ELI5 why h265 videos won't work

[CogadhTaibhse]

So I bought a Qnap TS-433 a few months back, very happy with it so far, although I wasn't aware that Jellyfin doesn't work on Qnap ARM until I tried to set it up, but no worries I can deal with using Plex.

I am connected to the same network as the NAS but I am on WiFi and Plex works fine until I start to watch any content other than h264, the CPU usage skyrockets and the video just buffers over and over. From my brief understanding of h265 this is normal, it can store the same amount of information as h264 but in a smaller size and the CPU has to work harder because of that. But when I use file explorer to open the h265 movie file it works no problem (I have a feeling this is because my PC is doing the legwork instead of the NAS itself?). I have also seen people say on Reddit that it should work because I'm on the same network as my NAS, and I've also seen someone say that because h265 has so many different licenses involved that that is why it struggles to decode it.

 

Can someone please ELI5 how all this works and if I would be able to get h265 encoded videos to run on my NAS? Only having h264 videos isn't a showstopper for me but it is a bit inconvenient with the bigger file sizes.

[Kilrah]

You need to disable transcoding of videos since the NAS isn't gonna be able to do that. Then it'll just stream the files as is and rely on the playback devices ability to support the various formats.

[OddOod]

Welcome to the forums!

Not exactly suitable for 5 year olds but I can break it down a bit. First, you are mostly correct in your suppositions. h265 can encode the same quality in less space, the reason you have no trouble viewing it on your PC not through plex is because the PC is doing the heavy lifting and the NAS is just serving the file, the people on Reddit are wrong.

 

Now, the reason your NAS is struggling trying to transcode the files in realtime is that it doesn't have what's called a hardware decoder (MOST things don't have hardware decoders for h265 outside of GPUs) and so it has to fall back on software decoding. This is kind of like trying to get your CPU which is pretty good at doing a lot of different types of tasks to do the job of your GPU which is absolutely amazing at doing exactly one thing, linear algebra, but absolute trash at doing anything else. 

[tkitch]

simple answer:
The CPU in the QNAP is wimpy AF, and can't handle decoding h.265, you'd need a much more powerful box to do that.

 

You'd want to stream that directly to your PC and let the PC handle it.  (there's a reason people use dedicated GPUs in NAS boxes for transcoding video)

[OddOod]

As for what you can do in this situation, it kinda depends on what machines you're using to consume plex. If those machines support h265 decode natively, you can just turn off transcoding. But if they don't, you're gonna have to add a server to host plex (could be an 8 year old workstation with a 960 in it, just something that can handle the compute) or you're gonna have to use Tdarr/handbrake on your PC to reencode the files. 

[CogadhTaibhse]

10 minutes ago, Kilrah said:

You need to disable transcoding of videos since the NAS isn't gonna be able to do that. Then it'll just stream the files as is and rely on the playback devices ability to support the various formats.

Thank you, turning off transcoding worked

 

5 minutes ago, OddOod said:

As for what you can do in this situation, it kinda depends on what machines you're using to consume plex. If those machines support h265 decode natively, you can just turn off transcoding. But if they don't, you're gonna have to add a server to host plex (could be an 8 year old workstation with a 960 in it, just something that can handle the compute) or you're gonna have to use Tdarr/handbrake on your PC to reencode the files. 

Is there somewhere I can find what devices support decoding natively? I will consume a lot of the media through my PC but sometimes I will want to watch it through my PS4, firestick or laptop.

 

[Bersella AI]

1 minute ago, John Talbot said:

Thank you, turning off transcoding worked

 

Is there somewhere I can find what devices support decoding natively? I will consume a lot of the media through my PC but sometimes I will want to watch it through my PS4, firestick or laptop.

 

For x86 platforms, grab the software DXVA Checker and check out available hardware codecs from the GPU. The website also offers codec lists of modern GPUs for quick reference.

For TV boxes or sticks, you may check out the model of its SoC and/or search for its specifications, in which its available codecs should be listed. The website AndroidPCTV can also be referred to for more intuitive reviews.

 

Also, the SoC in PlayStation 4 may unfortunately be too ancient to decode H.265 videos.