[Chromecast Ultra] Augmented profiles need to be updated to support H264 5.1 and 5.2

Plex Players Streaming Devices
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@Volts You’re incorrect because Plex is taking so ■■■■■■■ long (or doesn’t give a ■■■■ for so long) that Google managed to mess up their technical specs page

I’ve already confirmed (and proven) that CC Ultra supports h264 with higher profiles natively. Therefore I’m using a player device that supports them. Do you think I’d post so many details in this thread without doing my homework?

Here’s actual specs cropped out from the tech page a while ago (courtesy of The Wayback Machine / Internet Archive)

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Sorry for the aggressive tone but you irritated me by assuming I provided wrong info after I’ve been trying to reach Plex people for so long. CCU does support these higher bitrate formats

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Including these files? These are very high bitrate/resolution/difficulty for H.264 files.

The Google page has changed a few times over the years. It looks like Google has been really confused about how to format it. :slight_smile: :woman_shrugging:

I see where they added AVC/H.264 Level 4.2 (1080p60). In the table of supported media types, I don’t see that they ever claimed over AVC/H.264 Level 4.2.

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I think I missed where you proved that the CC Ultra supports higher H.264 levels natively. Reading again now.

I’m saying that Google doesn’t currently claim to support higher levels and resolutions of H.264 on the Ultra.

After looking at archive.org, I’m suggesting that they’ve edited that page a bunch of times, and it hasn’t been consistent. Initially the Ultra wasn’t listed with ANY H.264 support, lol.

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It seems to be consistent that in the full table of supported resolutions, even after adding 4.2 and 1080p60, they’ve never claimed to support higher resolutions or level 5+ in H.264.

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I’ve literally just direct-cast the files I pasted mediainfo from in early posts of this thread (H.264 High@5.1 4k) again to re-confirm it supports them perfectly. It still does. Google’s technical page is incorrect right now

Unless you’re saying my android phone is somehow able to live-transcode a 40Mbit H.264 High@5.1 4k stream into something else with absolutely zero hiccups

Can we please stay on topic? Thanks

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I might be confused how this works. I was under the impression that when casting from VLC, VLC itself was capable of transcoding.

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Would actually be cool if phones were able to transcode such videos in real time, wouldn’t it

They aren’t though. Also, I can replicate the same behaviour by casting the exact same High@5.1 files from VLC on a Windows PC. 0.5% CPU usage, 0% GPU usage, 40Mbit network usage. If there was any transcoding involved (hw, sw), it would be clearly visible for content at this framerate

Hope this convinces you that CCU properly supports these higher profiles and bitrates at 4k. Too bad this means that this topic will go back to being dead, courtesy of the dear Plex team

EDIT: Sorry about the constant edits lol

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More evidence for your position that it was once supported:

If Google supported it, and now doesn’t support it … :shrug:. It’s been my experience that every product from Google, except advertising, search, and email, eventually becomes unsupported.

I am curious how it works from VLC, and if there’s magic going on, or - Is it possible to see what the Chromecast is receiving, some sort of info screen? Mostly just curious, since that’s not the use case you care about anyway. (Edit: I can screen mirror with almost 0% CPU, so is that proof? I agree it’s probably sending it directly, maybe remuxing. I’m not actually disagreeing that the Ultra can or can’t play those streams.)

I don’t think it’s reasonable to expect Plex to explicitly support something that Google says isn’t supported. There’s a gap between “support” and “this one works”.

It WOULD be nice to have a “Direct, dammit, and ignore compatibility” option, more generally. Or a “Transcode video to XX, audio to YY” option. That’s sorta the opposite of how Plex works, though.

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Total conjecture: I wonder if they un-supported 5.2 because that can include huge bitrate streams (240mbit/s), and home networks couldn’t reliably support it. Or if it really didn’t work consistently in the devices.

They state support for H.265 Main/Main10 (but not High!), which go up to about 60 mbit/s. And H.264 High 4.2 is about 50mbit/s.

Doesn’t help you at all, of course. :slight_smile:

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It’s my understanding that the way Plex’s profiles work is that the files on the server give a “base”, and then the client sends any “overrides”. Does that match your experience?

This is what I was describing about level editing the files themselves:
https://coolsoft.altervista.org/en/h264leveleditor

That looks like a “dumb” utility; I think it does search and replace instead of understanding the file structure.

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More evidence for your position that it was once supported

That thread is irrelevant, it’s about a regular Chromecast. Thread was made in 2015. CC Ultra got released in November 2016. Time travel is not yet possible, sadly.

You’re speaking of L5.1 in past tense but it’s very much still currently supported as proven

Screen mirroring is different to transcoding

I don’t think it’s reasonable to expect Plex to explicitly support something that Google says isn’t supported

For the nth time Chromecast Ultra supports it, stop putting misleading information here. Someone responsible for the tech spec page has made a mistake and removed those details probably while trying to unify specs

home networks couldn’t reliably support it

802.11ac can easily support such streams. So can the 1GbE port. So can 802.11ax. While ax isn’t supported, CCU does both 5GHz 802.11ac and 1Gbit Ethernet, making the claim to not be able to reliably support them false

This is what I was describing about level editing the files themselves

I could alter these files’ headers, but I’m not interested in doing so. H264@High 4.x doesn’t support 4k resolution so I would be shooting myself in the leg by creating out-of-spec files

Does that match your experience?

In my experience and based off this and other threads Plex just overwrites everything with its default regular Chromecast profile regardless of what Chromecast it is because it’s not easily able to distinguish between Ultra and non-Ultra

TLDR: It’s supported. It’s been supported for a couple of years now. It works using other direct-stream means. Plex still hasn’t fixed their support or given any alternative options

EDIT: I created an Issue on google’s bug tracker so they can address this documentation mistake

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Do you believe that Google supports AVC/H.264 level 5+ on the CC Ultra?

You’ve shown the CC Ultra can play your file, marked as 5.x, when the stream is cast using VLC. It’s not surprising that a device can process some streams that are above its supported level.

That doesn’t mean that higher levels are supported by Google on the CC Ultra, or that the CC Ultra or Plex are behaving incorrectly. They all seem consistent.

Google has edited the Supported Media page repeatedly. They now differentiate that 4.2 is the max supported level on the 3rd Gen and Ultra. I think that’s the definitive answer.

In all of the page edits they’ve never listed a specific media type string for 4K in H.264, which isn’t surprising - it’s an unusual combination. And Google has a history of removing support for higher H.264 levels from other CC devices.

Repeated edits to the page aren’t evidence that level 5+ is supported by Google. It looks more like Google made a mistake or changed their mind. Maybe you have a case for returning & getting a refund on the CC Ultra.

It appears that Plex is obeying what Google has documented. It seems like it would be untenable for Plex to know better than the device manufacturer.

Overriding the labeling in the file IS a terrible hack. 10+ years ago I did it regularly and it worked for me at the time. I’m not sure it’s a worse hack than modifying device profiles. This worked because the Level system is very conservative. I think that’s your situation here today, too.

Some Plex clients give the option to specify a maximum H.264 playback level, but others don’t. Perhaps there are technical and/or policy reasons for this. It would be interesting to hear from Plex. Maybe it’s dependent on the playback engine, or maybe Google doesn’t allow it.

I mentioned home networks because many ARE garbage, not because it’s impossible to stream those bitrates. There’s a huge jump in bitrates from AVC/HEVC 4.x to 5.x. Much larger than for HEVC/H.265. Google may have just wanted to avoid the issue.

I would be pretty annoyed here too. The device might not be able to play all level 5+ streams, but it’s capable of decoding YOUR streams. Google has been inconsistent - which should be expected of them, but is still frustrating. And AVC/H.264 + 4K is valid.

4K in H.264 is relatively rare and has higher resource requirements than 4K in H.265. I don’t think anybody big has ever streamed in that combination. There’s a strong assumption of H.265 (or VP9, or something else) for 4K.

What you have COULD work. But I’m not surprised it doesn’t. I just don’t think there’s any conspiracy about it. I don’t have a dog in this horse race.

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Nice. I’ll bet you a shiny wooden imaginary internet nickel that it’s not (currently) a documentation mistake.

And you might get a response, they actually do seem to follow up on bugs and support requests …

For you, I hope I’m wrong. But it’s more fun to make the bet - and I just made the “dog in a horse race” analogy, so here we go.

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Mate sorry but I gotta say the whole discussion with you is draining, pointless and off-topic. Most of the stuff you’ve claimed has already been disproved and you keep going in and defending Plex (??) for no reason and trying to convince me that I’m seeing things wrong.

You’re not reading what I’m writing or you’re just not pausing to understand what you’re reading.

The only reason this thread is still open is that Plex doesn’t give a crap but even though that’s the case, I won’t just let it die.

I don’t think anybody big has ever streamed in that combination

This is a stupid and irrelevant assumption. Please move on to other threads.

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I appreciate that you want this to work, think it should work, and believe you’ve proven that it does work.

Google’s published support for the Chromecast Ultra is Level 4.2.

I’ve agreed at least once, perhaps twice, and I’ll do so again. It would be nice if Plex provided the ability to disregard Level.

@ChuckPA has commented elsewhere about how device profiles work. This is what I was describing previously. The baseline profile on the PMS can be overridden by the device. In general that’s the expected behavior - the device tells Plex what it supports.

4k playback issue for specific file - #6 by ChuckPa

Per that description, it sounds like the Chromecast Ultra is being queried for what it supports. (Which I believe is Google’s guidance for integrations.)

Edit: Additional comments about how base + capability augmentation operates:

chromcast ultra - chromecast.xml github repo - #8 by duncanbeevers

Similarly, even Emby folks have stated that the Chromecast Ultra reports that it is capable of 4.2:

Chromecast Ultra updated their codec support - General/Windows - Emby Community

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Google Issue Tracker

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Oh well, at least now you’ll also get TrueHD/DTS-HD and DTS-X/Atmos pass through!

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Agreed, and it would be nice if we could refocus on that original goal.

Can we confirm the Chromecast is actually reporting max L4.2?

Can we confirm the profile is being overridden by Plex due to the CC/CCU recognition issue?

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I will see if I can verify this with Google Cast API, haven’t used it before but shouldn’t be too hard

Confirmed by a moderator in this thread that Plex is not able to distinguish what type of CC it’s casting to

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Google devs confirmed that is true and expected:
https://issuetracker.google.com/issues/119760623

This response is also interesting:
https://issuetracker.google.com/issues/36191392

Chromecast Ultra does support 4K streams, but only with HEVC and VP9 video codecs.

They also suggest querying the playback device for capabilities instead of looking up models. There are TVs and other devices that support the Chromecast platform - the MagentaTV Stick was referenced earlier in this thread.

I made a feature request to add the ability to specify a maximum H.264 Level. This would match most other Plex playback apps.

Specify Maximum H.264 Level for Chromecast

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+1’d that feature request, that would get around the issue I believe. Doesn’t seem like they’re willing to do that though? Sigh. Thanks for creating that

The main thing is, CC Ultra direct-streams H.264 2160p High@5.1 (non-HEVC) videos just fine even though Google is trying to claim otherwise in docs and I’m sure we’d like to utilize this capability.

Also, bump.