Maximum media file width

[mitreklov]

We are testing solutions for an up coming project that requires the replay of 30000 (Thirty thousand) pixel wide by 850 pixel high 50fps media files.

 

Our initial approach was to use multiple WO displays, pre split the movies and let each display deal with smaller sections. However after extensive testing and despite using frame locked GPUs across all chassis we were unable to achieve 100% synchronous playback on every pass. It worked 90% of the time and less than 50% without the sync card enabled.  As the final display is a continuous LED screen where the 16 HD outputs will be butt joined, the smallest timing errors become very noticeable.

 

Plan B is to build a machine powerful enough machine to replay a single file at 30000 pixels wide, the pros and cons of that build I won't go into here but initial tests with media files of that size suggest there is an upper limit on the file width size that WO will accept. We have created files at this size using various codecs that will support that pixel count however any file wider than what looks like 16000 pixels returns a "Your hardware will not support that file size" message. So I'm trying to work out if this a WO imposed limit or the message is generated by the Windows environment or the GPU driver.

We have successfully tested playback of 2 x 15000px wide movies with 100% sync success so clearly the hardware is up to pushing that number of pixels, so where is the limitation on the file size pixel width?

 

Any guidance from those in the know would be helpful.

 

If we get it work it will be a monster!!

 

Thanks

 

[Miro]

Hi, there is a texture size limit for DirectX9 on the GPU which normally is 16K x 16K. It's much smarter to rearrange your LED tiles from 30'000x850 on an area corresponding to 4x UHD 4K monitors like 7680x4320. The media will probably be more coding efficient also.

 

WATCHOUT uses frame sync but not swap sync/barrier so if the computers in the cluster are too slow they might miss a v-sync interval every now and then. One computer could drop a frame which will cause tearing if it's neighbors doesn't drop the same frame.

[mitreklov]

Thanks for the reply, that makes perfect sense. We'll look at optimising and rearranging things within the 16k texture box limit.