Confused about 4K & HDR

[Spyderturbo007 19]

I'm experimenting with ripping my 4K disks to store on my unRAID server and then stream to Emby.  I was considering using an NVIDIA Shield, but I don't want to buy on unless it's going to work the way I want it to work.

I compared the rip playing through Emby with the original in my Oppo and they definitely don't look the same.  The rip is lower quality. I thought I would test with a Roku Ultra.  I get some buffering and loading, but I'm betting that's because the Ultra only has a 100Mbps Ethernet connection.

The file I'm testing with is an MKV file with these attributes according to VLC.  To be honest, I don't even know how to tell if I ripped it with HDR.  I suspect that I did since I used MakeMKV.

Anyone know why it doesn't look as good as the Oppo?

This is what Emby says when playing

And here is the "Stats for Nerds"

[Luke 42078]

Hi, Roku doesn't support TrueHD so we have to repackage the video on the fly and convert the audio into a compatible format. Does this answer your question?

[Spyderturbo007 19]

That makes sense. 
 

Any idea why the quality doesn’t match the disk?  I ripped it with MakeMKV so there wasn’t any conversion.  It’s supposed to be a 1:1 rip. 

[speechles 2055]

You do not see the HDR logo like shown above? The HDR Logo only shows for a brief moment when you first start an item and it begins to play.

If you do not see the HDR logo the video stream lacks HDR metadata. For RokuTV that support DolbyVision they will also show the DV logo when appropriate. If the color is 10bit+ this is not HDR in itself. It is just 10bit+ color. You need the HDR metadata to be detected by the Roku to get the effects.

Edited December 6, 2020 by speechles

[Spyderturbo007 19]

There is no HDR Logo in the upper right when it begins to play.  I’m wondering if I’m doing something wrong in MakeMKV when ripping the disk.  
 

is there a way to check the file to see if it has the correct HDR metadata?

[vdatanet 1617]

In media info section, is labeled as HDR? MakeMKV will retain HDR and HDR10+ metadata as they are embedded in the video track.

Edited December 7, 2020 by vdatanet

[rbjtech 5284]

As @Luke has said earlier - ensure you choose a non HD Audio track (AC3/DD) BEFORE you play on the Roku - then it should Direct Play and keep the HDR.

Any form of transcoding/streaming will likely remove the HDR - even if it's just copying the Video stream.

[vdatanet 1617]

3 minutes ago, rbjtech said:

As @Luke has said earlier - ensure you choose a non HD Audio track (AC3/DD) BEFORE you play on the Roku - then it should Direct Play and keep the HDR.

Any form of transcoding/streaming will likely remove the HDR - even if it's just copying the Video stream.

If video stream is copied (just transcoded audio) HDR should be keept.

[rbjtech 5284]

4 minutes ago, vdatanet said:

If video stream is copied (just transcoded audio) HDR should be keept.

ok - if the OP can provide the transcode/ffmpeg log - then we can confirm this in the ffmpeg command line, as by default, I don't believe it does - you need to tell it to use HDR ...

[Spyderturbo007 19]

I'm attaching the ffmpeg log from the file.  It looks like it might be picking up the HDR flag, but I'm no expert at reading these things.

I found "VideoRange" : "HDR" in the log.

Just a side note, let's say the file is ripped correctly, would a Shield play it just like it was the disk?

Thanks!

ffmpeg-remux-a31ee143-3f98-42c4-84f4-cc2d3970078b_1.txt

[vdatanet 1617]

19 minutes ago, Spyderturbo007 said:

I'm attaching the ffmpeg log from the file.  It looks like it might be picking up the HDR flag, but I'm no expert at reading these things.

I found "VideoRange" : "HDR" in the log.

Just a side note, let's say the file is ripped correctly, would a Shield play it just like it was the disk?

Thanks!

ffmpeg-remux-a31ee143-3f98-42c4-84f4-cc2d3970078b_1.txt 58.16 kB · 1 download

I have no experience with Rokus because they are not available in my country, but using Nvidia Shield HDR it is triggered if only audio is converted, although there is a segmentation problem and sometimes green glitches may appear.

[ebr 16184]

Hi.  In the example you posted, we are passing the video through untouched so any quality degradation has to be either in the source, the Roku itself or the connections.

[Spyderturbo007 19]

Is the one I posted HDR?  It doesn't appear on the Roku when I start playing as HDR.  I'm assuming that's the difference. 

[speechles 2055]

5 hours ago, rbjtech said:

Any form of transcoding/streaming will likely remove the HDR - even if it's just copying the Video stream.

Incorrect. A remux or direct stream will retain the HDR on a Roku. HLS with HEVC works just fine on Roku. Only when the video stream is transcoded will you lose the HDR. I have tested this exhaustively.

On Roku the only problem I found is the Roku TV will incorrectly report support for ATMOS when in fact it only has support for DolbyDigital+ in 6 channels NOT 8. If a Roku TV attempts to play an DolbyDigital+ track with 8 channels it will hang your Roku TV. We will correct that problem. This is a firmware bug on Roku TV with firmware 9.4. When Roku corrects that bug we can remove the work-around for Roku TV for ATMOS.

If the Roku TV does NOT display HDR in the top right as the video starts as shown in my screen shots the Roku does not understand the metadata. This is not a fault on Emby. This is a fault of the Roku video player as it interprets the data. We are merely dispatching the stream to the player. What the player does with that stream is where the problem occurs. If you see the same HDR logo I show above when the material begins to play you are seeing HDR on your Roku.

Turn on stats-for-nerds and make sure it isn't a subtitle causing transcoding. That will cause the video to not copy and drop the HDR. As long as the video stream show as (Direct) on the stats-for-nerds you are getting the original video stream unmodified in any way.

 

 

Edited December 7, 2020 by speechles

[rbjtech 5284]

Thanks for the comprehensive reply @speechles

Maybe Roku is different but I have definitely witnessed the HDR flag not being acknowledged on Audio only transcodes on the LG App.  I fully appreciate the video stream should be a 1:1 copy - I get that. 

I don't have this issue any longer as I now run an external receiver (that plays all audio codecs, so I luckily don't transcode anything anymore ..), but to satisfy my curiosity, I'm going to see if I can recreate ... 

[Carlo 4561]

@speechles Any chance you can show the currently being used color space on the SFN display?

[speechles 2055]

11 minutes ago, cayars said:

@speechles Any chance you can show the currently being used color space on the SFN display?

Entirely possible. Also possible to have "Stream Cards" like Android TV has which appear as a row on the detail screen. There is limited room though on these displays so what appears there must be important.

Can also likely get a "transcoding progress" bar to appear on the video player transport bar on the Roku for transcoded progress with blue. Same exact way you see Android TV do this. Same exact way the server display it. Same colors. Same everything. Then you would know by the presence of that blue bar on the Roku that is was transcoding something. Then use stats for nerds to see what exactly is happening.

Edited December 7, 2020 by speechles

[Carlo 4561]

Those would be great.  Thanks for considering this.

[speechles 2055]

There is both ColorSpace and VideoRange. Both of these are required to know HDR versus DolbyVision versus HLG? Maybe both should be there?

[Spyderturbo007 19]

1 hour ago, speechles said:

Incorrect. A remux or direct stream will retain the HDR on a Roku. HLS with HEVC works just fine on Roku. Only when the video stream is transcoded will you lose the HDR. I have tested this exhaustively.

On Roku the only problem I found is the Roku TV will incorrectly report support for ATMOS when in fact it only has support for DolbyDigital+ in 6 channels NOT 8. If a Roku TV attempts to play an DolbyDigital+ track with 8 channels it will hang your Roku TV. We will correct that problem. This is a firmware bug on Roku TV with firmware 9.4. When Roku corrects that bug we can remove the work-around for Roku TV for ATMOS.

If the Roku TV does NOT display HDR in the top right as the video starts as shown in my screen shots the Roku does not understand the metadata. This is not a fault on Emby. This is a fault of the Roku video player as it interprets the data. We are merely dispatching the stream to the player. What the player does with that stream is where the problem occurs. If you see the same HDR logo I show above when the material begins to play you are seeing HDR on your Roku.

Turn on stats-for-nerds and make sure it isn't a subtitle causing transcoding. That will cause the video to not copy and drop the HDR. As long as the video stream show as (Direct) on the stats-for-nerds you are getting the original video stream unmodified in any way.

 

 

It shows as HEVC (Direct) but no HDR logo. 
 

[speechles 2055]

46 minutes ago, Spyderturbo007 said:

It shows as HEVC (Direct) but no HDR logo. 
 

Press HOME twice on the Roku remote. Go to Settings >> TV Picture Settings and make sure the notification is turned on. Sometimes it is not.

The HDR Logo does not appear with stats for nerds. I had to enable stats for nerds first. Then play an HDR item. The Roku if it interprets HDR or DolbyVision metadata and is supported on the Roku device will show the logo when the item first begins to play. The HDR and DolbyVision logos do not show with stats for nerds. I want to make that much clear.

With some HLG encodes the Roku device may not display the HDR logo and is not using the HDR metadata but is displaying in 10bit+. Depends on if that Roku device supports HLG to get support for it.

Edited December 7, 2020 by speechles

[ebr 16184]

4 hours ago, speechles said:

Can also likely get a "transcoding progress" bar to appear on the video player transport bar on the Roku for transcoded progress with blue. Same exact way you see Android TV

That is not transcoding progress.  That is the local player buffer.

[speechles 2055]

1 hour ago, ebr said:

That is not transcoding progress.  That is the local player buffer.

What color is transcoding progress?

The local player buffer isn't exposed on the Roku. The best we have is the transcoding progress can be used against the playback position to give a transport buffer when transcoding. The stats for nerds is already doing all the maths to make it possible.

Edited December 7, 2020 by speechles

[ebr 16184]

15 hours ago, speechles said:

What color is transcoding progress?

The local player buffer isn't exposed on the Roku. The best we have is the transcoding progress can be used against the playback position to give a transport buffer when transcoding. The stats for nerds is already doing all the maths to make it possible.

No color at all.  We don't show that in the player progress anywhere other than on the server dashboard.

[Spyderturbo007 19]

So, I went out and bought a Shield. I was having some stuttering issues with the Roku and apparently it doesn’t support Atmos, Dolby Vision, etc. 

So with the shield, how do I know I’m getting HDR? I don’t see any type of logo appear when playing. However, I do see if on the details section before playing the movie. It says 4K HDR. 
 

Thanks for sticking with me on this one.