Level 1

141 points

How to send HMDI video to 23" Cinema HD Display?

Need to figure out a way to play files from my Canon HD video camera while viewing same on my 23" Cinema HD Display.

Won't go into the shaggy dog reasons why, but this has to be from the camera itself, NOT after first transferring the files onto the hard drive of the computer to which the Display is normally connected (via DVI).

The camera can output video via HDMI, or via a cable that converts the video to an analog yellow/red/white composite signal. Ideally would just like to essentially create an HDMI video input option for the display (a now standard option on many low-end monitors). But have already learned that a simple HDMI-to-DVI cable adapter from Monoprice isn't enough in this case -- something re single- vs. dual-link compatibility?

So any suggestions greatly appreciated on how get one of these Cinema Displays to display video from an HDMI source (or failing that, from an analog composite video signal -- though I'd obviously prefer to keep the video flow all-digital).

Thanks!

John B.

Toronto

Mac Pro, 8-core 2.8GHz; 10 GB; GeForce 8800, Mac OS X (10.6.8), Mac user since 1990 (starting on a sleek SE/30)

Posted on Nov 17, 2011 11:42 AM

22 replies

John Bertram Author

Level 1

141 points

Dec 29, 2011 12:56 PM in response to samberl

samberl wrote:

The ACD does not have a HDMI in.

I definitely get that part.

samberl wrote:

The Apple 23" ACD only requires a Single-Link DVI input not a Dual-Link, that is required only for the 30" ACD.

Interesting -- but then why do I keep getting that blank screen when I connect a DVI-D signal to the 23" display via a Single Link connector?

samberl wrote:

HDMI out requires HDMI in, its as simple as that.

So does this mean that while I can always convert DVI (or MiniDVI) to HDMI, or DisplayPort (or MiniDP) to HDMI, an HDMI signal itself cannot be converted to a DVI signal of any kind (at least not via a simple adapter connection, as when converting to HDMI) -- despite what the vendors' sale descriptions claim?

samberl

Level 4

2,007 points

Dec 29, 2011 3:32 PM in response to John Bertram

Quote from DVI wikipedia

"An HDMI source differentiates between a legacy DVI display and an HDMI-capable display by reading the display's EDID block."

and

"To promote interoperability between DVI and HDMI devices, both HDMI source components and HDMI displays are required to support DVI signalling."

and there's more, if you have the time and interest to read the wiki.

It appears the problem is that the Canon HDMI is not recognising the 23" Apple ACD.

You are trying to marry old tech with new tech, and old tech doesn't know about the new tech.

John Bertram Author

Level 1

141 points

Dec 29, 2011 8:29 PM in response to samberl

Thanks for the link to the first article I've seen that seems to tackle this specific issue head on. And interestingly -- the sections you just quoted notwithstanding -- it also seems to offer a ray of hope just a few lines later:

"Absent this HDCP issue, an HDMI-source and DVI-D display would enjoy the same level of basic interoperability."

It uses the example of a Blu-Ray player as an instance where this HDCP copy protection could be a limiting factor -- which makes me think this would not likely apply to an acquisition-only device like an AVCHD camcorder.

Of course the relevant section then concludes with the usual "ultimately depends on the indivdual devices", "your mileage may vary" caveats -- but now I'm thinking maybe I should justr risk a few dollars and test out a couple of these adapter cables specifically labelled "HDMI to DVI-D", and whose DVI connector is definitely in the Dual Link configuration (according to the DVI connector diagrams).

Unless (even though I can't imagine why) the camcorder DOES employ the HDCP copy protection protocol, in which case this may indeed be example of new tech (the camera) vs. old tech (the presumably HDCP-unaware Cinema Display). Which would be ironic, since they were both purchased around the very same time (mid 2008).

Interesting.

Jan 2, 2012 4:49 PM in response to John Bertram

The problem is not the connection. The Apple display uses single-link DVI which is compatible with HDMI via adapters. The problem is resolution. The display is expecting 1920 x 1200 60 Hz progressive scan. Normal HDMI video is never greater than 1920 x 1080. I have seen some reports of 1080p working, but it is not a supported resolution for the display, and would not fill the screen.

May 14, 2012 8:08 AM in response to John Bertram

Did you ever find a solution, to this issue? I am currently trying to attatch the 23" ACD directly to a couple cameras, and am not getting a signa. I did purchase one of the cheap DVI>HDMI connectors from MonoPrice, but am not seeing anything.

Did you achieve connection, and if so, what did you use.

And if you did not achieve connection, and think you have thoroughly exhausted options, PLEASE lmk.

Thanks.

John Bertram Author

Level 1

141 points

May 14, 2012 9:01 AM in response to AdamAndroid

Thanks for the reminder -- as I neglected to update this thread.

A couple of months back, I did in fact do what I described in an earlier post, i.e...

risk a few dollars and test out a couple of these adapter cables specifically labeled "HDMI to DVI-D", and whose DVI connector is definitely in the Dual Link configuration (according to the DVI connector diagrams).

Sadly, the end result was always the same: a blank screen. I could go from the HDMI out of my camera to the DVI in of a third party, 1920x1080 monitor no problem. But with my 23" Apple Cinema HD display, nothing. So perhaps the stumbling block is indeed the different resolution, as Malcolm describes above (though on that point, I was naively hoping to just see some black-bar letterboxing to compensate for the missing 120 vertical pixels).

In any case, having now tried all the permutations and combinations I can think to try (and paying the restocking fee after returning the cables), I'm forced to conclude that the only economical way to do what I'd like to be able to do is to not do it -- and just get a separate monitor dedicated to that purpose. Which in my particular and space-challenged setup would be physically awkward to include.

Sad to say, in the world of format abbreviations, it looks like playing camera AVCHD files via HDMI Out directly to DVI In on an ACHD display = SOL.

:-(

May 14, 2012 2:29 PM in response to John Bertram

risk a few dollars and test out a couple of these adapter cables specifically labeled "HDMI to DVI-D", and whose DVI connector is definitely in the Dual Link configuration (according to the DVI connector diagrams).

The adapter is really single-link. Dual-link DVI connectors are sometimes used for single-link applications, but the extra pins are not connected. It may be just a matter of not having to stock so many different connectors, or it may be to allow the use of dual-link DVI extension cables, which also work for single-link but cannot plug into a single-link socket.

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How to send HMDI video to 23" Cinema HD Display?