The Roku will still directly play the video but the plex server will transcode the audio. DTS stereo is transcoded to AAC stereo by the Plex Server. The Plex Server will transcode AAC, DTS, and EAC3 5.1 audio down to AC3 5.1. S/W Version: 10.0.0 build 4185-C2 (problem was present in at least 1 prior version) Half of my video collection are no longer viewable as a result of this so I'd be happy to provide any additional info if it'll help with the fix. My guess is Roku changed some HDR detection defaults with the recent software releases where if it is not sure whether a video track is SDR or HDR, it will pass it as HDR. The working video track had these 3 additional fields while the non-working version are missing these:Ĭhanging the audio encoding (EAC3, AAC, DTS, etc.) doesn't seem to make any difference The one with BT.709 played back with correct colors while the non BT.709 video had the saturation/contrast as reported by OP. I tested this by transcoding a SDR video with without setting color range to BT.709 and then transcoding the exact same video with BT.709 setting. It seems when a video file is encoded in HEVC, but the color range standard is not specified in the video track, Roku will NOW default to HDR even if the video is SDR. Here are the two threads about this over at the Plex having the exact same issue about 2 software updates ago specifically streaming from Plex (Direct Play, no on-the-fly transcoding) After a lot of testing with videos that I know used to work, I think I identified the cause. I currently have a ticket with Roku support about this issue and a Plex dev stated previously he was going to report this issue to Roku also. When I extracted the videos from the MKV using FFmpeg and put the videos into an MP4 container, the videos did not suffer from the “always-on” HDR issue, despite still being HEVC/SDR. The 8-bit video put into both an HEVC 8-bit and 10-bit MKV container suffer from the “always-on HDR” issue. I used FFmpeg apt repo installed on Ubuntu 20.10 to convert the video from AVC shot on an iPhone 6S to HEVC. To create test/example videos that are easy to share I used a 25-second kitten video my wife took. I have seen the error also with mp4 files however, those are usually mp4 files developed using various tools designed for creating mkv files then the video is extracted from an mkv and put into an mp4 container.

Any time someone tries to play an HEVC/SDR mkv on the 4800x, HDR will stay on continuously, distorting the picture. HEVC/SDR mkv files have not been working correctly on the 4800x for some time now.

Plex roku