Scene Detect Slows Down After +30 Minutes

NormRidg

Newbie Joined: Mar 17, 2013 00:38 Messages: 5 Offline

Solved by

Dec 27, 2020 09:33

I have a 2 hour video I transfer from VHS to digital. The converted video was MPG format. I wanted PD 365 to scene detect. There are bad places in the video (tape degrading) so scene detection would also segement these out as well. It flew through it well for the first 30 minutes of the video, but then sound of the video playing came on and the scan rate dropped to real time as the sound played.

Is PD limited to about 30 minutes of video for scene detection before it runs out of resources and then drops out to real time scanning? I chopped it up to 30 minute intervals (MP4) and worked fine.

Would it worked better if it was MP4?

Also, I would like to add. The creation of subfolder with the segments contained within is great to use. This was perfect if it just would process the entire file at the speed it did during the first 30 minutes.

This message was edited 1 time. Last update was at Dec 27. 2020 09:35

optodata

Senior Contributor Location: California, USA Joined: Sep 16, 2011 16:04 Messages: 8630 Offline

Dec 28, 2020 17:18

I'm glad your workaround of cutting the clip into smaller sections worked out, but I'm not clear on why you'd have an issue after 30 minutes. There's nothing about the file type that I can think of that might play any role.

I just tried an mpg clip with a duration of 1h 26m, and PD detected 309 scenes after running for about 5 minutes:

I'm wondering if maybe your PC was low on RAM or disk space which caused PD to suffer a kind of crash that broke the scene detection tool and basically just started playing the video with sound.

Please follow the steps listed in the Read Me Before Posting guide and provide the dxDiag report. Also please include the exact version of PD.

Another possibility - especially if the Scene Detection sensitivity was set too high - is that maybe you reached a number of scenes that cuased something in PD to overflow. Were there more than, say, 500 scenes in the first 30 minutes?

NormRidg

Newbie Joined: Mar 17, 2013 00:38 Messages: 5 Offline

Dec 29, 2020 11:31

The PC has 12 GB of ram and 250 GB of free hard disk. The file is 6.5 GB and converting it to MP4 using PD reduced it to 5.8 GB. I don't see a resource limitation. The MP4 version worked correct with no issues. Had about 600 total screens which I stripped out +100 bad spots (1-2 second bits with corrupted image). This was a bad VHS tape. I also had PD drop in to audio when in scene detect within the first few minutes. If I reboot and try it again it will go for about 30 minutes of the 2 hours before it drops out into audio. Still detecting scenes, but now at starndard play speed with audio in background. PD is latest verson 19.1.2321.0 (64 bit).

Had a thought of converting again one more time, but this time as MPG. Could there be something in the digital conversion causing the issue and using PD to convert cleans it up?

optodata

Senior Contributor Location: California, USA Joined: Sep 16, 2011 16:04 Messages: 8630 Offline

Dec 29, 2020 18:34

Quote The PC has 12 GB of ram and 250 GB of free hard disk. The file is 6.5 GB and converting it to MP4 using PD reduced it to 5.8 GB. I don't see a resource limitation.

The only way to know would be to open Task Manager and monitor the RAM and scratch disk space that PD is using.

Quote Had a thought of converting again one more time, but this time as MPG. Could there be something in the digital conversion causing the issue and using PD to convert cleans it up?

I have no idea. It may be something particular about that specific clip, and the only way for CL to see what's going on and figure out what's going on inside PD is to send them a copy when you request support.

If you're comfortable sharing it here on the forum other people can give it a try and see if the issue is present on their systems or if it's only happening to you. See this FAQ for more details.

NormRidg

Newbie Joined: Mar 17, 2013 00:38 Messages: 5 Offline

Jan 02, 2021 08:52

Quote

The only way to know would be to open Task Manager and monitor the RAM and scratch disk space that PD is using.

I have no idea. It may be something particular about that specific clip, and the only way for CL to see what's going on and figure out what's going on inside PD is to send them a copy when you request support.

If you're comfortable sharing it here on the forum other people can give it a try and see if the issue is present on their systems or if it's only happening to you. See this FAQ for more details.

Reprocessing the clip using PD was a solution that worked. My assumption is the software that converted the 2 hour clip produced a glitch that "re-producing" it through PD solved. So I am good with this solution at this time.