4K HEVC with High bitrate playback is smooth, however, the interface is laggy/not responding

[denis4o]

I have a very weird issue. I am playing a 4K high-bitrate mkv file (~58 GB, ~63 Mbps average bitrate). My hardware is more than capable IMHO: AMD Ryzen 1600 6-core CPU, GeForce GTX 1600 6 GB vRAM and 32 GB DDR4 3200 Mhz.

I am running Windows 11 22H2 x64, VLC version is 3.0.20

The playback is butter-smooth with no frame skipping, the file is served by a NAS over a 1 Gbps network with network buffers in VLC set to 3000 ms.

The issue is that the VLC interface is laggy/not responding while playing the file. I have tried different settings (mainly around video decoding) but nothing helped so far and I couldn't find a similar issue either on the forum or other resources, so I am not sure if I am the only one having that issue so decided to report it. If I want to watch the video in one go, I won't have an issue, but if I want to pause it, it takes 1-2 minutes for the pause/play button to respond which is very annoying.

Caching settings screenshot: https://cloud.mail.ru/public/LvQ3/La6e2kUhQ

Codec info screenshot: https://cloud.mail.ru/public/9fdh/mjwnQSmTR

Playback info screenshot: https://cloud.mail.ru/public/2Xs2/TfW2dswVp

I would be very grateful if someone can provide some advice.

[denis4o]

Forgot to note that the CPU utilization is around 10-15% and GPU util is between 10-15% as well. When the file is served from the spinning SATA HDD on the PC the lag in the interface is lower, but still annoying.

[Lotesdelere]

Please open Tools -> Messages (set Verbosity to 2) before you start the playback, and then paste the full resulting log here or on Pastebin.com or on Justpaste.it if it's too long.

[denis4o]

I finally managed to get a log, since VLC interface and the Messages windows become unresponsive after few clicks on the interface.

Here is the log: https://pastebin.com/482eqkgj

The average delay between when I press the pause and when the interface responds is around 11-12 seconds.

Screenshot: https://cloud.mail.ru/public/7g8t/uDXyBwLws

File size does matter IMHO; however, I think it is something else. The following file is even bigger (86 GB), served from the same location and the interface is not laggy:
Log: https://pastebin.com/V6NqD1Mj

The only difference that I personally notice is that one file contains multiple audios tracks (the one that lags the interface) while the bigger file has only one audio track (and doesn't lag the interface). Not sure if that is relevant but that is my only observation until now.

[Lotesdelere]

What is drive Z: ? An USB drive ? A network drive ?
Can you copy the file on a local drive and check if the problem still occurs ?

[denis4o]

It is a network drive (NAS) and is served over a 1 Gbps network so there is plenty of bandwidth. I also copied the file to a local disk (spinning HDD) and I had the same issue.

[Lotesdelere]

Reset the preferences (the manual way) and try again:
https://wiki.videolan.org/VSG:ResetPrefs

[denis4o]

Thanks Lotesdelere, that fixed the issue.