Troubleshooting HDR playback on TV

[davexnet]

Background:
I'm trying to find out why HDR10 media on Amazon Prime Video (through the TV app) looks washed out on my LG TV,
has very bright highlights, but shadow detail is in the mid-grey range. The colors are also off, some shows looking
like saturated pastel shades. (Their new show "Upload" is one of the worst).

Yet, YouTube Demos and other sample files I've found on the net, both HDR10 and HDR10+ look
great.

I've been asking on the LG and Amazon forums if anybody has any idea, but so far no response, accept
somebody mentioned it sounds like a tone mapping problem. This seems reasonable, but what does it mean ?
Something wrong in the metadata? (particularly in light of what I found)

I recently got lucky and found something that may help solve the problem - If I knew what I was looking for!
I searched the internet for further HDR samples and I finally found one that exhibits this same washed out look -
but now I can see the file specs.

Just out of interest I re-encoded it in Vidcoder using HEVC/Main10 and this file looks normal on my TV, HDR,
proper color and good brightness range. (To my mind this adds credence to my metadata theory)

Here's the mediainfo of the re-encode and the source, I can provide file samples if anybody would
like to to see them.

My re-encode (720p)

General
Complete name                            : C:\Users\davex\Desktop\DEMO-720p.mp4
Format                                   : MPEG-4
Format profile                           : Base Media / Version 2
Codec ID                                 : mp42 (isom/iso2/mp41)
File size                                : 6.26 MiB
Duration                                 : 59 s 310 ms
Overall bit rate                         : 886 kb/s
Encoded date                             : UTC 2020-06-10 20:58:13
Tagged date                              : UTC 2020-06-10 20:58:13
Writing application                      : HandBrake 20200605160604-75bae14a8-master 2020060501

Video
ID                                       : 1
Format                                   : HEVC
Format/Info                              : High Efficiency Video Coding
Format profile                           : Main 10@L4@High
Codec ID                                 : hvc1
Codec ID/Info                            : High Efficiency Video Coding
Duration                                 : 59 s 310 ms
Bit rate                                 : 882 kb/s
Width                                    : 1 280 pixels
Height                                   : 536 pixels
Display aspect ratio                     : 2.40:1
Frame rate mode                          : Variable
Frame rate                               : 23.976 (24000/1001) FPS
Minimum frame rate                       : 23.974 FPS
Maximum frame rate                       : 23.981 FPS
Color space                              : YUV
Chroma subsampling                       : 4:2:0
Bit depth                                : 10 bits
Bits/(Pixel*Frame)                       : 0.054
Stream size                              : 6.24 MiB (100%)
Writing library                          : x265 3.2.1+1-b5c86a64bbbe:[Windows][GCC 9.2.0][64 bit] 10bit
Encoding settings                        : cpuid=1064959 / frame-threads=2 / numa-pools=4 / wpp / no-pmode / no-pme / no-psnr / no-ssim /
 log-level=2 / input-csp=1 / input-res=1280x536 / interlace=0 / total-frames=0 / level-idc=40 / high-tier=1 / uhd-bd=0 / ref=3 /
 no-allow-non-conformance / no-repeat-headers / annexb / no-aud / no-hrd / info / hash=0 / no-temporal-layers / open-gop /
 min-keyint=24 / keyint=240 / gop-lookahead=0 / bframes=4 / b-adapt=2 / b-pyramid / bframe-bias=0 / rc-lookahead=20 /
 lookahead-slices=0 / scenecut=40 / radl=0 / no-splice / no-intra-refresh / ctu=64 / min-cu-size=8 / no-rect / no-amp /
 max-tu-size=32 / tu-inter-depth=1 / tu-intra-depth=1 / limit-tu=0 / rdoq-level=0 / dynamic-rd=0.00 / no-ssim-rd / signhide /
 no-tskip / nr-intra=0 / nr-inter=0 / no-constrained-intra / strong-intra-smoothing / max-merge=3 / limit-refs=1 / no-limit-modes /
 me=1 / subme=2 / merange=57 / temporal-mvp / no-hme / weightp / no-weightb / no-analyze-src-pics / deblock=0:0 / sao /
 no-sao-non-deblock / rd=3 / selective-sao=4 / early-skip / rskip / no-fast-intra / no-tskip-fast / no-cu-lossless / b-intra /
 no-splitrd-skip / rdpenalty=0 / psy-rd=2.00 / psy-rdoq=0.00 / no-rd-refine / no-lossless / cbqpoffs=0 / crqpoffs=0 / rc=crf /
 crf=21.0 / qcomp=0.60 / qpstep=4 / stats-write=0 / stats-read=0 / vbv-maxrate=30000 / vbv-bufsize=30000 / vbv-init=0.9 /
 crf-max=0.0 / crf-min=0.0 / ipratio=1.40 / pbratio=1.30 / aq-mode=2 / aq-strength=1.00 / cutree / zone-count=0 / no-strict-cbr /
 qg-size=32 / no-rc-grain / qpmax=69 / qpmin=0 / no-const-vbv / sar=1 / overscan=0 / videoformat=5 / range=0 / colorprim=9 /
 transfer=16 / colormatrix=9 / chromaloc=0 / display-window=0 / cll=0,0 / min-luma=0 / max-luma=1023 / log2-max-poc-lsb=8 /
 vui-timing-info / vui-hrd-info / slices=1 / no-opt-qp-pps / no-opt-ref-list-length-pps / no-multi-pass-opt-rps /
 scenecut-bias=0.05 / no-opt-cu-delta-qp / no-aq-motion / no-hdr / no-hdr-opt / no-dhdr10-opt / no-idr-recovery-sei /
 analysis-reuse-level=5 / scale-factor=0 / refine-intra=0 / refine-inter=0 / refine-mv=1 / refine-ctu-distortion=0 /
 no-limit-sao / ctu-info=0 / no-lowpass-dct / refine-analysis-type=0 / copy-pic=1 / max-ausize-factor=1.0 / no-dynamic-refine /
 no-single-sei / no-hevc-aq / no-svt / no-field / qp-adaptation-range=1.00
Encoded date                             : UTC 2020-06-10 20:58:13
Tagged date                              : UTC 2020-06-10 20:58:13
Color range                              : Limited
Color primaries                          : BT.2020
Transfer characteristics                 : PQ
Matrix coefficients                      : BT.2020 non-constant
Codec configuration box                  : hvcC

Original file: (4k)

General
Unique ID                                : 280667973729367058982597086729421534019 (0xD326AF7D29C2EC532F16E12DC81D3343)
Complete name                            : C:\Users\davex\Desktop\DEMO.mkv
Format                                   : Matroska
Format version                           : Version 4
File size                                : 88.0 MiB
Duration                                 : 59 s 407 ms
Overall bit rate                         : 12.4 Mb/s
Writing application                      : Lavf58.20.100
Writing library                          : Lavf58.20.100
ErrorDetectionType                       : Per level 1

Video
ID                                       : 1
Format                                   : HEVC
Format/Info                              : High Efficiency Video Coding
Format profile                           : Main 10@L5.1@High
Codec ID                                 : V_MPEGH/ISO/HEVC
Duration                                 : 59 s 310 ms
Bit rate                                 : 12.2 Mb/s
Width                                    : 3 840 pixels
Height                                   : 1 608 pixels
Display aspect ratio                     : 2.40:1
Frame rate mode                          : Constant
Frame rate                               : 23.976 (24000/1001) FPS
Color space                              : YUV
Chroma subsampling                       : 4:2:0
Bit depth                                : 10 bits
Bits/(Pixel*Frame)                       : 0.082
Stream size                              : 86.1 MiB (98%)
Writing library                          : x265 3.2+15-04db2bfee5d6:[Windows][GCC 6.3.0][64 bit] 10bit
Encoding settings                        : cpuid=1176575 / frame-threads=5 / numa-pools=36 / wpp / pmode / no-pme / no-psnr / no-ssim /
 log-level=2 / input-csp=1 / input-res=3840x1608 / interlace=0 / total-frames=0 / level-idc=51 / high-tier=1 / uhd-bd=0 / ref=5 /
 no-allow-non-conformance / repeat-headers / annexb / aud / hrd / info / hash=0 / no-temporal-layers / no-open-gop / min-keyint=23 /
 keyint=250 / gop-lookahead=0 / bframes=11 / b-adapt=2 / b-pyramid / bframe-bias=0 / rc-lookahead=40 / lookahead-slices=0 / scenecut=40 /
 radl=0 / no-splice / no-intra-refresh / ctu=64 / min-cu-size=8 / no-rect / no-amp / max-tu-size=32 / tu-inter-depth=3 / tu-intra-depth=3 /
 limit-tu=4 / rdoq-level=2 / dynamic-rd=0.00 / no-ssim-rd / signhide / no-tskip / nr-intra=0 / nr-inter=0 / no-constrained-intra /
 no-strong-intra-smoothing / max-merge=4 / limit-refs=1 / limit-modes / me=3 / subme=4 / merange=57 / temporal-mvp / no-frame-dup /
 no-hme / weightp / weightb / no-analyze-src-pics / deblock=-3:-3 / no-sao / no-sao-non-deblock / rd=6 / selective-sao=0 / no-early-skip /
 no-rskip / no-fast-intra / no-tskip-fast / no-cu-lossless / b-intra / no-splitrd-skip / rdpenalty=0 / psy-rd=2.00 / psy-rdoq=1.00 /
 no-rd-refine / no-lossless / cbqpoffs=0 / crqpoffs=0 / rc=crf / crf=21.2 / qcomp=0.60 / qpstep=4 / stats-write=0 / stats-read=0 /
 vbv-maxrate=160000 / vbv-bufsize=160000 / vbv-init=0.9 / crf-max=0.0 / crf-min=0.0 / ipratio=1.30 / pbratio=1.20 / aq-mode=3 /
 aq-strength=0.70 / no-cutree / zone-count=0 / no-strict-cbr / qg-size=32 / no-rc-grain / qpmax=69 / qpmin=0 / no-const-vbv /
 sar=1 / overscan=0 / videoformat=5 / range=0 / colorprim=9 / transfer=16 / colormatrix=9 / chromaloc=0 /
 display-window=0 / cll=0,0 / min-luma=0 / max-luma=1023 / log2-max-poc-lsb=8 / vui-timing-info / vui-hrd-info / slices=1 / no-opt-qp-pps /
 no-opt-ref-list-length-pps / no-multi-pass-opt-rps / scenecut-bias=0.05 / no-opt-cu-delta-qp / no-aq-motion / hdr / hdr-opt / no-dhdr10-opt /
 no-idr-recovery-sei / analysis-reuse-level=5 / scale-factor=0 / refine-intra=0 / refine-inter=0 / refine-mv=1 / refine-ctu-distortion=0 /
 no-limit-sao / ctu-info=0 / no-lowpass-dct / refine-analysis-type=0 / copy-pic=1 / max-ausize-factor=1.0 / no-dynamic-refine / no-single-sei /
 no-hevc-aq / no-svt / no-field / qp-adaptation-range=1.00 / no-scenecut-aware-qp
Default                                  : Yes
Forced                                   : No
Color range                              : Limited
Color primaries                          : BT.2020
Transfer characteristics                 : PQ
Matrix coefficients                      : BT.2020 non-constant

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