Need help/advice with Intel NUC buffering problems

duffbeer · February 7, 2021 at 12:15 PM

I really hope that someone here can offer me some advice as I have been trying to resolve this issue myself for a long time with no success.

My setup is as follows:

NUC8i3BEK with 8gb of RAM running the latest bios with Libreelec 9.2.6. The only thing I use Kodi for is to watch my media files stored on my NAS, I have no additional addons and I do not watch anything via http. My Synology NAS is connected using homeplugs (I know these are not the best solution but they have worked without issue for a few years and I have no way of running a network cable between the 2 rooms.) The media files are streamed using NFS protocol rather than SMB.

I have been using this setup for a few years with no issues, 1080p files play perfectly both AVC and HEVC. The problems began when I started watching 4K media files.

These files will play OK until the bitrate increases during a high action scene or similar. The high bitrate causes the video to freeze and then after a couple of seconds the blue circular icon appears on screen and counts up to 100 while the buffer is refreshed (I assume this is what's happening.)

I understand that the home plugs are probably the issue here and they just can't keep up with the higher level of data throughput. After a little research I discovered the video cache settings page on the Kodi wiki. I have tried a few different variations of the advancedsettings file but nothing seems to work for me. In fact, they all make the playback worse not just with 4K but even with the 1080p files that play correctly with the default settings.

When I change the video cache settings it causes the video to freeze within 1-2 seconds of the start and it does not display the blue circular icon that I mentioned earlier, it just freezes and does nothing until I press stop. I assume I'm doing something wrong here but I can't figure it out, surely these cache settings should help the file to play correctly? As I mentioned earlier, the 4K files play mostly OK with just a few freezes during the high bitrate scenes so I don't think it is too far away from working OK.

I have tried the following advancedsettings.xml flies:

<cache>

</cache>

</advancedsettings>

I tried inceasiing and decreasing the readfactor and also buffermode 4

<cache>

</cache>

</advancedsettings>

Also tried with buffermode 4

<cache>

</cache>

</advancedsettings>

I was surpised this one didn't work for me either because according to the wiki page, setting the memorysize to 0 means it should buffer the data to the local hard drive rather than the RAM. I really thought this would make some difference but it behaves exactly the same as all the other files above.

Every one of these options makes the playback worse in my setup and I just don't understand why. I would be really grateful for any advice as I'm completely stuck and I don't know what else to try.

**chewitt** · February 7, 2021 at 2:26 PM Official Post

Cache settings can smooth out the ebbs/flows of a wireless connection where you get sudden drops in bandwidth, because buffering more data helps paper over the gap when it happens (and then normal throughput resumes). However it can *never* solve the more fundamental problem of there not being enough bandwidth for a sustained large file transfer. In fact, since you force it to queue more data before play start, if you saturate the link and the supply of data cannot keep up, you will also wait longer for it to resume because we need to buffer into a larger cache. Users always add cache and this negatively impacts the problem, ergo reducing the cache size might improve it, albeit there's a razor thin margin involved. All connections fluctuate a little, so a little cache always helps, and by default Kodi uses a little cache.

TL/DR; If the network can't keep up the solution is always to fix the network not fiddle with cache settings.