Improving CodeFormer videos

[Selur]

The problem is that the "pipe" it is the weakest link in the encoding chain, the "ffmpeg" (Vapoursynth enabled version) is able to avoid the "pipe" in this sense is more robust than

a. compiling ffmpeg with Vapoursynth support requires compiling Vapoursynth beforehand
b. whenever a dependecy of ffmpeg fails building ffmpeg fails
c. whenever an api change happens the vapoursynth library for ffmpeg needs adjustment
adding another dependecy doesn't really sound appealing to me.

What do you call more robust?
Have you tried using rawvideo pipes instead of yuv4mpegpipe, which isn't supported by all encoders.
x264 does support both, does using something like:

"D:\Programs\Hybrid\64bit\Vapoursynth\ffmpeg.exe" -y -loglevel fatal -f vapoursynth -i CodeFormerTest6-001-BAD-1.vpy -noautorotate -nostdin -threads 8 -map 0:0 -an -sn -color_primaries bt470bg -color_trc smpte170m -colorspace bt470bg -color_range tv  -pix_fmt yuv420p -vsync 0 -f rawvideo - | x264 --preset veryfast --crf 18.00 --profile high --level 5.1 --ref 3 --direct auto --b-adapt 0 --sync-lookahead 17 --qcomp 0.50 --rc-lookahead 40 --qpmax 51 --partitions i4x4,p8x8,b8x8 --no-fast-pskip --subme 5 --aq-mode 0 --vbv-maxrate 300000 --vbv-bufsize 300000 --sar 1:1 --non-deterministic --range tv --colormatrix bt470bg --demuxer raw --input-res 640x352 --input-csp i420 --input-range tv --input-depth 8 --fps 25/1 --output-depth 8 --output "2024-02-14@15_36_30_3410_01.264" -

work for you?
(not that the paths, vui settings, bitdepth, fps, etc need to be adjusted)
If not then ffmpeg only works in your example since it has a special handling for yuv4mpegpipe output.

Cu Selur