HDR playback problems (mp4, 4k) with some files

[MrWGT13 21]

I backup my UHDs to mp4 and some of them (maybe 1/4 to 1/3 of the files) won't playback with hdr in emby apple tv app. Using Infuse all of them play in hdr!

Questions:

• It's the same local server, the same files/movies and Infuse plays all of them in hdr but emby app just ~70-80% in hdr. Why?
• My TV (panasonic) shows an info box on resolution/mode changes. Playing hdr files box shows up, gets blue and brighter and at the end "3840x...PQ" is shown. Files which won't play in hdr starts to get bright but falls back to "normal" box mode. It looks like that HDR "wanted to start" but something is missing. Could it be that Infuse sends some "extra headers"?
• Worked with just one file: Remux mp4 to mkv with mkvtoolnix and back to mp4 with mp4box. So video and audio stream where unchanged but after that file was playable as hdr. How is that possible?

Any help is appreciated

Sample file info:

Format                                   : MPEG-4
Format-Profil                            : Base Media
Codec-ID                                 : iso4 (iso4)
Dateigröße                               : 26,5 GiB
Dauer                                    : 1 h 57 min
Gesamte Bitrate                          : 32,1 Mb/s
Bildwiederholungsrate                    : 23,976 FPS
Kodierungs-Datum                         : 2024-03-10 21:05:24 UTC
Tagging-Datum                            : 2024-03-10 21:05:24 UTC
Kodierendes Programm                     : GPAC-2.2-rev0-gab012bbf-master

Video
ID                                       : 1
Format                                   : HEVC
Format/Info                              : High Efficiency Video Coding
Format-Profil                            : Main 10@L5@Main
HDR format                               : SMPTE ST 2086, HDR10 compatible
Codec-ID                                 : hvc1
Codec-ID/Info                            : High Efficiency Video Coding
Dauer                                    : 1 h 57 min
Bitrate                                  : 31,8 Mb/s
maximale Bitrate                         : 159 Mb/s
Breite                                   : 3 840 Pixel
Höhe                                     : 1 600 Pixel
Bildseitenverhältnis                     : 2,40:1
Modus der Bildwiederholungsrate          : konstant
Bildwiederholungsrate                    : 23,976 (24000/1001) FPS
Color space                              : YUV
Chroma subsampling                       : 4:2:0 (Type 2)
Bit depth                                : 10 bits
Bits/(Pixel*Frame)                       : 0.216
Stream-Größe                             : 26,2 GiB (99%)
Titel                                    : video
Sprache                                  : Deutsch
Kodierungs-Datum                         : 2024-03-10 21:05:24 UTC
Tagging-Datum                            : 2024-03-10 21:05:48 UTC
Color range                              : Limited
Color primaries                          : BT.2020
Transfer characteristics                 : PQ
Matrix coefficients                      : BT.2020 non-constant
Mastering display color primaries        : Display P3
Mastering display luminance              : min: 0.0001 cd/m2, max: 1000 cd/m2
mdhd_Duration                            : 7079572
Codec configuration box                  : hvcC

Audio
ID                                       : 2
Format                                   : E-AC-3
Format/Info                              : Enhanced AC-3
Commercial name                          : Dolby Digital Plus
Codec-ID                                 : ec-3
Dauer                                    : 1 h 57 min
Bitraten-Modus                           : konstant
Bitrate                                  : 384 kb/s
maximale Bitrate                         : 406 kb/s
Kanäle                                   : 6 Kanäle
Channel layout                           : L R C LFE Ls Rs
Samplingrate                             : 48,0 kHz
Bildwiederholungsrate                    : 31,250 FPS (1536 SPF)
Compression mode                         : Lossy
Stream-Größe                             : 324 MiB (1%)
Titel                                    : audio
Sprache                                  : Deutsch
Service kind                             : Complete Main
Default                                  : Ja
Alternate group                          : 1
Kodierungs-Datum                         : 2024-03-10 21:05:46 UTC
Tagging-Datum                            : 2024-03-10 21:05:48 UTC

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01:49:06.581                             : Chapter 20

 

[MrWGT13 21]

I might have found the reason:

1. video playback quality for home network was set to AUTO. A lot of newer files won't play in hdr. Maybe because i know store them in higher quality with higher bitrate
2. Changed video playback quality to 4k - 160mps. Maybe 50% of the "won't play in hdr" files now play in hdr!
3. Changed video playback quality back to auto -> files still play in hdr!

So the settings for (at least) video playback quality in emby app for apple tv won't stick correctly! (1) and (3) are both AUTO but in (3) they play in hdr!

I'm sure that all files would play in hdr if there was a setting "don't care about bitrate/resolution - play it anyway". I'm connected over wired ethernet to my local server so the network is not the bottleneck.

• Files still refusing to playback in hdr in emby app plays fine in infuse

=> i would guess, that infuse uses a "play it anyway" setting.

[Luke 37068]

Hi, we're looking into improving this. Thanks for reporting.