This post was last modified: 2022-08-14, 10:32 by Gunther.

Visual Previews will be generated in many parallel threads. If the generation of each preview doesn't succeed after 30 seconds, it will time out. After 3 failed tries, the VP indicator below the preview will turn red and preview generation will fail.
There might be different reasons, why this happens:
1.) Some virus scanner or security setting on your computer might stall the communication between LRTimelapse and the Adobe DNG Converter which will be used for preview generation
2.) The images cannot be loaded or processed fast enought, this might happen because of a slow harddrive or network drive for example.

To troubleshoot the issue:

• Make sure to have installed the latest version of Adobe DNG Converter: https://lrtimelapse.com/install/
  
• Make sure nothing is blocking on your computer. Whitelist LRTimelapse and Adobe DNG Converter in your virus scanner
  
• On Windows: make sure you have not more than one virus scanner running. Usually the built in Windows Defender is the best and fastest option anyway. Put the folder C:\Program Files\LRTimelapse 6 in the white list of the scanner.
  
• On mac: allow full disc access, to prevent the OS from blocking any access, see: https://forum.lrtimelapse.com/Thread-wil...-and-later
  
• Make sure your timelapse sequences are located on a fast drive (an internal ssd would be best). External harddrives might be too slow, the same goes for regular network storage. I'd recommend at least 5Gbit Ethernet connection and a NAS that is fast enough, if you want to work directly on a network drive.
  
• If all of this doesn't help, reduce the number of parallel threads for Visual Preview generation in LRTimelapse's settings/Expert settings. Set it to half the value and see if that helps. You can experiment with the value and see which one will get you consistent results. If this is the issue, you might also need to reduce the other setting for number of parallel threads for internal export.
  

The bigger your raw files, the more processing power you will need, the faster your drives must be able to deliver the images.
Also: the more parallel threads you use, the faster your drives must be able to deliver the images.

The bigger your raw files, the more processing power you will need, the faster your drives must be able to deliver the images.

Do you use the real RAW data or just the preview images?
I have had very good experiences with reading only part of the RAW data. If you only take every tenth pixel, it is almost no different from the result than if you take all pixels.

Visual previews are developed raw files. It's not just raw data, all the edits are being applied. This happens via the DNG Converter. From my experience larger raw files take more time tja smaller ones. Nikon and Canon files are faster to process than Fuji and even Sony.

Sent mobile...

Another thing to verify is that you have no corrupted files which can also trigger timeout from DNG converter.

Another thing to verify is that you have no corrupted files which can also trigger timeout from DNG converter.

Hello,
the link in Gunther's first post is dead, but the process to allow full disk access via Mac OS System Preferences is quite easy. My question is : if you don't have issues generating VP, is it helpful to allow full disk access? Will this speed up the process of generating VP?

I have tried all of the tips suggested in this thread. I am on a Mac running Big Sur. I have given full disk access to LRT time-lapse and to Adobe DNG Converter. I have given the appropriate number of threads to LRT time-lapse. All my drives are very fast SSD drives. I've tried only internal drive or fast outboard thunderbolt drives and still I cannot get previews.

I am shooting with a Sony A1 camera and the image resolution is 8704x6144 in the uncompressed lossless format. I do not have any issues with these files in any other application I use but for some reason LRT Time-lapse will not give me visual previews to check my output and make sure my transitions are good. I am better off just loading these in Lightroom as I can get a near real time preview at full quality.

Jack Tunnicliffe
Java Post Production

I've tested my issue with Sony A1 compressed lossless and here's some further information for how I work around the issue of these files not creating visual previews in LRT time-lapse. Once I reimport my files from Lightroom, I select auto transition to get the keyframe changes that LRT does so well. I know I'm not going to get my visual previews so I save and reimport my metadata in Lightroom. Unfortunately I get frames in Lightroom that will not view properly and there is now a yield sign on the icon in Lightroom and it says that Lightroom can't read this file. I've tried copying and pasting data from an adjacent frame but this won't work so I got to the folder with my raw files, duplicate the xmp file for the adjacent frame in an outside folder and rename it with the number of the frame with the yield sign and replace that xmp file and now everything is fine. This is a heck of a tough workaround but the only way I've been able to continue to use LRT with these files. I'd be interested if other Sony A1 users are having issues.

I'm able to process Nikon D4 and Sony A7SIII files fine so I don't think it is an antivirus blockage setting (correct me if I'm wrong). For the A1 uncompressed RAW the files are 102,535KB. I'm using a 12 core RYZEN, SSD, 64GB ram. Visual previews choke when 97% complete. I noticed that every 24th frame is yellow and stuck in processing (there is a yellow tick every 24th frame on the red bar at the bottom.) I reduced the cores to 12 in the settings but it doesn't change anything. I could understand that processing would take longer with larger files but I find it strange that processing crawls to a complete stop eventually. I will give compressed raw a whirl and see what happens.

Do you have installed a version of the Adobe Dng Converter that supports that camera?

Also id try to keep the raw file sizes smaller by using compressed raw. It won't sacrifice quality. If that doesn't help, increase the timeout time in the expert settings a bit.

Sent mobile...