hdr: problem with mpv tone-mapping and/or wide color gamut with hdr10 content on iPhone Xs

[mawazi 1]

iOS 12.4.1

Emby for iOS 1.8.3

Emby Server 4.2.1.0

 

I've recently begun ripping 4k/HDR10 content. It is correctly passed through the LG WebOS Emby app as HDR, which is great. Unfortunately, on my iPhone Xs, there is either bad tone-mapping happening or poor handling of 10-bit wide color gamut , basically unwatchable. Tested on Windows mpv with defaults, tone-mapping and wide color gamut are handled properly.

 

These videos use mkv containers, with hdr metadata set using mkvtoolnix.

 

Some screenshots from my iPhone (from Star Trek Beyond and Doctor Who: Twice Upon a Time):

 

Here's the mediainfo on the Star Trek Beyond HEVC stream, the Paramount mountain and the craggy rocks are from it (I have resized my videos from 4k down to 1080p, I'm more interested in the HDR and wide-color gamut):

 

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                                 : 2 h 2 min
Bit rate                                 : 13.9 Mb/s
Width                                    : 1 920 pixels
Height                                   : 1 080 pixels
Display aspect ratio                     : 16:9
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)                       : 0.280
Stream size                              : 11.9 GiB (96%)
Writing library                          : x265 3.1+11-de920e0a3183:[Windows][GCC 9.1.1][64 bit] 10bit
Encoding settings                        : ....... <snipped>
Language                                 : English
Default                                  : Yes
Forced                                   : No
Color range                              : Limited
Color primaries                          : BT.2020
Transfer characteristics                 : PQ
Matrix coefficients                      : BT.2020 non-constant

 

Any thoughts?

 

Thanks.

Edited September 18, 2019 by mawazi

[mawazi 1]

Here's a comparison image from mpv in Windows. ignore the garbage at the very top and bottom:

[Luke 37047]

@@mawazi, on apple platforms mpv has some limitations regarding hdr. We're looking into this, first by updating our mpv libs and trying out the latest improvements, and then if that doesn't pan out we'll look into what our options are. Thanks.

[mac110 0]

i also have this problems with my ipad pro 2018. Is there still no fix?

[Luke 37047]

We're looking into this. Thanks for reporting.