I’ve recently changed from a 2019 LG TV to a 2023 Samsung TV and have multiple issues with playback of files, specifically files from UK DVB-T “Freeview” recordings via the DVR. None of these issues were present in the (albeit sluggish) LG app.
Specifically, the HD DVB-T recordings in the UK chop and change between interlaced and progressive. Not just between shows and adverts, but often multiple times during shows. The Samsung TV glitches on each change between progressive and interlaced (in a way the LG did not) and the audio and video become out of sync. The issues is present with Direct Play and Direct Stream.
If I disable both Direct Play and Direct Stream, the server will transcode, but it deinterlaces the signal using frame based deinterlacing, so 1080i50 will be encoded to 1080p25 and any smooth motion (e.g. in sporting events, game shows, soaps, etc) is lost.
Additionally, the audio on the DVB-T transmissions is aac_latm. Which it seems the Samsung cannot play, although the Plex app tries to, and the result is no the audio. So even if the video glitches were not an issue, the audio is broken. I’ve tried to create a custom profile for the “Tizen”, and the logs suggest it is being used, but I can’t get it to force a transcode on MPEGTS streams - the profile seems not to be used. There also doesn’t seem to be a distinction in the profile between aac and aac_latm, so perhaps that “solution” is a red herring anyway.
Finally, I’ve tried to create versions “Optimized for TV”, in many cases this just copies the video stream rather than transcoding, so the glitching interlaced/progressive video issues are still present. Also, the client doesn’t choose these by default, so I need to manually select this anyway (which is just about feasible for me, but not for the family).
I’ve investigated using a wrapper for “Plex Transcode” to inject custom options into the transcoding stage. By changing the deinterlacing from frame to field I can make the server output 1080p50 video which retains the smooth motion, as well as forcing the transcode of aac_latm. I can also inject interlaced flags and transcode the video at 1080i50 - this seems to work too. However, Plex Transcode is used so often, and with so many variations of options, that it’s not really feasible to do this without breaking something else.
Ideally it would be good if
- The Tizen app signals that it cannot play aac_latm to force a transcode.
- An option to retaining interlacing on these files (or an option to use field based deinterlacing to double frame rate). This probably needs a server change, but without it the Tizen app cannot play UK HD DVB-T recordings at full frame rate.
