Update nixos/modules/services/video/frigate.nix

Co-authored-by: Atemu <[email protected]>

nixos/modules/services/video/frigate.nix

@@ -137,12 +137,19 @@ in
       default = null;
       example = "radeonsi";
       description = ''
-        VA-API driver to use for video acceleration. Use together with `settings.ffmpeg.hwaccel_args`.
+        Force usage of a particular VA-API driver for video acceleration. Use together with `settings.ffmpeg.hwaccel_args`.
+
+        Setting this *is not required* for VA-API to work but it can help steer VA-API towards the correct card if you have multiple.
+
+        :::{.note}
+        You must configure a VA-API driver package for VA-API to work, regardless of this setting.
+        AMDGPUs require {option}`hardware.graphics.enable` and most Intel GPUs need `pkgs.intel-media-driver` in {option}`hardware.graphics.extraPackages`.
+        :::
+
+        See also:
 
         - https://docs.frigate.video/configuration/hardware_acceleration
         - https://docs.frigate.video/configuration/ffmpeg_presets#hwaccel-presets
-
-        Requires a VA-API driver to be installed through `hardware.graphics.extraPackages`.
       '';
     };