Quicktime 7.6.4 and video displaying as a white frame.

[Fergus Mount]

Hi all, 

I have had an interesting few days trying to to get 2.3.7 to work on an intel Mac Pro with 10.5.8. We have a ATI Radeon 4870 installed with 512MB Vram.  

The mac was running the show on 2.3 and I wanted to update it to Qlab 2.3.7, but when I ran some of the video in the show in 2.3.7 they just came up as white frames. 

I did a bit of investigation and quicktime on the mac pro was an old version, 7.6.4 so I decided to update quicktime to 7.7. Software update did not recognise that the version of quicktime was so out of date so I had to manually update it.  Now the video files all play in 2.3.7, but there is one video where the first few frames are completely white. This only happens in 2.3.7, when I run it in 2.3 there are no white frames.  The video is rendered in photo JPEG and I have tried to transcode the video to prores 422 and the same problem exists. Even when I create a new workspace and have that video as the only cue the white frames appear. 

There are no messages in the console that correlate to that specific video cue. 

 

I can still go back and use Qlab 2.3, but I would rather have it up to date.

Any ideas would be much appreciated! 

Fergus 

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[Fergus Mount]

Oh and I should have mentioned that I run my laptop as a show backup, and it does not happen on that. I am running Lion with Qlab 2.3.7 on a 2011 MBP 

[Chris Ashworth]

Hi Fergus,

I don't off the top of my head know what would cause this.

I wonder if there are other unique things related to this cue, since it happens with different encodings. For example, is a lot of video being loaded around the time that cue fires? Is the resolution higher than the other cues?

-C

[Keith Smith]

On 23 May 2012, at 10:47, Fergus Mount wrote:

> Now the video files all play in 2.3.7, but there is one video where the first few frames are completely white. This only happens in 2.3.7, when I run it in 2.3 there are no white frames. The video is rendered in photo JPEG and I have tried to transcode the video to prores 422 and the same problem exists. Even when I create a new workspace and have that video as the only cue the white frames appear.

I think you are dropping the first few frames - what is your background set to, it's not white by any chance?

_If_ you are dropping frames I'd guess that you have a cue(s) that are being loaded while this video is starting to play (and I'd guess that it is also a video cue) and it is stealing time and disk from you. Try using the Load cue to load the cues after this video cue at some earlier point in workspace.

FWIW I have gotten into the habit of using Load cues on _all_ my video cues because it is the only way I can guarantee the load will take place at a time that won't interfere with anything, no matter what machine I might move the show to. A Load right after stills are particularly good.


K.

[Fergus Mount]

Hi Chris and Keith, 

Thanks fort the replies. 

I think you are dropping the first few frames - what is your background set to, it's not white by any chance?

 

It is set to black :-) 

I wonder if there are other unique things related to this cue, since it happens with different encodings. For example, is a lot of video being loaded around the time that cue fires?  Is the resolution higher than the other cues?

-C

 

I had thought it might be a loading problem, but I created a new workspace and a new video cue and made sure that it was loaded and the white frames still appeared. I don't think it is a bottleneck issue, as surely it would then be a problem in both versions of Qlab. 

Most of the content for the show is 1024x768, but the video in question is 1920x740.  The projector is running at 1600x1200, so I could try scaling it to the same width.  

I suspect it is a system issue, as it is an old system that has been through the hands of many operators programmers so it might need a bit of TLC! I plan to install 10.6.8 on a new disk and start testing it on that and I imagine once everything is up to date the problem will disappear.

Thanks 

Fergus 

[Chris Ashworth]

Hi Fergus,

Try lowering the resolution of the video - when a card can't handle the resolution of a video or image it often results in a white frame. I'm not sure why that would happen for the first frame(s) and not the whole video, but it sounds like this could be the culprit.

-C

[Fergus Mount]

Thanks Chris, 

I will give that a go when I am back on the road next week. I installed a fresh copy of OSX 10.6.8 on a new hard drive and tested it on Qlab 2.3.7 and I didn't have any problems at all, so it looks like a funny system problem might well have been the cause.  

Cheers for the help! 

Fergus