(This post has been edited with new information)

The LG Cx series of OLED TVs have terrible network chipsets in them: They can do more than 100mbps over 5GHz wifi, but can only do 100mbit/s over ethernet (my experiments with a USB-to-ethernet adapter were mixed). So what happens if you want to stream to your TV over ethernet because you can’t use wi-fi?

Included below is an ffmpeg script I’ve used to transcode UHD 4k blu-ray rips down to a bandwidth that can be handled without trouble using my LG C8’s ethernet connection, which I used during a period when I was unable to use the TV over 5GHz wifi (since corrected, thankfully). It leverages a modern nvidia card to do the transcode without any CPU usage, and preserves the HDR10 information. The end result is worse than the source if you pixel-peep, but if you’re sitting 10 feet away from your projector, it’s perfectly fine — and it’s certainly better than a blu-ray rip of the same material. Here’s the script:

REM This creates a Plex Versions proxy that preserves as much quality
REM as possible without exceeding an LG C8's ethernet 100mbit/s capabilities.
REM Call this batch file from the plex directory containing your main movie.
REM
REM The 120M bufsize represents a 3-second window @ 40M vbr that a max of 60M
REM can be sustained.
REM

mkdir "Plex Versions\LG C8"

for %%a in ("*.*") do ffmpeg -find_stream_info -hwaccel auto -i "%%a" -map 0 -c copy -c:v hevc_nvenc -pix_fmt p010le -tune:v hq -preset:v p7 -color_primaries bt2020 -color_trc smpte2084 -colorspace bt2020nc -spatial_aq:v 1 -temporal_aq:v 1 -b_ref_mode middle -profile:v main10 -tier:v high -b:v 40M -maxrate:v 60M -bufsize:v 120M "Plex Versions\LG C8\%%~na.mkv"