Server Version#: 1.20.2.3402
Player Version#: Multiple ATVs on Apple TV 7.6.1 and 1 Roku 6.6.11
I’m running the Linux PMS on Ubuntu 18.04 and I am seeing a weird issue where if I try to stream (and transcode) more than 2 4k videos at a time using hw transcoding on my I9900k I start getting playback errors. It doesn’t just fallback to SW transcoding like I thought it would, it simply fails with a message about error during playback. I found this out when I was running some tests to see how many 4k transcodes I could get going on the quicksync hardware to decide f if I wanted to continue with quicksync or upgrade to something a bit more powerful (like a quadro nvidia card) that has a lot more power for the new NAS I’m building.
So two questions:
Based on the page here: https://support.plex.tv/articles/115002178853-using-hardware-accelerated-streaming it says " * Windows and Linux devices using Intel hardware-accelerated encoding do not have any artificial limit to the number of simultaneous videos." which implies there is no linux quicksync transcode limitation for linux. Is that wrong? Is there really a 2 transcode limitation for quicksync? If so, is it on all intel chips… ie do the newer ones handle more transcodes?
I thought that if there was a limitation it would simply fallback to sw transcoding, which is obviously not ideal, but at least the streams would still transcode and play. Is this a bug?
When the 3rd 4k transcode failed I tried another 1080p video that I new wouldn’t transcode. That ones plays fine, so it seems to simply be an issue when attempting to play a video which requires transcoding when there are currently 2 other hw transcodes going on.
Have others had success transcoding more than 2 4k videos using quicksync HW?
I don’t know where you got your signals crossed but let’s see if we can sort it out.
Nvidia has some drivers which are artificially limited to 2 streams by default.
Quick Sync Video has no artificial limit
I have an i7-7700 and an i7-8809. I’ve run more than 500 Mb/s through them in transcodes (6+ simultaneous transcodes) without video issue. I ran out of players or I ran out of CPU to convert the audio.
This having been said,
Which specific -9xxx CPU do you have? If it’s an i3 or i5, then it stands to reason you’d run out of CPU power with audio or subtitles which would cause playback issues
The Ubuntu machine has an i9-9900K CPU w/64GB ram.
The 4k streams I was running as a test are all the same: 4K (HEVC Main 10 HDR) streams that are around 100Mbps each, but that transcode to something around ~20-40 Mbps. The transcodes all look roughly the same: Plex for Apple TV — Den Playing—14:13 / 53:06 Local (10.0.5.31)—24 Mbps Video 4K (HEVC Main 10 HDR) (hw) 1080P (H264)—Transcode (hw) Audio English (AC3 5.1) Direct Stream
There is no audio or subtitle transcoding, it is all direct streamed AC3 5.1 and subtitles are off.
Based on your comments I tried a quick test starting a transcode with the Amazon 4k Fire TV first and it seems like that device is the one with the problem, not transcoding on the the server. I was able to start two Apple TV 4k transcodes and then a third on my laptop, but even if I try kicking it off on the Amazon 4k player first it fails. It’s an Amazon 4k player, but of course it’s attached to a 1080p TV. It seems like either it it’s trying to stream it natively in 4k but it fails because the TV doesn’t support it, or something else… 1080p streams all work fine there. Also if I attach my 4k roku stick to the same TV the stream starts right up, however it isn’t transcoding on the server, so maybe the roku stick is transcoding down to 1080p?
Either way it definitely seems to be an issue with the “Plex for Android (TV) — Fire TV” device. Any thoughts?
I have an Nvidia Shield (also Android) which will suck down anything I throw at it - direct play).
I would recommend going into the player itself and setting streaming limits (experiment)
“Maximum” / “Original” will ask PMS to send a ‘full strength’ video file.
Roku’s will go at a) whever set for provided b) the display/tv is of equal or higher resolution and capability.
Which brings to the most important point. The players will be your weak point.
A weak player and you’ll think the CPU is the problem.
In contrast, my little ARMv8 test system can stream 80+ Mbps DirectPlay at the Shield and flawlessly. Does that mean an ARMv8 is better than an i9 ? NOPE!
Back to your question/point.
Check the settings on the FireTV. you might need to back it down off defaults for that tv it’s plugged in to. (Not all TV panels can play all codecs and HDR/SDR. There are many 2160p SDR panels on the market being advertised as “UHD” – which is false)
