HW acceleration overriding max. bitrate

[M_L 0]

Hello,

I was fighting with stuttering videos (over the internet) since the beginning of my emby time, and now I found a solution for it, better say I found the bug.
The bug lays within the Hardware acceleration option. Having it on auto causes stuttering. Selecting Intel Quick Sync and selecting a server wide or client bitrate limit makes it run flawless. I looked on the bandwith usage and the point is, that on Auto it doesn't care what bitrate limit you set, with Intel Quick Sync it uses only as much as set (on the server and/or client).

For me that's the solution, if you want to kill the bug I can give you some more insights.
Best greetings
Martin
 

[Luke 42077]

Hi, welcome. When hardware acceleration is set to auto, then there is currently no hardware acceleration. So whatever you're suggesting here isn't related to quick sync at all.

[M_L 0]

I can set hardware acceleration to auto or Intel Quick Sync. 

And, when settings it to auto, the bandwith is higher than defined in the max bandwith setting, which causes stuttering. 
The name "auto" tells me that emby decides whether it uses hardware or not, so it's unknown what it really does. 

Edited February 4, 2016 by M_L

[Luke 42077]

I think you are trying to tell us where you think the problem is rather than just telling us about the problem so that we can handle finding the solution. So let's start from the beginning. Please describe in detail the issue you're having, and also see how to report a problem for additional info that should be attached. Thanks.

[M_L 0]

Issue: Some Matroska movie files are stuttering when there are fast scenes in the movie.
I uploaded three logs, one for the server and two for the transcode. Both transcode log shows the same movie played, but in one of them HW=Auto and in the other HW=IntelQuickSync.
With best greetings
M_L 
 

Emby_Server-Log.txt

Emby_Transcode_HW-Intel.txt

Emby_Transcode_HW-Auto.txt

[Luke 42077]

As a test, try disabling transcoding throttling (on the same screen). Just curious if that might make a difference.

Without quick sync your server is transcoding just barely fast enough so that might explain it.

 

Also, what app are you playing from? It appears you set a custom bitrate. Try setting the bitrate to Auto.

[M_L 0]

Disabling throttling increases the transcoding speed as expected (see log).
Bitrate: Inside the video player no limit set (50mbps), In device settings no bitrate set (50mbps), Server wide limit 5mbps. But no matter where I change the bitrate limit, it doesn't care while HW is on auto. Setting bitrate on auto everywhere with throttling off increases the trancoding incredibly, better say it gives me the original bitrate, but it still sutters.
App: webclient, Chrome, Wifi connection, download 50mbit
Server: Core I5 Ivy, Windows 10, 8Mbits Upload (which is the bottleneck, and so bitrates > 8mbps wil stutter.)
I can post more later,... have to go now
Thanks for your help! 

 

Emby_Transcode_HW-Auto_Throttling-Off.txt

Emby_Transcode_HW-Auto_Throttling-Off_Bitrate-Auto.txt

[Luke 42077]

Yes it does care, sorry to contradict you. Both of these logs look fine to me. Maybe the issue is not encoding speed but rather network delivery to the device.  the automatic bitrate is usually pretty good about picking a reliable value, but it's not perfect. maybe you could try setting a bitrate of 1mbps, something low, and then see how that goes.

[M_L 0]

Here are the logs made with 1, 2 and 3mbps server wide bitrate limit, but the real bitrate is much higher.
 

HW-Auto_Throttling-On_Server-Bitrate-3mbps.txt

HW-Auto_Throttling-On_Server-Bitrate-2mbps.txt

HW-Auto_Throttling-On_Server-Bitrate-1mbps.txt

[Luke 42077]

Ok, thank you. What i see happening here is we're requesting a bitrate with ffmpeg, but the output is much higher. I will adjust the command lines for the next release. Thanks for the info.

[M_L 0]

That would be great! Thank you

[lal 4]

That would be great! Thank you

 

Hi - This bug is fixed and in stable, Luke confirmed: http://emby.media/community/index.php?/topic/29587-external-stream-freezing-issues/?p=301795

 

I'm interested in finding out if it resolved your issue?

I have a similar issue that might be related to this bug, and retesting today with 3.0.5871.0 didn't fix it for me.

[Luke 42077]

Your topic is unrelated, sorry.