Cannot install nvfbc patch

Hi, I’m trying to install the nvfbc patch from (GitHub - keylase/nvidia-patch: This patch removes restriction on maximum number of simultaneous NVENC video encoding sessions imposed by Nvidia to consumer-grade GPUs.) for optimal performance when streaming with Sunshine but I get the following error.

Detected nvidia driver version: 555.42.02
Error: Could not find bytes '\x83\xfe\x01\x73\x08\x48' to patch in '/usr/lib64/libnvidia-fbc.so.555.42.02'.

I’ve tried the default linux-cachyos-nvidia as well nvidia-dkms thinking it might be an issue with some cachyos customisations but no luck.

I’ve also tried nvlax-git from the cachyos repo, which seems to install the nvenc patch correctly but errors out when it tries to apply the fbc patch.

[+] libnvidia-encode.so
[+] patched successfully
Assertion '(!((ZydisDecoderDecodeFull(&decoder, v_backtrack_bytes.data(), v_backtrack_bytes.size(), &instr, operands)) & 0x80000000u))' failed (ERROR)
  in file lax_fbc.cc, line 85
  function: int main(int, char**)
terminate called after throwing an instance of 'ppk::assert::AssertionException'
  what():  
error: command terminated by signal 6: Aborted

Any ideas? On drivers prior to 555 I was able to apply the patch with no issues.

Hi,

This is already done in the cachyos driver. You dont need to do this.

1 Like

That would certainly explain why the bytes don’t match.

I wonder why sunshine isn’t detecting it? Off to do some more troubleshooting I guess. Thanks

I dont know why.
You can see here out its applied:

We have today updated the driver to apply the 555 patch for it. Before it was broken. Maybe you need to update your system.

2 Likes

After some tinkering with older known-working drivers, it looks like the issue was the current stable version of sunshine not correctly detecting CUDA, as it would also throw

Warning: Attempting to use NVENC without CUDA support. Reverting back to GPU -> RAM -> GPU

when using KMS capture under Wayland.

The latest prerelease v2024.610.122248 build from github or the sunshine-git package on the AUR both work fine on the latest driver (555.52.04)