madVR stuttering 4K playback

[krzaku]

Hi. I'm having troubles playing my 4K remux files. Specifically they seem to stutter a lot when used with madVR + MPC-HC. This issue only occurs in high bitrate (remux, 70+ mbit/s) 4K files. Haven't tested regular 4K videos, but remux 1080p files (20-30 mbit/s) work fine. madVR struggles greatly, while VLC has no issues with those exact same files. Computer specs: VM machine, i7-4790k of which 6 cores are passed to the VM, GTX 1070 passed through to the VM.

The screenshot attached shows DXVA is used, but this also happens in fullscreen, where only bilinear chroma-upscaling is done. Encoder is set to hardware DXVA2.

[huhn]

can you upload the screen somewhere else?

[krzaku]

Here it is: https://i.imgur.com/zt3f9pv.jpg

[Warner306]

The decoder queue is empty. The video isn't being decoded correctly. Try another form of hardware decoding, like D3D11 Automatic (Native).

[mytbyte]

Hi. I'm having troubles playing my 4K remux files. Specifically they seem to stutter a lot when used with madVR + MPC-HC. This issue only occurs in high bitrate (remux, 70+ mbit/s) 4K files. Haven't tested regular 4K videos, but remux 1080p files (20-30 mbit/s) work fine. madVR struggles greatly, while VLC has no issues with those exact same files. Computer specs: VM machine, i7-4790k of which 6 cores are passed to the VM, GTX 1070 passed through to the VM.

The screenshot attached shows DXVA is used, but this also happens in fullscreen, where only bilinear chroma-upscaling is done. Encoder is set to hardware DXVA2.

No, sir, your OSD shows DXVA decoding is NOT in effect (it should also read DXVA2 or DXVA11 next to p10, 10 bit, 4:2:0). Check your gfx card is listed under Active Hardware Accelerator in LAV filters ..are UHD (4K) and HEVC checked?

[krzaku]

Switching to D3D11 decoding worked, thanks! Any idea why it is like this? I'm sure I set DXVA2 in LAV Decoder settings, here's a screenshot: https://i.imgur.com/y6pP3ZX.png

Anyway, I still can't seem to get HDR to work properly. I set screen resolution to 4k@30hz, color settings to YCbCr422, color depth to 12 bit. Set madVR to passthrough HDR to the display. When playing a video the display switches to HDR mode, but the colors are desaturated. Here's a ctrl+j screenshot when in HDR mode: https://i.imgur.com/COxtfiW.png

Another issue is the audio seems to go out of sync over a longer period of time, any idea what this may be about?

[huhn]

how much PCIe lanes do you get in this setup?

[krzaku]

Full 16 lanes.

[nevcairiel]

Switching to D3D11 decoding worked, thanks! Any idea why it is like this? I'm sure I set DXVA2 in LAV Decoder settings, here's a screenshot: https://i.imgur.com/y6pP3ZX.png


DXVA2-CopyBack has a certain overhead in memory bandwith, add to that through a VM and it can quite possibly bottleneck decoding. D3D11 Native or DXVA2 Native are far more efficient.

[krzaku]

Huh, I could've sworn I tried DXVA2 Native before, but I guess I didn't because selecting that now also fixes the issue I was having in the OP.

Any idea about the 2 issues I described a few posts above?