Direct Play for 4k MKV File Will Not Play on Roku

[dyecast 6]

I've tried manual bandwidth settings + auto on the Roku.  NOTHING.

The Roku and synology on a Gigabit switch 2.1 feet from each other.  NO meaningful LAN traffic.

SOOOOOO tiresome.  Please help.  This same file plays on my Brave brower, iPad and iPhone WITHOUT any issue.

 

ffmpeg-transcode-440ec708-a00c-41e4-9d90-2c29aac047a0_1.txt embyserver.txt ffmpeg-transcode-bce41913-9f3e-418b-ba42-d13c6ce4be12_1.txt

Edited February 3, 2025 by dyecast

[Luke 42077]

Hi, what exactly happens?

[dyecast 6]

I start to play the video on Roku.

After several minutes, nothing is still happening on the TV. See TV screenshot.

I took a phone screenshot of the progress at one point.  No transcoding.  Should be playing and yet here we are.

Edited February 3, 2025 by dyecast

[speechles 2055]

Does any loading spinner ever appear? In your screenshot I do not see one present. I am assume this is a TCL Roku TV? Or is this a Roku stick or set top box attached to the TV?

You can also raise the video quality to as high as it goes in the Emby Roku settings. On the Emby Roku homescreen press the star/asterisk button on the remote .. or .. navigate to the cog/gear at the top of the screen. At the top of the playback settings is video quality. The Emby Roku app has its own video quality setting different than the web app. In case you did not know.

Then once you raise it to the maximum try to play the item again. If it hangs and just never progresses it could be something in the MKV header causing the Roku to stall playback. The video player will normally throw an error and close the player and we can then attempt with different methods of playback. But in the rare instance it hangs it usually has to do with something funny/incorrect in the header of the MKV.

If you use MKVToolNix GUI and remux that file copying everything the same but just recreating the new header that might allow it to play. Let us know what happens.

 

Edited February 3, 2025 by speechles

[Carlo 4560]

On 2/2/2025 at 7:18 PM, dyecast said:

The Roku and synology on a Gigabit switch 2.1 feet from each other.  NO meaningful LAN traffic.

SOOOOOO tiresome.  Please help.  This same file plays on my Brave brower, iPad and iPhone WITHOUT any issue.

Hi @dyecast

I've seen this movie being used in different messages posted for other clients.
Just curious, why are you intentionally playing back high bitrate 4K HDR content on clients that aren't 4K HDR or on screens so small that 4K would hardly be of any benefit?
The reason I ask is because you end up forcing a real-time transcode that's converting HDS to SDR, scaling from 4K to 1080 or 720 and likely having to convert the audio as well.

A more typical way to handle this is have a normal SDR version in 720 or 1080 and then the 4K version.  With two versions of the movie grouped together they will appear as the same movie in the UI with a selection of version to use.

So in many of the cases where playback is a problem and transcoding is taking place, it could likely have used the 1080 version. If the 4K version couldn't direct play at least the video portion and transcoding needs to happen the 1080 version becomes much easier on resources to use. This assumes each client has been optimized to allow the maximum bitrate iit can handle.

Depending on use, this can become an important point because looking at your logs, your NAS is likely only going to be able to transcode 1 4K HDR file like this at a time and maybe one other normal 1080 file.  I know this info from looking at your log seeing "speed=1.44x" while transcoding this file.  That means it was transcoding the video at 1.44 times real time speed. In order to be able to transcode two streams like this the speed would need to be 2x or better.

If the system is just for your own use the number of transcoders doesn't matter, but if sharing with family and friends then you need to employ methods to reduce needing transcodes like having multiple versions of media available, making sure you have common 2 channel stereo tracks in media to avoid audio transcoding, as well as removing/replacing hard coded subtitles. The NAS only has so many resources available for transcoding and beyond that you need to think about more powerful server using standalone GPUs for transcoding.

 

[Happy2Play 9780]

Isn't the Roku defaulted to 40Mbps?

&VideoBitrate=40680000&AudioBitrate=320000

&TranscodeReasons=ContainerBitrateExceedsLimit

So users are required to set to higher playback quality for all content over 40Mbps.

But yes we know these limit can be exceeded but from a dev standpoint should be the baseline.

Edited February 7, 2025 by Happy2Play

[dyecast 6]

9 hours ago, Happy2Play said:

Isn't the Roku defaulted to 40Mbps?

&VideoBitrate=40680000&AudioBitrate=320000

&TranscodeReasons=ContainerBitrateExceedsLimit

So users are required to set to higher playback quality for all content over 40Mbps.

But yes we know these limit can be exceeded but from a dev standpoint should be the baseline.

This was incredibly helpful.  I foolishly assumed the EMBY app would be limited based on these specs.  I set the Emby app on Roku to 40 Mbps.  No change.

I then set it to 35 Mbps.  FIXED.

Can we get a bug in for the Emby App in Roku so that it reflects these limits?

 

 

[Luke 42077]

43 minutes ago, dyecast said:

This was incredibly helpful.  I foolishly assumed the EMBY app would be limited based on these specs.  I set the Emby app on Roku to 40 Mbps.  No change.

I then set it to 35 Mbps.  FIXED.

Can we get a bug in for the Emby App in Roku so that it reflects these limits?

 

 

Hi, what do you mean by no change? what do you mean by fixed?

[dyecast 6]

11 minutes ago, Luke said:

Hi, what do you mean by no change? what do you mean by fixed?

I changed the Video Playback setting in the Emby App on my Roku 4k Box to 4k @ 40Mbps.
The results were the same - video hangs at the splash screen.

I then changed the Video Playback setting in the Emby App on my Roku 4k box to 4k@ 35Mbps.

All 4k videos that would NOT play on uniquely on the Roku's Emby app will now play.  I can also see in the Emby Server Admin Control Panel that Emby is transcoding them down once it was set to 35Mbps inside the Emby-Roku app.  It would NOT transcode at 40Mbps.

It's weird that the Emby app on Roku would have playback setting that the appliance cannot handle.

Edited February 8, 2025 by dyecast

[Happy2Play 9780]

10 hours ago, dyecast said:

I changed the Video Playback setting in the Emby App on my Roku 4k Box to 4k @ 40Mbps.
The results were the same - video hangs at the splash screen.

I then changed the Video Playback setting in the Emby App on my Roku 4k box to 4k@ 35Mbps.

All 4k videos that would NOT play on uniquely on the Roku's Emby app will now play.  I can also see in the Emby Server Admin Control Panel that Emby is transcoding them down once it was set to 35Mbps inside the Emby-Roku app.  It would NOT transcode at 40Mbps.

It's weird that the Emby app on Roku would have playback setting that the appliance cannot handle.

Well technically locally you should increase the value to probably max so your media will direct play.  Or at least higher than 60Mbps per your examples.

But to a point it could be the media itself (DOVI) and transcoding but did not really break it down looking at all the video info.

Edited February 8, 2025 by Happy2Play

[speechles 2055]

12 hours ago, dyecast said:

I then changed the Video Playback setting in the Emby App on my Roku 4k box to 4k@ 35Mbps.

All 4k videos that would NOT play on uniquely on the Roku's Emby app will now play.  I can also see in the Emby Server Admin Control Panel that Emby is transcoding them down once it was set to 35Mbps inside the Emby-Roku app.  It would NOT transcode at 40Mbps.

Can we see an ffmpeg log created from when you changed it to 35Mbps? That would give us clues about why the item had problems playing back directly.

If it hangs with direct play it is something about the media that particular Roku does not like. When you transcode it creates an m3u8 and uses ffmpeg to convert the video stream to h264 and a lower bitrate. Transcoding will create a Roku friendly version but will consume cpu/gpu power and is not as efficient as direct play.

Seeing the ffmpeg log will show us the original media specs which should give us some insight into why this wouldn't play directly.

NOTE: It is odd seeing MP3 audio with a 4K HEVC video. Almost like it is an encoding mistake. Why didn't they use AAC Stereo? Why not AC3 surround? Why go with the primitive mp3? This can lead to other mistakes such as mastering the video stream into non-compliance with standards. Or putting gibberish into the MKV header like some encoding programs will do with "global tags". All of which cause the Roku to have problems direct playing the file.

Edited February 8, 2025 by speechles