[MrMagic]

AFAIK, Shield only supports single layer DV profiles, that is profile 5  and 8. So it seems like getting it to play DV 7 at the moment is moot.

But then how come that the profile 7 MKVs trigger DV on our TVs and seem to have the correct colors? Or are you saying that this is some kind of "fake" DV where we are actually looking at HDR10 video without the DV metadata?

[fritsch]

See, that's the pain with blackbox decoders / renders and magic MrMagic. No one can tell you that and you cannot verifiy it. But the good thing is: As long as some green light is shown somewhere, people have the "this is much better" experience in their brain, no matter the picture. Happens for years with audio passthrough ... Perhaps they signal DV, just send "linear constant" metadata and do tonemapping / processing internally :-) - you cannot prove, you cannot know - and when you tune the "contrast" and the colors a little bit more ... subjective impression changes again.

[MrMagic]

See, that's the pain with blackbox decoders / renders and magic MrMagic. No one can tell you that and you cannot verifiy it. But the good thing is: As long as some green light is shown somewhere, people have the "this is much better" experience in their brain, no matter the picture. Happens for years with audio passthrough ... Perhaps they signal DV, just send "linear constant" metadata and do tonemapping / processing internally :-) - you cannot prove, you cannot know - and when you tune the "contrast" and the colors a little bit more ... subjective impression changes again.

Exactly my point

I haven't searched for it yet, but it would be nice to have two sample files that have the same content, where one is encoded with HDR10 and one with DV and where you can actually see a difference between the two. Does anyone know of such a thing?

I think someone mentioned you could check the signal that comes out of the Shield (or any other box) with an HD Fury to see if dynamic metadata is actually being used? If anyone with this kind of setup is reading this thread, maybe we can analyze this a bit more...

[fandangos]

AFAIK, Shield only supports single layer DV profiles, that is profile 5  and 8. So it seems like getting it to play DV 7 at the moment is moot.

But then how come that the profile 7 MKVs trigger DV on our TVs and seem to have the correct colors? Or are you saying that this is some kind of "fake" DV where we are actually looking at HDR10 video without the DV metadata?

Because not all TVs handle Dolby Vision equally.

There are 2 kind of Dolby Vision.
Dolby Vision low latency and Dolby Vision.

In OPPO 203 this is called Dolby Vision Player Led (where the player does the processing) and Dolby Vision TV Led (where the TV does the processing).

The Shield supports both.

Green/purple colors are a symptom of player led DV into a TV led DV.

And what I think is happening is that this can be profile dependent.
Example:
TV can support Dolby Vision profile X as tv led but won't support profile Y.

Vicent Theo (hdtv test) has a nice video showing both formats.

I have a video showing that the Sony 900E that don't support Dolby Vision actually has this feature blocked and do support it if you spoof the EDID. But only as player led. If you do, tv led, it's purple/green screen.

I believe that's the reason why this is setup dependent.

[sk83]

But then how come that the profile 7 MKVs trigger DV on our TVs and seem to have the correct colors? Or are you saying that this is some kind of "fake" DV where we are actually looking at HDR10 video without the DV metadata?

Exactly. I believe the decoder sends a "this is DV" signal to the TV, but the actual data is just HDR10. All profiles except profile 5 have a base signal(SDR or a form of HDR) which will look correct when decoded w/o the DV bits. This is identifed by the BL signal compatibility ID.

See, that's the pain with blackbox decoders / renders and magic MrMagic. No one can tell you that and you cannot verifiy it. But the good thing is: As long as some green light is shown somewhere, people have the "this is much better" experience in their brain, no matter the picture. Happens for years with audio passthrough ... Perhaps they signal DV, just send "linear constant" metadata and do tonemapping / processing internally :-) - you cannot prove, you cannot know - and when you tune the "contrast" and the colors a little bit more ... subjective impression changes again.

 
Yup. The only way to be sure is to analyze the actual HDMI signal with a HDFury device or similar(as long as it doesn't rely on a "digital green light" but the actual signal data)

WRT to Kodi, heres my two cents on how it could handle DV on a high level:

1. Decide if the stream is DV (this info is available in the builds in this thread)
2. Gather info about the DV stream, most importantly profile, level and BL compatibility. (this info is available in the builds in this thread)
3. Check if the devices DV decoder supports the DV profile and level. (possible to check if the profile is supported on the Shield at least, I don't have any other devices)
4. If it does, decode as Dolby Vision(with the correct stream and necessary metadata)
5. If it doesnt, decode stream with decoder according to the BL compatibility.


I have this process somewhat implemented in the build I'm using now, but it is hard-coded for the Shield and not device agnostic(that is, if it's DV7 -> use hevc).
Also, I'm not sure if the actual stream sent to the decoder contains all necessary bits and pieces. The logs which states Dolby Vision profile 0 is what's making me unsure. This is either because the stream is missing something, or bacuse the decoder is missing info about the stream. Maybe some work is needed in the JNI wrapper to expose more functionality. I don't know.

[MrMagic]

Exactly. I believe the decoder sends a "this is DV" signal to the TV, but the actual data is just HDR10. All profiles except profile 5 have a base signal(SDR or a form of HDR) which will look correct when decoded w/o the DV bits. This is identifed by the BL signal compatibility ID.

Thanks for the explanation.

Let me see if I understand correctly. Profile 5 is a "DV stream only" format (single-layer) that only contains a DV encoded video stream. Profile 7 is a dual-layer format where the base layer is (usually) HDR10 and the second layer has the DV metadata. Apparently the Shield can decode profile 5 and send it to the TV correctly. But for profile 7 we cannot be sure the DV metadata is used, so we could be looking at an HDR10 stream that is just labeled as DV?

[sk83]

Thanks for the explanation.

Let me see if I understand correctly. Profile 5 is a "DV stream only" format (single-layer) that only contains a DV encoded video stream. Profile 7 is a dual-layer format where the base layer is (usually) HDR10 and the second layer has the DV metadata. Apparently the Shield can decode profile 5 and send it to the TV correctly. But for profile 7 we cannot be sure the DV metadata is used, so we could be looking at an HDR10 stream that is just labeled as DV?

That is my impression, yes. I also believe it supports profile 8(testing it atm.), which is also single layer, but with a standards compliant base signal. According to the specs, profile 7 only supports HDR base layers. Profile 4 supports only SDR BL, and profile 8 can support both SDR and HDR BL.

[fritsch]

@noggin: any chance to do some measurements?

[fandangos]

Thanks for the explanation.

Let me see if I understand correctly. Profile 5 is a "DV stream only" format (single-layer) that only contains a DV encoded video stream. Profile 7 is a dual-layer format where the base layer is (usually) HDR10 and the second layer has the DV metadata. Apparently the Shield can decode profile 5 and send it to the TV correctly. But for profile 7 we cannot be sure the DV metadata is used, so we could be looking at an HDR10 stream that is just labeled as DV?

That is my impression, yes. I also believe it supports profile 8(testing it atm.), which is also single layer, but with a standards compliant base signal. According to the specs, profile 7 only supports HDR base layers. Profile 4 supports only SDR BL, and profile 8 can support both SDR and HDR BL.

I don't see this stream ID in any mkv remux but I can't say for mp4. 
https://github.com/xbmc/xbmc/commit/7250...6be1bfa602
I made this commit to fix green screen when playing complete UHD BD with menus.

This is part of main kodi now, I don't think it's part of Leia, but it is part of matrix.

@sk83 correct me if I'm wrong but all mkv remux are the same profile, isn't it?
What's the benefit of forcing support for every other?
Is there any content, besides those test samples that do use those profiles?

[hoppel118]

@sk83 correct me if I'm wrong but all mkv remux are the same profile, isn't it?
What's the benefit of forcing support for every other?
Is there any content, besides those test samples that do use those profiles?

If you remux your content with makemkv, you get Profile 7 FEL or Profile 7 MEL.

Yes, you are right. I asked me the same question (again) tonight after a little discussion in the Kodinerds forum: What is the benefit of having support for Profile 4, 5 or 8.1, when we remux or content to P7 FEL or P7 MEL only?

My opinion was that it would be great to have Kodi support for all profiles... But why? Who has mkv dv P4/P5/P81 content?

This profiles are relevant for streaming and tv internal media players. But tv internal media players only support mp4 at the moment.

The mkv support for P4/P5/P8.1 profiles can be done later.

Regards Hoppel

[hoppel118]

If you already read my last post... Sorry, there were some errors I have corrected now.

[quietvoid]

I haven't searched for it yet, but it would be nice to have two sample files that have the same content, where one is encoded with HDR10 and one with DV and where you can actually see a difference between the two. Does anyone know of such a thing?

The Spears & Munsil UHD Benchmark has a lot of differently encoded HDR streams, from 600-10000 nits HDR10 to MEL/FEL Dolby Vision.
I've used it and it's obvious the difference the dynamic metadata makes in the case of the 10k nits version compared to my LG C8's HDR10 curve.

3. Check if the devices DV decoder supports the DV profile and level. (possible to check if the profile is supported on the Shield at least, I don't have any other devices)

Didn't you say already that the Shield doesn't report it supports profile 7? Most devices don't signal their true capabilities.
Making it a strict condition would result in all profile 7 files to fallback to HDR10 only, which isn't really the goal.

The mkv support for P4/P5/P8.1 profiles can be done later.

There really is not much difference between the profiles, the same RPU metadata has to be sent correctly to be used by the decoder.
I don't see a problem in supporting all of them at once, there should not be anything "special" required specifically for each profile.

[Epedemic]

AFAIK, Shield only supports single layer DV profiles, that is profile 5  and 8. So it seems like getting it to play DV 7 at the moment is moot.

But then how come that the profile 7 MKVs trigger DV on our TVs and seem to have the correct colors? Or are you saying that this is some kind of "fake" DV where we are actually looking at HDR10 video without the DV metadata?

I believe DV is working. I also have an E6, hooked up through an Onkyo RZ820, and ALL P7 mkvs work with the first matrix builds from here. I am also positive that DV works, as i see differences (especially noticable with SPR, which is "buggy" on the shield in DV, no matter which player (exoplayer+plex+kodi), with some annyoing "flashing" in scenes with a lot of white, very easy to spot in the first few minutes with the flags against the sky.

[MrMagic]

I believe DV is working. I also have an E6, hooked up through an Onkyo RZ820, and ALL P7 mkvs work with the first matrix builds from here. I am also positive that DV works, as i see differences (especially noticable with SPR, which is "buggy" on the shield in DV, no matter which player (exoplayer+plex+kodi), with some annyoing "flashing" in scenes with a lot of white, very easy to spot in the first few minutes with the flags against the sky.

I had to Google it, but I assume with "SPR" you mean Saving Private Ryan?

[Epedemic]

I believe DV is working. I also have an E6, hooked up through an Onkyo RZ820, and ALL P7 mkvs work with the first matrix builds from here. I am also positive that DV works, as i see differences (especially noticable with SPR, which is "buggy" on the shield in DV, no matter which player (exoplayer+plex+kodi), with some annyoing "flashing" in scenes with a lot of white, very easy to spot in the first few minutes with the flags against the sky.

I had to Google it, but I assume with "SPR" you mean Saving Private Ryan?