080i and 720p - i believe vade confirmed my  
>>> findings(?) - if for some reason it didn't work, there is always  
>>> going DVI to HD-SDI - though this is much more expensive.
>>>
>>> --jdk
>>>
>>>
>>>
>>>
>>>
>>>
>>>>>
>>>>> the Decklink Intensity card will let you move up to HD  
>>>>> resolution video from one machine to another at very high  
>>>>> quality.  note though that the output resolution must be a  
>>>>> legal broadcast signal, but the sending Mac should 'see' the  
>>>>> Intensity card as legal automatically (with a DVI to HDMI  
>>>>> adapter)  the signal is uncompressed, 12 bit color fidelity,  
>>>>> but very high datarate.
>>>>>
>>>>
>>>>
>>>> Did you actually try this yourself? The people from Decklink  
>>>> state the Intensity card won't work to record computer output  
>>>> DVI, due to differences in signal between HDMI and DVI (RGB/YUV  
>>>> and 50fps/60fps etc).
>>>>
>>>> Let me know,
>>>> Best Lucas
>>>>
>>>>
>>>>
>>>>
>>>>
>>>
>>
>
> v a d e //
>
> www.vade.info
> abstrakt.vade.info
>
>
>

Hello Vade, this sounds as expected. This is what Dan May 

(Blackmagic), states about using the Intensity card for recording a 

Q. Can I convert DVI to HDMI with a converter (similar to the bender 

that comes with HDLink/Multibridge Extreme) and capture that HDMI 

A. UNLIKELY- as Intensity cards are looking for YUV video and 

supported television frame rates and resolution.

This request generally comes from folks looking to take the DVI 

output of their computer and convert it to HDMI to be captured as 

video. The problem here is that while DVI and YUV share a similar pin 

video out / in for mac's