Server Version#: 1.25.2.5319
Player Version#: 6.9.14.7448-9fa2246a1
When playing back some movies on my new Roku Streaming Stick 4K the video is jerky. It’s like frames are being dropped or something. TV is an LG 55UM7300. PMS is running on Windows 10.
The video is 1080p h264 with 5.1 DCA audio in an mkv with 11.51 Mbps bitrate.
The same file plays fine on both my old Roku Streaming Stick+ and the Plex app built into the TV (WebOS).
I’ve tried fiddling with all sorts of settings in the Roku and the Plex app but nothing helps. There are at least a couple of files that have this issue, however other files work fine that have higher bitrates and the same resolution and audio so I can’t seem to figure out why these files are having issues.
Is it dropping frames mostly around credits sequences or other parts where most of the frame is the same colour? That’s what I’m often getting on Fire TV Cube even though you’d expect it to have less difficulty playing more simple frames. I never have any problems with actual scenes.
No. It happens throughout the entire movie. Even when there’s very little motion. For example just someone on screen talking. Though it seems to be even more noticeable during panning scenes.
I played the file on the Streaming Stick+, the Streaming Stick 4k, and the LG WebOS app.
Streaming Stick+:
Transcoded the container from MKV to MPEGTS.
Direct streamed the h264 1080p video.
Transcoded the audio from DCA 5.1 to AAC Stereo.
LG TV says it is getting 2160p and PCM.
Video is smooth.
LG WebOS Plex app:
Direct played the container as MKV, video as 1080p h264, and audio as DCA 5.1.
LG TV doesn’t say what it’s getting. I think because it’s an internal app.
Video is smooth.
Streaming Stick 4K:
Direct played the container as MKV, video as 1080p h264, and audio as DCA 5.1.
LG TV says it is getting 2160p and PCM.
Video is choppy.
I’m not sure why the Stick+ is transcoding down to stereo. I guess although it supports Dolby Digital and DTS it doesn’t support 5.1?
Anyway, I’m really at a loss as to what’s going on here and how to fix it.
I did some more investigation and noticed that the jerky video only seems to occur if the video is direct played AND the file has DTS audio AND the container is MKV.
If the video is direct streamed and has DTS audio then Plex changes the container to MPEGTS and the jerky video does not occur.
I came to this conclusion after testing various files with different audio but confirmed it when I found a single file that had both a DTS and TrueHD audio stream.
Playback 1:
Manually select the TrueHD audio stream
Plex direct plays the video
Plex direct plays the TrueHD audio
Plex direct plays via the MKV container
Video is smooth
Playback 2:
Set direct play to disabled
Manually select the DTS audio stream
Plex direct streams the video
Plex direct streams the DTS audio
Plex converts the container from MKV to MPEGTS
Video is smooth
Playback 3:
Set direct play to auto
Manually select the DTS audio stream
Plex direct plays the video
Plex direct plays the DTS audio
Plex direct plays via the MKV container
Video is poor / stuttery / jerky
So direct playing MKV files with DTS audio on Roku seems to mess up the video.
Looks like it is a bug and it’s been around for a while. Based on my new discoveries I found this thread: Movies with DTS are stuttering on latest Roku Ultra 2020 It says Roku Ultra 2020 but others have commented about it happening on the Streaming Stick 4K.
