[BUG] x265 1st pass encoding never starts

[Selur]

I really tried to apply the same encoding settings as from the source but Hybrid seems to act as if the video source wasn't 10 bits 4:2:0 HDR. But it is, according to MediaInfo.

You think that why?
Since the encoding call:

"/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 scale=3840:2072,pad=3840:2160:0:44 -pix_fmt yuv420p10le -strict -1 -vsync 0  -sws_flags spline -f yuv4mpegpipe - | "/Applications/_Mes_Applis_/Video/Conversion/Hybrid.app/Contents/MacOS/x265" --frame-threads 6 --input - --y4m --uhd-bd --me dia --max-merge 2 --no-early-skip --no-strong-intra-smoothing --opt-ref-list-length-pps --keyint 24 --bframes 6 --b-adapt 1 --lookahead-slices 0 --qblur 0.60 --crf 14.00 --opt-qp-pps --cbqpoffs -2 --crqpoffs -2 --qpfile "/Users/Laurent/Movies/Hybrid/Akira_2160p_2021-05-26@22_26_48_8310_02.qp" --limit-refs 0 --psy-rd 2.50 --aq-mode 1 --aq-strength 0.4 --vbv-maxrate 160000 --vbv-bufsize 160000 --vui-hrd-info --deblock=-1:-1 --selective-sao 0 --range limited --colorprim bt2020 --transfer smpte2084 --colormatrix bt2020nc --chromaloc 1 --master-display "G(8500,39850)B(6550,2300)R(35400,14600)WP(15635,16450)L(10000000,50)" --max-cll 1000,369 --hdr --hdr-opt --output "/Users/Laurent/Movies/Hybrid/2021-05-26@22_26_48_8310_03.265"

does look correct.
It:

• encodes 10bit 4:2:0 (-pix_fmt yuv420p10le)
  
• uses uhd-bd signaling (--uhd-bd )
  
• signals the hdr-10 meta-data (--hdr --range limited --colorprim bt2020 --transfer smpte2084 --colormatrix bt2020nc --chromaloc 1 --master-display "G(8500,39850)B(6550,2300)R(35400,14600)WP(15635,16450)L(10000000,50)" --max-cll 1000,369)
  

Not sure whether it's a problem with the x265 version which comes with the build you use or with your setup (MacOS 10.4), the encoding settings look fine.
-> I'll try to reproduce the issue in a mac VM after work today. (only thing I usually wouldn't use is the 'hrd' signaling, but that shoudl not cause an issue)

Cu Selur