Newbie Transcoding Questions

[Zanzi Bizzle]

Hello. I'm pretty new to the world of Jellyfin. I was hoping to set up a media server running off an i5-12600k filled with 4k movies that I could stream to various devices, assuming that it would be able to handle transcoding multiple (6+) streams simultaneously as long as I avoided trying to play HDR on SDR screens. 

After selecting QSV in the hardware acceleration field and enabling hardware decoding/encoding I'm finding that most HEVC media streamed to my phone (Motorola G Power 2022 which I don't believe supports HEVC) has awful pausing and dropped frames unless I manually set the bitrate. I have no idea why playback isn't smoother; my network speed is sufficient, I can see the video is transcoding and none of my CPU, iGPU and RAM are maxed out (though Intel software does seem to indicate way more gpu usage that I would expect from a single transcode.) As long as I select the next bitrate down from it's native value the stream is ok, but if I just leave it on auto I have choppy playback on most HEVC media above 1080p/6Mbps.

I tried derping around with ChatGPT and it said that despite the transcoding process the bitrate is too high for the target device, which kinda checks out since I don't have any of these issues streaming the same or higher quality media to my gaming PC. However a 4k HEVC video at ~21Mbps requires manual adjustment down to 20Mbps to be smooth, whereas a 1080p HEVC at 6.5Mbps may or may not require changing to 6Mbps, and a lower bitrate around 1.5 plays fine without adjustment.. . BUT shouldn't part of the transcoding process involve detemining an acceptable bitrate for the client device? Why would a 4k source video play fine at "20Mbps" while a 1080p can't handle 8 on auto?

It's very confusing to me and some of my friends and family are even less tech-savvy than me so I'd love a solution that doesn't require any manual bitrate adjustments etc to be done by them (and honestly it would be great to build a library in HEVC for better quality/space considerations. It's getting tough to find new releases in 264.)

I've attached a pic of my Playback settings in case that helps (or at least provides a chuckle) as well as some system information captures while trying to playback 4K HEVC media to my phone (~350 dropped frames in short order)

Thank you so much for your time and consideration.

[bitmap]

Can you upload your logs to privatebin.net? Both Jellyfin and ffmpeg logs can be found in Dashboard > Logs. Also, info on how you installed would be useful.

EDIT: Your CPU is Alder Lake, which doesn't support VC-1 or VP8. Doesn't matter for this issue I'd guess, but I would uncheck those. Knowing what OS you're running is also a must.

[Zanzi Bizzle]

Thanks for the reply. Which install information should I provide? Jellyfin Server is running Win11 on a SSD, media is all stored on ancient HDDs (though I did finally just today grab a new NAS drive to shuck.)

I just tried again to play a 4k H.264 video on my phone with the native web player and the playback was terrible, dozens of dropped frames right away. Here is the log.
https://privatebin.net/?109c343ecb6430f5...gVd9iBqo8C
The Integrated player, however, works fine. It says the play method is DirectPlay.
https://privatebin.net/?d0a0dd0006f83fb0...DfqyFh6rsk

1080p HEVC video seems to play fine with the web player.
https://privatebin.net/?052f57e19c5af968...Dezc1h8aQq
But for some reason the video won't even start to play with the Integrated player
https://privatebin.net/?137554756e76a000...bqHrGWDLVf

[TheDreadPirate]

The transcode logs look fine. Transcoding plenty fast.

From what I can find for your phone, the hardware decoders on it are lacking. 1080P30 for HEVC. Same with H264. 1080P30. So 4K is going to need to be transcoded. What is likely happening is that the phone is not accurately reporting its capabilities and isn't triggering a transcode when it should be.

But the Android app has settings to set the maximum allowed resolution.

Settings > Playback > under the Video Quality section check "Limit maximum supported video resolution" and set the drop down above it to 1080P.

If your friends and family have more capable phones, this won't be a concern.

[Zanzi Bizzle]

Thanks for the reply. I had a feeling that may be the case, but then I didn't understand why other streaming apps like Netflix seem to be able to determine an appropriate bitrate.

[TheDreadPirate]

The bit rate isn't the problem. It's the resolution or frame rate or codec level. When selecting a bit rate in Jellyfin, depending on the original codec, supported codecs on the client, etc., Jellyfin will decide on a resolution. In your tests it may be stepping down the resolution once you select a certain bit rate.

[Zanzi Bizzle]

Ah, I see. I'm still learning about all of this so apologies if I use the wrong terms or get confused. Changing the bit rate in the web player just happens to impact the videos a lot. I'm still confused, though. For example..

Spaceballs is H264, 5214kpbs. Playback on auto is awful but as soon as I manually drop the bit rate to 4000kpbs it's perfect.
Doing so changes the video resolution from 3840x2080 to 1280x692 (player dimension is 1600*720)

3 Body Problem is HEVC, 21383kpbp. Same story that when playing on auto its unwatchable but if I decrease the bit rate to 20Mbps (which reduces the video resolution from 3840*2160 to 2560*1440)

I don't understand why I can watch HEVC at 20MPBS but when I try to play H264 automatically at ~5214kpbs there are issues. Its not a huge deal but I'd prefer to move my library to 4k instead of 1080p without my family members who also watch this stuff running into the same issues as me.

[TheDreadPirate]

This may entirely be something with your phone. Motorola chose an odd SoC for the phone and the decoders available in it are extremely lack luster. Especially for a 2022 phone.

If you have access to a different phone model, give things a whirl on that device.

My Pixel 6a has no issues like you've described. So you definitely don't need a super high end phone.

[Zanzi Bizzle]

Ok will do. Thanks again and have a nice day!

[Zanzi Bizzle]

Unfortunately I'm still unable to play these videos back on another device (mind you it's an ancient iPad but that's what I had available to test)

https://privatebin.net/?6b8f498d00dbca64...U19iJcSdg9

https://privatebin.net/?3bb17a0164ab9843...TUKMtcUJcU