Transcode Throttle appears to be broken

[VirtualLlama 5]

When casting a video to Chromecast that requires transcoding Emby doesn't seem to honor the "Enable throttling" setting under Transcoding. Instead of throttling CPU usage once the transcode buffer reaches approximately 2 minutes the video is transcoded at full speed until the entire video has been rendered. The setting works fine when playing a video via the web player in Firefox or the iOS Emby app.

This is using Emby 4.5.1.0 on Debian 10. The Chromecast is a 2nd gen.

I have included a transcode log from the Chromecast where throttling doesn't work and one from Firefox 81.0 where it does work.

embyserver.txt ffmpeg-transcode-aed7a5a4-1fe1-48dc-a674-bcd223c0e71b_1 - Chromcast throttle not working.txt ffmpeg-transcode-dbd4e204-42c5-4b51-83bd-18cfbed3e4c2_1 - web player throttle working.txt

Edited October 3, 2020 by VirtualLlama

[Luke 37100]

Hi @VirtualLlama are you sure about this? It looks like towards the end of the log it did start throttling.

[VirtualLlama 5]

Hi @Luke, sorry I've been an idiot and swapped the names of the log files. The one with the issue is the one called throttle working.

To avoid further confusion here is a new set of log files. When I stopped the playback the transcode buffer was up to approximately 8 minutes and it will just keep going at full speed until all of the movie has been transcoded.

Again, this only appears to be an issue with Chromecast. It works fine when I play a movie in an Emby app or via the web player.

 

 

embyserver.txt ffmpeg-transcode-9860c0d9-fd50-42b3-a435-5483394328b0_1.txt

Edited October 23, 2020 by VirtualLlama

[xsnipuhx 2]

Hi

It looks like throttle transcodes is broken. When a stream starts up that needs transcoding, it does the entire episode/movie all in one go, instead of on demand.

I have attached a dashboard snippet along with a embyserver log.

Any help would be appreciated.

Thanks!

embyserver.txt

Edited October 26, 2020 by xsnipuhx

[Carlo 4330]

Hi, Check to make sure you have "Enable throttling" enabled on the the transcoding menu, advanced settings.

[xsnipuhx 2]

Confirmed its checked.

[Carlo 4330]

Do you have an ffmpeg log associated with that playback?  Can you try playing that again and see if an ffmpeg log is created?

[xsnipuhx 2]

Here's the log for the episode in the picture above.

 

ffmpeg-transcode-5c490fb8-ee8d-4ac9-bbd4-d48723390d9b_1.txt

[Carlo 4330]

Try disabling that feature, save, re-enable and try again.

[xsnipuhx 2]

Done. Had 2 users try streaming and it both still transcodes the entire file at once.

[neik 837]

Due to the throttle being an important feature for me personally, I just tried it myself using ChromeCast and there actually is an issue.
I don't know yet if it's related to ChromeCast or to transcoding in general.
Will try to narrow it down and give feed back.

€dit: @softworkz might have a clue.

Edited October 26, 2020 by neik

[Carlo 4330]

I was just testing this myself and the feature is not working.  When enabled ffmpeg logs still show throttle=off

@softworkz

[Carlo 4330]

BTW, I just played back an HEVC file to chrome to cause a transcode, it's it's not a chromecast issue.

[neik 837]

The throttle not kicking in at all seems to be a transcoding issue though.

While direct streaming it kicks in but the buffer continues to increase second by second at a very slow pace if you let it sit for a bit.

[Happy2Play 8296]

It appears to working fine for me, log and UI show it kicking on and off.

2 hours ago, xsnipuhx said:

Here's the log for the episode in the picture above.

 

ffmpeg-transcode-5c490fb8-ee8d-4ac9-bbd4-d48723390d9b_1.txt 90.39 kB · 1 download

to me this may be a possibly a file issue.

>> ThrottleBySegmentRequest: Latest request position unknown

 

Edited October 26, 2020 by Happy2Play

[xsnipuhx 2]

Just now, Happy2Play said:

It appears to working fine for me, log and UI show it kicking on and off.

to me this may be a file issue.

>> ThrottleBySegmentRequest: Latest request position unknown

 

On multiple files, even ones that have played before without this issue?

[Carlo 4330]

3 of us all having this issue?

[neik 837]

In my opinion this would be too much of a coincidence.

[Happy2Play 8296]

I can see it working in the log, just not in UI for HEVC

12:42:14.024 frame= 3739 fps= 26 q=28.0 size=   17131kB time=00:02:36.07 bitrate= 902.8kbits/s throttle=off speed=1.06x    
>> ThrottleBySegmentRequest: RequestPosition: 00:02:33 - TranscodingPosition: 00:02:36 - ThrottleBuffer: 3s (Treshold: 120s)
12:42:14.611 frame= 3756 fps= 26 q=28.0 size=   17209kB time=00:02:36.88 bitrate= 902.2kbits/s throttle=off speed=1.07x    
12:42:14.890 [segment @ 000001ae72cada80] Opening 'C:\Users\Media\Desktop\Stable\programdata\transcoding-temp\857C0D.m3u8.tmp' for writing
12:42:14.931 SegmentComplete=video:0 Index=51 Start=153.153000 End=156.156000 Duration=3.003000 offset_pts=0 start_pts=153153000 Frames=72 filename=857C0D_51.ts
12:42:14.932 [segment @ 000001ae72cada80] Opening 'C:\Users\Media\Desktop\Stable\programdata\transcoding-temp\857C0D_52.ts.tmp' for writing
12:42:15.118 frame= 3773 fps= 26 q=28.0 size=   17321kB time=00:02:37.65 bitrate= 903.6kbits/s throttle=off speed=1.07x    
12:42:15.654 frame= 3789 fps= 26 q=28.0 size=   17409kB time=00:02:38.37 bitrate= 904.1kbits/s throttle=off speed=1.07x    
>> ThrottleBySegmentRequest: RequestPosition: 00:02:33 - TranscodingPosition: 00:02:38 - ThrottleBuffer: 5s (Treshold: 120s)
12:42:16.134 frame= 3803 fps= 26 q=28.0 size=   17494kB time=00:02:38.92 bitrate= 905.3kbits/s throttle=off speed=1.07x    
12:42:16.718 frame= 3828 fps= 26 q=28.0 size=   17633kB time=00:02:40.05 bitrate= 906.0kbits/s throttle=off speed=1.07x    
12:42:16.878 [segment @ 000001ae72cada80] Opening 'C:\Users\Media\Desktop\Stable\programdata\transcoding-temp\857C0D.m3u8.tmp' for writing
12:42:16.919 SegmentComplete=video:0 Index=52 Start=156.156000 End=159.159000 Duration=3.003000 offset_pts=0 start_pts=156156000 Frames=72 filename=857C0D_52.ts
12:42:16.919 [segment @ 000001ae72cada80] Opening 'C:\Users\Media\Desktop\Stable\programdata\transcoding-temp\857C0D_53.ts.tmp' for writing
12:42:17.196 frame= 3848 fps= 26 q=28.0 size=   17782kB time=00:02:40.82 bitrate= 909.3kbits/s throttle=off speed=1.07x    
12:42:17.707 frame= 3871 fps= 26 q=28.0 size=   17875kB time=00:02:41.83 bitrate= 908.3kbits/s throttle=off speed=1.08x    
>> ThrottleBySegmentRequest: RequestPosition: 00:02:33 - TranscodingPosition: 00:02:41 - ThrottleBuffer: 9s (Treshold: 120s)

But can see it on and off for H264 in the Dashboard.  

So on my Windows system it appears to be working.

[neik 837]

13 minutes ago, Happy2Play said:

So on my Windows system it appears to be working.

This might be the difference, I am on Linux (Ubuntu 20.04.1 LTS, Kernel 5.4.0.48) and latest stable server.

[xsnipuhx 2]

I am on Windows Server. I just prepped my server for a fresh OS. I'll be doing that tonight. I'll report back on if that fixes the issue. Hopefully it also fixes my lifetime Emby premiere key sticking since it appears to disappear and never save.

[Happy2Play 8296]

Everyo ne need to post logs, but the OP log is not reporting position.

 

 

 

Edited October 26, 2020 by Happy2Play

[Carlo 4330]

I take it back.  It is working ok for me.  I jumped the gun.

[Q-Droid 653]

Can confirm. Playback on Chromecast is not throttling when transcoding or direct streaming (remux). The conversion keeps going even if you pause playback.

 

[Happy2Play 8296]

Okay this would appear to be a Chromecast specific issue as I can not reproduce it anywhere else.

Log shows "ThrottleBySegmentRequest: Latest request position unknown"

@Luke stable and beta

Test from iPhone to TV.

Edited October 26, 2020 by Happy2Play