Server Version#: Synology NAS - 1.20.1.3252
Player Version#: AppleTV - 7.6.1
I have Synology DS918+ NAS ( 1.5 GHz Intel Celeron J3455 Quad-Core, 4G RAM, hardware transcoder) running Plex server which is connected to my AppleTV via a 5Ghz wifi connection. The AppleTV is HDMI’d directly to a 4K TV. I have a Plex Pass for the faster player on the Apple TV to handle RAW Bluray content smoothly and allow the server to use the NAS’s hardware transcoding.
Recently I’ve been experimenting with 4K content. Most of it works smoothly on this setup but there’s a couple which do not. When I play them, they lag and drop frames.
Initially I thought it was a transcoding issue because Plex was reporting that it was transcoding the TrueHD audio. The video is still direct play. On the NAS the CPU is around 15% when doing this transcoding so not taxing it at all. I also checked some other 4K content with TrueHD sound and it was also transcoding the audio, yet the video played smoothly.
So it appears to be a video issue with these two pieces of content. The other 4K content I’ve got runs smoothly without issues. I thought bitrate might be the issue and checked the content. The ones that play smoothly include rates anywhere from 20 to 204Mbps. The ones that stutters are at 80Mbps and 30Mbps. So I’m leaning towards this not being a bitrate issue.
Currently I’m thinking this is something about the encoding but I’m not sure what to look at. Even if I switch to AC3 audio on this content the video still stutters. I could try recoding the content that’s got this problem and see what happens but I’m not sure what settings to try in Handbreak.
Any ideas?
