HD Thunder dropping frames on HDMI output

[mrmidi]

I am playing DVCPro HD clips (1080i 59.94) in EDIUS V5 using the HD Thunder hardware. I am monitoring the output using the HD Thunder HDMI output connection.

When I watch the video playback on an HDMI monitor - I see that HD Thunder HDMI output is dropping frames on playback. It drops approx. 1 or 2 frames every 3-4 seconds.

This is very annoying to look at - and really not acceptable.

I also see that the HD Spark is having the exact same problem - on a totally different PC. So - this tells me there is a low level issue in the HDMI hardware - or at least that the HDMI output is having problems playing DVCPro HD 100.

I am surprised that no one else has mentioned this on the forums. (or at least I have not seen any mention of this issue on the forum).

[SRsupport]

I Just dropped a dvcpro HD1080/60i on a timeline outputting via the Hdstorm HDMI.

I see no problems here.

[johannesj]

Same here, no problems on HD1080/60i on a timeline and HDMI output.

[johannesj]

Sorry, this was not a HD1080 60i file.

Sorry

[Zorro]

Have you set Edius to continue to play back the timeline when a frame drop occurs? The card is a wysiwyg thing so I think that you have a playback problem related to a slow harddisk.

[mrmidi]

HD Thunder HDMI Output

Okay - sorry but perhaps this was a false alarm on my part.

Here's what I found out with further experimentation.

. . . The Acer 24" LCD monitor w/ HDMI input seems to have an issue with dropping frames. . . not really sure if the HD Thunder card is causing this or not. . . .hopefully not.

I connected to a Sharp 42" LCD and the problem does not show up there - looks great. So I was very happy to see the Thunder HDMI output working right.

All HD resolutions are playing properly when connected to the Sharp 42" LCD via HDMI. All 720x480 resolutions also work well on the Sharp 42" and it can handle 4x3 and 16x9.

The Project settings that I used for tests were [email protected] (DVCProHD) and [email protected] (Full HD) Canopus HQ AVI 1920x1080 coming from Digital Juice Juicer - outputting HD animations.

So now I know that a standard HD TV type monitor works properly w/ HDMI output from the HD Thunder.

A word to the wise - invest in a proper HDTV type display - as the Thunder seems to work good when paired up that way - and apparently not so well on computer monitors w/ HDMI inputs.

I have now tested HD Thunder's and HD Spark's HDMI output using 2 different 24" Acer models and 1 Samsung 24" - Acers are dropping frames but do accept a 4X3 720x480 resolution while Samsung 24" plays HD without issues - but refuses to recognize the 4x3 720x480 NTSC DV - unless I make it 16x9 - at which point it will work (display video via HDMI) using 720x480 NTSC DV.

Hard drive I/O speed does not appear to be a factor on this one.

Thanks to all for your replies.

[mrmidi]

HD Thunder and HDMI Output

I should also mention - for the record - that the same Acer 24" LCD monitor that drops frames when used with HD Thunder's HDMI, has no problems when watching a Blu Ray movie via HDMI.

[GrassValley_BH]

What's the native refresh rate of that Acer LCD monitor? You might be seeing judder and not an actual frame drop.

[mrmidi]

Refresh Rate

The monitor supports vertical refresh rates between 55 and 75Hz

It is a fairly expensive monitor ($400.00) and it has a 50,000:1 contrast ratio.

It's called the Acer G24 Monitor. It has a 2ms response time.

The same problem occurs on the Acer P243 - which is also 24" LCD.

At this point - I would venture to guess that the issue I am seeing is due to an improper HDMI handshake between the Acer 24" monitor (which supports HDMI V 1.3 w/ HDCP) and the HD Thunder's HDMI output connector which is HDMI V1.1 and does not support HDCP handshaking.

When there is no handshake the monitor will either drop to displaying a lower pixel count resulting in a blurry image at half the typical HD resolution - or it will just drop frames every second or two - resulting in an unusable video image.

[GrassValley_BH]

The monitor supports vertical refresh rates between 55 and 75Hz

That's kind of the root of the problem...

What the monitor supports input-wise, is different from what the monitor itself has to address digitally.

Wasn't a problem in the analog days, because there weren't individual pixels that were either on or off.

But in digital displays, the number of pixels is fixed so the display has to apply processing to determine whether a given pixel is on or off. So is the panel refresh rate, regardless of whether it's refreshing the exact same image or differing images.

That processing is where issues can arise.

Since you're seeing it on two different Acer models, I wonder if it could be an artifact of the scaling/deinterlacing algorithm the Acer displays use.
You could also be correct that there's a handshaking error in the HDMI, however, HDMI spec dictates that the handshake between the two should occur at HDMI v1.1, as that's the highest common standard between the two, so the version mismatch shouldn't be a problem.

HDTHUNDER is the source and it doesn't use HDCP, so the monitor should accept it fine.