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Content for very large LED wall not syncing

S400 Sync H264 MP4 LED 1920 by 1200

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#1 Playground

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Posted 15 January 2017 - 04:52 PM

Hello

 

I am having trouble getting 4 MP4 video files to sync on a very large LED wall.

The files are built at 50 fps because some of the content in side the content is european. 

We have Show Sage Built watch rack computers with the s400 sync card installed and working.

All 4 files are coming off 1 machine with 4 heads.

 

We are Emulating a 1920 by 1200 EDID at 50 hz. Watchout is connected to a Light ware 8X8 DVI router than fed DVI to 4 Image pros2 then fed to the LED Brain

 

 

We have tried setting watchout to 75 fps and also custom at 50fps with no luck.

 

I feel it is the H264 codec but would like to confirm or deny this.

We have asked the agency to send us Pro res files to compare.

Would HAP be a better choice?

 

B Chaisson

Playground Studios

 

 



#2 mindopera

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Posted 15 January 2017 - 08:08 PM

I have been using HAPQ files for about 8 months and love the result. It may be worth doing a test set of files to see if the results are better. HAPQ files use the GPU more directly, as opposed to MP4 files which use the CPU more. Also don't split the HAPQ files. Leave it as one file that fits accross the entire video canvas, such as 7680x1080. Give that a try also.

Most video walls have a native resolution. Do you know what that is for the wall your working on.
Are there video procecors in between your video signal and the video wall? What resolution are they sending to the wall?

It could be the extra processing in between that is causing the sync issue.
Call me if you want to talk. I'm in Seattle WA.
Hope that helps.

#3 Myngus

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Posted 16 January 2017 - 02:54 AM

have you set output one as your timing master, and then outputs 2, 3 and 4 as timing clients?



#4 akipfer

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Posted 17 January 2017 - 06:25 PM

In this same vein, we're outputting 5 heads from 1 ShowSage ShowServer HXD (WO6) machine and having trouble with staggered starts on the outputs as well.  I think it's CPU and codec related because after a few loops of the timeline, WO crashes.  I've gotten them running smoothly as single file loops for each output by disabling b-frames (still H.264), but when I try to run multiple smaller files (for pixel mapping) within the same timeline, I run into the staggering on loop (and crashes).

 

Do you think that HAPQ would help?

 

Also, what would be the easiest route for having the client convert to HAPQ on a Mac.  They are producing in Adobe AfterEffects and/or Premiere.  Trying to shorten the workflow as possible if it comes to HAPQ running smoother.



#5 akipfer

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Posted 17 January 2017 - 09:21 PM

Actually, some quick googling answered the last questions about workflow.  I've converted a test to HAPQ and it definitely makes for a larger file, but I haven't tested it on the playback sync yet.



#6 Miro

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Posted 19 January 2017 - 09:00 PM

When running the h.264 files did you monitor the CPU usage to see if it peaks? When the h.264 videos are starting to drop frames then sync between the videos will fail.

 

We updated the h.264 codecs in 6.1.5 with better memory handling. You could try re-building the show cache and test the new version to see if it helps. Another option is to use MPEG-2 which consumes less resources in decoding then h.264.

 

If your storage can handle the HAPQ bandwidth then it's probably the preferred solution running a single file. Just make sure you encode it with chunks to take advantage of multiple threads in the decoding.







Also tagged with one or more of these keywords: S400, Sync, H264, MP4, LED, 1920 by 1200