Playing high resolution videos even with top-notch hardware is MAXIMUM FRUSTRATION

[Mario36]

Dear all,

I'm unsing Windows 10 1803, latest driver, and 1080 Ti with an Intel Core i7 4770k. My software and hardware are top-notch.

I want to play a video with resolution 5760x2880. It is encoded with x265 Main@L6. I have encoded the video with ffmpeg. This should be a cakewalk for my hardware. I mean, every cheap mobile phone can play 1080p. So this resolution shouldn't be a problem for my 400W high-end machine, right?

Now I tried VLC, v3.0.4. It has build-in support for x265 codec hardware decoding, everyone says. I opened the video and what happened was that the first couple of frames are played, then everything freezes and video does not continue. CPU utilization stays at 70% for all cores, GPU is only marginally utilized (5%). Then after a while, VLC goes into finished mode without video actually played. No matter which setting I tried (Dx11, DXVA hardware acceleration / D3D11, OpenGL, ... video output), results are always the same. For some options, GPU is not utilized without any change in performance.

There must be something fundamentally wrong. How on earth can it be that my high-end, 2000$ hardware cannot play something simple as a high-resolution video? My hardware can render 4k games with near photo-realistic graphics. But then an 8k video should bring everything down? I can't believe that the hardware is the limit here. It's more likely that the software, especially VLC, is to blame, with some very inefficient implementation.

I'd appreciate if you could take performance into account for future releases.

VLC is famous for being compatible with a lot of different formats. But I'd hoped you could consider "resolution" just as another dimension across you want to offer maximum compatibility with.

[Hitchhiker]

Try doing a little tweaking as described in this article: http://thor.mirtna.org/tutorial-vlc.html

[Mario36]

No, OpenCL output does not improve.

I probably found the issue: ffmpeg does some special coding when creating a video from a slideshow to "avoid color subsampling" they say. But they also note that is is less compatible.

Then when I encoded in 4:2:0, it works very smooth, and it actually utilized the VPU. It was not utilized before. This is interesting.

Couldn't VLC play the video smoothly with a different color format?

[Hitchhiker]

Couldn't VLC play the video smoothly with a different color format?

I'm afraid I don't know the answer to that question.

But stick around since the devs are active I've noticed and will probably be along shortly.

[InTheWings]

There must be something fundamentally wrong. How on earth can it be that my high-end, 2000$ hardware cannot play something simple as a high-resolution video? My hardware can render 4k games with near photo-realistic graphics. But then an 8k video should bring everything down? I can't believe that the hardware is the limit here. It's more likely that the software, especially VLC, is to blame, with some very inefficient implementation.

You're pretty to blame people. Required decoding resources does not scale linearly. I highly doubt 8K is possible on any CPU.

Can you prove your video card hardware supports anything > 4K in decoding ?

[robUx4]

4:4:4 or 4:2:2 HEVC is not supported by hardware decoders, at least not in VLC/ffmpeg via DVXA. So yes you should stick to 4:2:0 if you want hardware decoding.

And software decoding of such a file (>4K) with an old 4770k is probably not going to work either.