HDR flag check

Hi guys,

Could anybody please download this clip and check if when played on the Vero4k it’s flagged as HDR?

This is the mediainfo:

General
Complete name                            : The World in HDR in 4K (ULTRA HD)-tO01J-M3g0U.webm
Format                                   : WebM
Format version                           : Version 4 / Version 2
File size                                : 531 MiB
Duration                                 : 2 min 34 s
Overall bit rate                         : 28.8 Mb/s
Writing application                      : Lavf57.83.100
Writing library                          : Lavf57.83.100

Video
ID                                       : 1
Format                                   : VP9
Codec ID                                 : V_VP9
Duration                                 : 2 min 34 s
Width                                    : 3 840 pixels
Height                                   : 2 160 pixels
Display aspect ratio                     : 16:9
Frame rate mode                          : Constant
Frame rate                               : 59.940 FPS
Color space                              : YUV
Language                                 : English
Default                                  : Yes
Forced                                   : No
Color range                              : Limited
Color primaries                          : BT.2020
Transfer characteristics                 : PQ
Matrix coefficients                      : BT.2020 non-constant

Audio
ID                                       : 2
Format                                   : Opus
Codec ID                                 : A_OPUS
Duration                                 : 2 min 34 s
Channel(s)                               : 2 channels
Channel positions                        : Front: L R
Sampling rate                            : 48.0 kHz
Bit depth                                : 32 bits
Compression mode                         : Lossy
Language                                 : English
Default                                  : Yes
Forced                                   : No

When I play it directly using the Youtube app on my TV the image quality/colors are what I’d expect from 4K/HDR however when I play the dump on the Vero which is connected to the same TV it’s not flagged as HDR and the colors are poor.

Thanks :slight_smile:

The Vero doesn’t trigger HDR correctly when playing a VP9 video. That’s a bug that has been outstanding for a long time, now.

Ahh, good to know. That explains things. Thanks!

First I’ve heard of it.

That’s the reason why you can’t get HDR playback on YouTube.

See, for example, this thread from June 2019.

Aha! That was before I had an interweb fast enough to do such things. :smiley:

Sam said back then that he would take a look at it once 4.9 was out; I suspect he wasn’t anticipating that taking more than ten months… But it’s on my list of things to bug you guys about once 4.9 is stable. :rofl:

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That clip in the OP, grabbed with 4k Video Downloader: mediainfo on Windows or on OSMC doesn’t recognise it as HDR. VLC thinks it’s BT2020 but can’t play it. I’m wondering how @avioneta got that mediainfo.

youtube-dl 2020.03.24 and mediainfo v17.12. Nothing special.

I think I saw some notes from AML on VP9 and HDR. Trying to remember where, but there were patches for metadata to propagate to amvecm

From my side this is just a “nice to have”. I was just curious why it didn’t work as expected.

I will need to check Android engineering notes.

What’s the best way to rip these clips from YouTube?
Is it still youtube-dl or is there an online service I can use.

Obviously I need the intact bitstream.

Sorry, I’ve always used youtube-dl. There’s no re-encoding by default and I would be surprised if the pulled stream was transformed by the tool (with the default options).

I was looking at how AMLogic implement HDR for VP9 on Linux.
Currently, it’s only supported via COBALT with YouTube as the specific application.

The VP9 decoder supports passing static HDR metadata which is fixed and not specific to the video being played, which isn’t useful.

However, it is possible to prime the decoder with the correct information, but we’ll need to do this via userspace. The decoder isn’t available to extract this information from the bitstream directly.

Something to look at when it’s quiet.
Should also be tied in with how we think about custom tone mapping and overriding HDR metadata for users that want to customise things.

There are two HDR VP9 profile 2 videos on the Kodi samples page, Sam.

Links:

MEGA

https://mega.nz/#!pQEGgRwY!pD9whIlM-U9tJIA-LojxSt582BAZGfdSA5wAQLT06I4

I’m a bit wary of the Kodi samples page. Some of them are mislabelled and don’t have HDR despite saying so, but will grab them anyway and verify with MediaInfo

GitHub - streamlink/streamlink: Streamlink is a CLI utility which pipes video streams from various services into a video player Looks very promising I used the app it’s based on years ago.

It has a Save to disk option

Using youtube-dl I get the following in mediainfo of the downloaded file

Video
ID                                       : 1
Format                                   : VP9
HDR format                               : SMPTE ST 2086
Codec ID                                 : V_VP9
Duration                                 : 3 min 9 s
Width                                    : 3 840 pixels
Height                                   : 2 160 pixels
Display aspect ratio                     : 16:9
Frame rate mode                          : Constant
Frame rate                               : 30.000 FPS
Color space                              : YUV
Language                                 : English
Default                                  : Yes
Forced                                   : No
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: 0.0050 cd/m2, max: 1000 cd/m2

What version of MediaInfo?
I’m not sure that’s enough for HDR.