Subtitle Burn-In Improvement Test Build

This does seem to massively improve subtilte burn-in.

However it has ruined performance for tone mapping for me. (Intel Coffelake)

I now can’t smoothly stream a HDR->SDR transcode at all. I reverted back to confirm.

On a given test new build uses 300% cpu (seems to be capped at 50% of available cpu - I have 6 cores) and intel_gpu_top says only using 25-30% video and less render. It will play for a little while then pause and buffer than play for a while and pause and buffer. This happens with subtitles burn in, direct play, transcode, or turned off.

However on 1.40.5.8829-d609c37a9 if subtitles are off it only uses ~ 75% cpu, intel_gpu_top says 70-80% video and 75-85% render everything plays smoothly and fairly quickly develops a fairly solid buffer ahead.

Hmm. Upgraded to test build again and I’m not seeing this problem now. I will do some more testing and see if it recurs. It was very consistent before downgrading and upgrading again. Persisting past reboots of the host.

Now with tonemapping + subtitles I’m seeing about 75% cpu, and in intel_gpu_top 60-70 video, 75-85 render, and 20 video enhance. and playing smoothly. (and is buffering ahead, can do multiple transcodes at live speed)

Testing the latest build using Android TV Plex app. The video never starts if burn-in is set to automatic or only for advanced formats. Just shows the orange circle for a very long time.
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If I choose always burn in. Videos play just fine from the the beginning, but if I fast-forward into the movie it plays 1-2 frames and then the picture freezes. The app on the other hand is not frozen.
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I have not experienced these issues Casting content to the same device. It’s just when I’m using the Plex app on my CCwGTV.
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Any ideas why the Android Plex app is having issues?

It came back! Same symptoms. High cpu usage, low GPU usage, slow transcodes.

Downgrading and upgrading back to test build fixed again. I am assuming it’s going to come back later is there some logs I should grab when it does?

I’ve also been experiencing an issue with SRT subs on Android TV, using a Shield TV Pro. Only the first issue from your list though, where sometimes titles will never start playing. I haven’t had any issues with skipping once I’ve enabled always burn. I will test this on the new build tonight.

@rekh127 next time it happens (before you upgrade) just grab the logs via the troubleshooting section in settings.

@Disgustipated did you have this issue on the same media before upgrading to these builds?

I’m going to test on the latest official version to check if this is a broad issue or just with these builds.

Update
Same issue with the latest official Plex Server build.

Casting works to the same device without issue. Only difference I see in the “NOW PLAYING” is that via the app “Audio” is transcoded to OPUS. And via casting it is AAC.

I’ll dig around the forums related to the Android TV App. This issue is probably not related to these builds specifically.

Latest (8838) Intel 64 Debian build on my i3-N305 Alder Lake-N GPU going great with transcode 4K → 1080p HDR tone mapping on and subtitles burning, “Make my CPU hurt”.

Before it would choke on the Hisense VIDAA TV but now it does not choke it plays fine. Cool thanks.

Anyone experiencing crashes, what Distro + Version + Kernel version (uname -r) are you running on?

My understanding is the algo just changes how light/dark the transcoded images are and stuff like that.

Full setup:

System:

ASUS ROG STRIX B450-F GAMING mobo
Ryzen 5 2600X
Intel Arc a770 (Sparkle)
48GB RAM (2x16 + 2x8)
256SSD (Samsumg 840 PRO)
1TB SSD (WD Blue)
3x3TB rust (HGST something)

Host:

PVE (256GB SSD)
CPU(s) 12 x AMD Ryzen 5 2600X Six-Core Processor (1 Socket)
Kernel Version Linux 6.8.12-1-pve
Boot Mode Legacy BIOS
Manager Version pve-manager/8.2.2/9355359cd7afbae4
Repository Status Proxmox VE updates Production-ready Enterprise repository enabled

LXC:

Debian 12.2-1, unprivileged
6 cores
16GB ram
128GB storage
FUSE, Keyctl

Plex Docker Container:

plexinc/pms-docker:plexpass (tested 8838 by manual update)
/dev/dri passthrough

Ubuntu 24.04 LTS, Kernel 6.8.12
CPU: Intel i7-12700H
GPU: ARC A770M

It was happening before I upgraded to these test builds. But funny enough I tried last night (on the most recent test build here) on an episode that I know I was unable to play a couple of weeks ago and it played fine. It seems sporadic to me.

Also, @FizzBEAUC @CrazyWatermelon afaik Arc GPUs are unsupported so you might be SOL.

Found a workaround that works for me. Check this post: Plex transcoding bug on Android & Android TV - Plex Players - Plex Forum

So, if you have multiple versions of the same media (movie or series). Doesn’t matter what resolution they are. Transcoding will fail if subtitles are enabled. Ensuring there is only 1 version (emptying trash) and transcoding work. This is definitely a bug in the Android App.
Did this on 5-6 movies that never starts when transcoding and they all work now.

I’ll see if I can issue a bug report on this. As I’d like to have multiple versions of certain media.

Update:
Bug reported: [BUG] Plex transcoding with subtitles bug on Android TV - Plex Players / Streaming Devices - Plex Forum

This thread is step 1 on that list, Arc GPUs won’t be officially supported until step 4 at the earliest, along with AMD GPUs.

Well, transcoding does actually work except for the tone mapping issue. fwiw

@FizzBEAUC I am currently working the tonemapping issue, however it will not block this work since it appears unrelated.

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Understood. There are bigger fish to fry.

That seems different from my issue then, I don’t have anything with multiple versions. I also never even see it attempt to start playing, it just sits and does nothing at all. Next time I find something I will have to dig into it more.