CRF is not as important as --preset, use --preset slow or --preset veryslow
I personally use --preset placebo
Wrong. CRF control the size by reducing or increasing the quantizers, the presets control the quality of the predictions.
It's called "placebo" for a reason
Actually above 5 the references and the constructive b-frames aren't really that strong and in most cases there is another good enough frame for reference/ As long as motion search and the sub-pixel estimation are fine the other settings will just reflect on the final size of the files (by small margin) and the quality will be more or less the same, so the preset aren't really THAT useful especially if you want to speed-up the encoder without big trade off when it comes to quality. Unless the encoding is really slow, you should stick with the highest "sane" settings (for example: it's better to max-out all encoder's settings than using --tesa instead of --umh). Keep in mind that the encode is one time thing, while the video will be stored on a lot of drives, so you should try to compress as much as you can.
--CRF is more or less the quantization value of the blocks, but unlike the --QP (constant quantizers) it takes in mind other settings like qcomp, ipratio and etc.
crf values of the 10bit encoder start from -13 to keep consistency with the 8bit one, so the crf has the same meaning and the last I checked the max was still 51 (you can go with --qp 81 if you so desire, but I doubt that it preduces anything watchable)
So there is no actual magic value for the crf, depending on the other settings crf 14 may be bad or crf 20 can be a bloat, but on SD content you need higher quality (lower crf), since artifacts will be much more visible after upscale. 17 was just an example. Run some test and choose the one that suits your needs (i.e. where your encode look like the source or almost like it). What I actually wanted to say is that --tune anime is quite bad and you shouldn't really use it or at least increase the --aq-strength
Don't worry! I'm using x264. My full command line is:
where $fi is filename, with AVS file of form
wine avs2yuv $fi.avs - | ffmpeg -hide_banner -f yuv4mpegpipe -i - -i $fi.flac -map 0:v:0 -map 1:a:0 -sws_flags lanczos+accurate_rnd+full_chroma_int+full_chroma_inp -vf crop=704:480:10:0,scale=640:480,setdar=4/3 -c:v libx264 -c:a copy -crf 17 -preset veryslow -tune animation $fi.mkv
AviSource("FILENAME",fourCC="dvsd").KillAudio() #Using Cedocida DV Codec
You should use x264, not ffmpeg (if I'm reading your script correctly? -no idea what you are actually doing in the first one). Also for telecined content, you can use frame matching like TFM with QTGMC on fail (I can agree that qtgmc with EdiMode="NNEDI3" can do a single field restoration quite good, but it should be your last option). apply deinterlacer/ITVC after the decode and then you can denoise and resize in 16bit depth and encode proper 10bit file.