[BUG] x265 1st pass encoding never starts

[Selur]

Encoding call is:

"/Applications/_Mes_Applis_/Video/Conversion/Hybrid.app/Contents/MacOS/ffmpeg" -y -loglevel fatal -noautorotate -nostdin -threads 4 -i "/Volumes/Racines/Akira.mkv" -map 0:0 -an -sn -vf pad=3840:2160:0:42 -pix_fmt yuv420p10le -strict -1 -vsync 0 -f yuv4mpegpipe - | "/Applications/_Mes_Applis_/Video/Conversion/Hybrid.app/Contents/MacOS/x265" --input - --y4m --uhd-bd --limit-modes --opt-ref-list-length-pps --keyint 24 --lookahead-slices 0 --pass 1 --no-slow-firstpass --bitrate 10000 --opt-qp-pps --cbqpoffs -2 --crqpoffs -2 --qpfile "/Users/Laurent/Movies/Hybrid/Akira_2160p_2021-05-25@23_03_29_4110_04.qp" --limit-refs 0 --ssim-rd --psy-rd 2.50 --rdoq-level 2 --psy-rdoq 10.00 --aq-mode 0 --vbv-maxrate 160000 --vbv-bufsize 160000 --vui-hrd-info --deblock=-1:-1 --limit-sao --range limited --colorprim bt2020 --transfer bt709 --colormatrix bt2020c --chromaloc 1 --stats "/Users/Laurent/Movies/Hybrid/Akira_2160p_generated_2021-05-25@23_03_29_4110_05.stats" --no-multi-pass-opt-analysis --output /dev/null

and still aborts with:

x265 [error]: uhd-bd: bit depth, chroma subsample, source picture type must be 10, 4:2:0, progressive
x265 [error]: x265_encoder_open() failed for Enc,
x265 [error]: Failure generating stream headers in x265

The decoding call output should produce 10bit 4:2:0 progressive, only thing that you did not enable is HDR signaling.
Try enabling:

• x265->Signaling->General Signaling->HDR
  
• x265->Signaling->HDR-10/HDR-10+->Light Level
  
• x265->Signaling->HDR-10/HDR-10+->Master Display
  

or disable the 'uhd-bd' option.

Cu Selur