Could use some general ideas/advice: Transcoding barely works; untranscoded causes buffering

For help and support with Universal Media Server in general
Forum rules
Please make sure you follow the Problem Reporting Guidelines before posting if you want a reply
Post Reply
Posts: 16
Joined: Mon Jan 26, 2015 8:44 pm

Could use some general ideas/advice: Transcoding barely works; untranscoded causes buffering

Post by Henduluin » Sat Jan 18, 2020 11:39 pm

I could really use some help here. I've been using UMS (and its predecessor) for nearly a decade now, but I'm currently having so many issues I'm tempted to just chuck in favor of simply getting an external storage device so I don't have to bother anymore.

Up until a few months ago, I'd been streaming media to my PS4. This worked relatively well, but any kind of pausing or fast-forwarding/rewinding caused the file to crash after a minute or two.

Then my old TV died. I got myself a LG 4K OLED55B8 and promptly found out you don't quite get the full color depth or image quality if you stream via the PS4, so I switched to streaming to my TV directly.

This wasn't anywhere near as successful as I'd hoped.

FFmpeg doesn't work for half the videos. For those it does, pausing causes crashes much like on the PS4 and forwarding/rewinding does not function at all. It just causes the video to start anew from the very beginning.

MEncoder and Avisynth don't even try.

Figuring my PC was more than up to the task, I went with the 'No transcoding' option, which works fine... except that subtitles lose any and all settings attached to them, often resulting in an unreadable mess.

Then last week I found out that trying to stream 4K untranscoded is a lost cause because my TV apparently has the cheapest LAN port imaginable, resulting in *very* frequent buffering. But when I try to transcode, not a single option works. Going back to streaming over the PS4 works, but then I lose out on image quality again.

For reference, my PC has a Ryzen R9 3900x, 32GB DDR4-3600 RAM, Geforce 2070 Super and runs off of an Nvme SSD. I *highly* doubt the problems are on that end.

Is there anything I can try to salvage this, or am I better off just shelving out 50 bucks for an external HD? I have, to my knowledge, tried tweaking pretty much every setting in the default UI. Only thing I haven't tried is editing the setting files directly, which I believe is possible from what I've glanced from other posts.

tl;dr: Transcoding is a broken mess, untranscoded streaming results in buffering @ 4K, along with messy subtitles. Halp.

Attached is a zip with logs that should show the issues mentioned above, barring the buffering.

Thanks for any and all advice you can give.
(173.39 KiB) Downloaded 102 times

Posts: 1829
Joined: Tue Jun 09, 2015 5:57 pm

Re: Could use some general ideas/advice: Transcoding barely works; untranscoded causes buffering

Post by Nadahar » Sun Jan 19, 2020 4:58 am

It sounds to me like you have several issues all acting together to make a complete mess. Looking in your log I see nothing obvious, except for the fact that your renderer keeps disconnecting while UMS is sending. That is usually caused by UMS not sending according to the renderer's expectations (it can be any kind of headers or other details that's not as expected, or that the content itself isn't what it wants). As I see it, this is most likely caused by either: UMS isn't following DLNA appropriately (which it isn't) or the transcoding output isn't following the media specs well enough for it.

I see that you use tsMuxeR at least some times, and it's well known to not follow the standards properly so that the output is "only acceptable to some renderers". I would start by disabling tsMuxeR alltogether.

It's also very likely that the renderer configuration isn't correct for your TV. The renderer configuration describes to UMS what the capabilites of your renderer are, and if it doesn't match the true capabilities, problems will arise. This usually results in varying results for different file/codec types. From your log, I can only find MKVs. Do you have the same problems with TS, MP4 etc?

The "larger" problem however is the bandwidth issue. If your TV can't handle the bandwidth of certain files, they have made some terrible choices. I know they often use 100 Mbps network interfaces because they are cheaper, and IF the use 1 Gbps they will generally make sure it's mentioned "everywhere". If you don't find anything particular about the network speed, it's probably 100 Mbps. Still, I would think that most files should play at that speed as long as the rest of your network is performing as it should (the switch primarily). I assume there's no wireless involved, that the signal goes from UMS to the TV exclusively on wire? I can however see how some very "high bandwidth" files won't fit there. The problem is that, by transcoding it so that it can actually "fit" through a 100 Mbps connection, you WILL have quality loss. There's no way around it, so I doubt that the result will be any better than simply using the PS4 anyway. Another thing is how well UMS "tunes" the transcoding, ideally you'd want it to tune the transcoding so that it use almost all the available bandwidth without saturating it. There is no "sophisticated" code in UMS doing such a thing though, so you'd probably end up with the transcoding either outputting a too high (causing lag/buffering) or too low (bad quality) stream. Since there are so many different devices, network setups and in general "unknown bottlenecks", there's no way to make this very sophisticated, so the choices that are being made are quite "crude". I'm not saying it couldn't be done better that it currently is, but doing it really well for all circumstances is at the very least a huge challenge.

Without solving the fundamental "bandwidth" issue, I'm not sure I would spend too much time on the other stuff. I don't know if it's possible to attach another NIC (or even an AC wireless NIC) to the TV. If so, that might be the best solution, but I doubt it would be cheaper than putting a harddrive in the TV. It would be more convenient than having to transfer everything to said harddrive though.

Posts: 16
Joined: Mon Jan 26, 2015 8:44 pm

Re: Could use some general ideas/advice: Transcoding barely works; untranscoded causes buffering

Post by Henduluin » Sat Feb 01, 2020 3:56 am

Thanks for the advice, and apologies for the late reply.

I've tried several more things, such as disabling tsMuxer as you suggested, but the tl;dr is that I basically gave up and just got myself a big ol' HDMI cable that I roll across the floor every now and then. It's by far the cheapest option, and getting 4K to work any other way just wasn't worth the headache.

Post Reply