[BUG] x265 1st pass encoding never starts

[LaurentS]

Hi,

I use a special version you delivered to me, for Mac: Hybrid_dev_mac_2021.04.17.1

I just try to encode a mkv to make it UHD compliant. It only needs the horizontal black borders to be 2160p.
The video encoding (1st pass) never starts; there is neither progress bar nor error message.

Thanks for your help.

[Selur]

x265 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

when calling

"/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 -1  -sws_flags spline -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/Akira_2160p_2021-05-25@18_04_35_9210_06.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/Akira_2160p_generated_2021-05-25@18_04_35_9210_07.stats" --multi-pass-opt-analysis --multi-pass-opt-distortion -analysis-reuse-file "/Users/Laurent/Movies/Akira_2160p_generated.analysis" --output NUL

My guess that the problem lies with the:

--multi-pass-opt-analysis --multi-pass-opt-distortion -analysis-reuse-file "/Users/Laurent/Movies/Akira_2160p_generated.analysis"

part of the call.
-> try without those options.

Cu Selur

[LaurentS]

My guess that the problem lies with the:

--multi-pass-opt-analysis --multi-pass-opt-distortion -analysis-reuse-file "/Users/Laurent/Movies/Akira_2160p_generated.analysis"

part of the call.
-> try without those options.
____________

I cancelled these options (which are by default) :
--no-multi-pass-opt-analysis --output NUL

But I get the same answer.

I join the debug plus an image of the video specs of the source (given by MediaInfo).

[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

[LaurentS]

Hi Selur,

It seems to be working. 35 hours of encoding have started... ;-)
You made me discover the "signaling" tab. I believe it appears only with UHD encoding. I didn't see it before. 
Thanks again for helping me using the fantastic tool Hybrid is.

//////////

Actually it was stuck at 1% video encoding. I have to improve my knowledge of the numerous settings. I'll ask you if I really can't find the answer myself.

[Selur]

Nope, it's always there,..

Cu Selur

[LaurentS]

OK, I'm sorry but I can't find what setting is wrong.
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.
I ignored the audio to get faster to the video encoding.
I join the debug.

Please help

[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

[Selur]

Okay, small update:

• I can reproduce the issue.
  
• It has nothing to do with 1pass encoding (also happens with 2pass encoding)
  
• Problem happens when '--bd-uhd' is used.
  
• Happens on Windows and MacOS. (haven't tested on Linux, but probably the same)
  

-> looking into it some more

Okay, seems like '--uhd-bd' does not force the options, but simply checks them.
-> will adjust Hybrid to not remove adjusted the options.

Cu Selur

[LaurentS]

Okay, small update:

• I can reproduce the issue.
  
• It has nothing to do with 1pass encoding (also happens with 2pass encoding)
  
• Problem happens when '--bd-uhd' is used.
  
• Happens on Windows and MacOS. (haven't tested on Linux, but probably the same)
  

-> looking into it some more

Okay, seems like '--uhd-bd' does not force the options, but simply checks them.
-> will adjust Hybrid to not remove adjusted the options.

Cu Selur

Yep, I confirm the option "uhd bd" only checks if the settings are compliant. I saw that when I tried to change many settings. I unchecked/checked the 'uhd bd' box many times and it didn't change a thing.
I first thought it would create some settings to be BD compliant.
But when I read this was an experimental option, I didn't complain : I was happy enough this was already existing because it's the main purpose of Hybrid for my usage.

So I went through all the encoding settings to be sure I wasn't making any mistake, though I don't know much about it. Then you reassure me saying it's not my fault

I wish you luck and time to find the answer.
And thanks again.

Laurent