Streaming 4K HDR video to Roku

[cchasecfi]

Hello.

I am attempting to stream 4K HDR video to a Roku Ultra box. The MKV video file contains 4K HDR video. The video file plays perfectly with VLC Media Player, and is created via MakeMKV with the following attributes:

Length: 02:10:24
Frame width: 3840
Frame height: 2160
Total bitrate: 51884kbps
Frame rate: 23.98 frames/second
Video tracks: HEVC (H265 Main 10@L5.1)
Contains chapters: Yes
Tool name: MakeMKV v1.14.7 win(x64-release)

Audio tracks DTS-HD S24 7.1[Eng], DTS 5.2 [Eng]...
Channels: 8
Audio sample rate 48.000 kHz

Size: 47.2 GB

Item type: Matroska Video File

The Roku device is connected via a wired 1Gb network. The device performance options are set to 4K.
Transcoding is turned off for all devices.

When I attempt to stream the file, the load takes place very quickly, however, only the audio is played. No video is displayed. When I FF the video, the images display in the thumbnails, but after hitting play, the display returns to black with the audio playing.

If I attempt to pre-transcode the file to either MKV or MP4 HEVC, the video displays, however, the color is washed out and faded. Obviously not displaying in HDR. With the MP4 HEVC stream, the video plays for about 5 secs and then displays loading... for about 10 seconds, plays about 5 seconds of video and displays loading... etc. The pre-coded MKV stream, the video plays for about 3 seconds and displays Loading... and freezes. It never comes back. The Mezzmo server shows no activity during this freeze period.

A couple of questions:

1) Why does the pre-transcoded files pause, Loading...? What is Mezzmo doing?

2) Is there no H265 codec transcoding option with the Roku devices?

3) Is the HDR video being sent to the Roku box and Roku is not able to display it or is the video not being sent?

4) Will the transcoding formats MKV and MP4 H264 codecs also pass along the HDR encoding?

I appreciate your help.

[Paul]

When transcoding is turned off and your video has been pre-transcoded, Mezzmo server simply delivers the video data from the video file that your device requests to your device.

Contact us via email at support [at] conceiva [dot] com and we'll provide an updated Roku 4K device profile for you to try.

[cchasecfi]

So requested,

Thanks, Paul

[cchasecfi]

O.K. I downloaded the new profile, Roku 4K, and installed it as instructed. Changed the Media Device entry to the new profile. Verified the Performance attributes:
Turn off transcoding for all connected devices - checked
Maximum bitrate: 800Mbps, (1Gb wired connection)
Maximum video size: Width:3840 Height:2160

1st Streaming attempt:

Direct Stream, (no transcoding), the MakeMKV video file:
Saved as "MakeMKV"
Length:02:10:24
Frame width:3840
Frame Heght:2160
Frame rate:23.98fps
Video tracks: HEVC (H265 Main 10 @L5.1)
Tool name:MakeMKV v1.14.7 win(x64-release)
Item type:Maroska Video File
Size:47.2 GB

Result: Displays :Retrieving - Scale reaches 66% and freezes
Windows Task Manager shows an instance of ffmpeg running using ~45% CPU (is Mezzmo trying to transcode the file?)
Mezzmo Transcoding panel - shows no activity

2nd Streaming attempt:

Pre-Transcode the MakeMKV file using the new, Roku 4K, profile: metroska(-hevc, +aac, +burn.en)
Transcoding time: ~6hrs
Saved as "Mzmo PTC":
Length:1198:08:14 (not a typo)
Frame width:3840
Frame Height:2160
Frame rate:23.98fps
Video tracks:HEVC (H265 Main @L5.0)
Tool name:Lavf57.76.100
Item type:Maroska Video File
Size:75.8 GB

Result: Retrieves in ~10secs, Streams video and audio ok, color is faded, washed out, not HDR
Mezzmo displays the runtime as 19:08
Will not ff beyond ~30min, however plays well beyond 30min and probably contains the entire video

3rd Streaming attempt:

Converted MakeMKV video file using HandBrake:
Conversion time: ~6hrs
Saved as "HandBrake"
Length:02:10:24
Frame width:3840
Frame Height:2160
Frame rate: 23.98
Video tracks: HEVC (H265 Main @l5.0)
Tool name:HandBrake 1.3.0 2019110900
Item type:Maroska Video File
Size:6.50 GB

Result: Retrieves in ~10 secs, Streams video and audio excellent, color deep rich HDR

Summary:

The current work around is to use the HandBrake conversion. Ideally, direct streaming the MakeMKV file would be preferred to avoid the 6hr conversion/pre-transcoding times, also, the more conversions of a video file, the weaker the video quality, (rule of thumb).

[Paul]

Thanks for the excellent testing notes. Can you create a set of logs when streaming each of the above 3 files? That will let us see what's happening between your Roku and Mezzmo server. Turn on logging in Mezzmo (see http://www.mezzmo.com/wiki/doku.php?id=using_logging). Restart your Mezzmo server and repeat your streaming tests. Once completed, stop your Mezzmo server and exit Mezzmo (Windows) app. Zip up all the logs and email them to us at support [at] conceiva [dot] com.

[cchasecfi]

Hi Paul.

Logs are on the way...