Emby transcodes if external display plugged in

[mobamoba 12]

The gist of this bug is as follows: a file that direct plays in Kodi and direct streams (I think that's what you call it when it only transcodes audio) when played in Firefox, transcodes everything when I plug in an external display. The second I unplug, it goes back to direct playing. Exact same file, exact same computer, exact same playback applications, only difference is whether or not an external display is attached.

 

Additionally, Emby grinds to a complete halt when the external display is plugged in. To be clear, thesystem Emby is on does NOT grind to a halt - ffmpeg is using maybe 10% of the CPU - so this is not a slow system transcoding issue. It's Emby that stops. For example, the dashboard page won't reload, just hangs forever. And, while the video - which shouldn't be transcoding at all - is transcoding at 74fps, it's stuttering and not playing on both Firefox and Kodi (tested separately) when the external display is attached. When I unplug, it all goes back to normal.

 

I don't know why plugging my laptop into an external monitor would throw Emby into such a tailspin, but that's what happened and wanted to report it.

 

Using the most recent stable version of Emby.

 

ETA: Log attached.

emby.txt

Edited May 4, 2018 by mobamoba

[Luke 37254]

What if you stop playing first, plug in the display, and then start a video?

[mobamoba 12]

That's what I initially did - same problem. I initially played it in Firefox on my laptop, paused it, plugged in the display (tried mirrored and extended), had the transcoding thing where Emby totally clogged up, closed out my Firefox tab, opened a new Firefox window and tried to play and had the "it's now transcoding" problem. I then shut down Firefox, opened Kodi, let it connect and same thing. After unplugging the display, I paused Kodi, hit play again, all fine no transcoding. Same thing in Firefox

[Luke 37254]

And the ffmpeg log?

[mobamoba 12]

Here you go.

emby transcode.txt

[Luke 37254]

This is an mkv which firefox doesn't support, therefore some ffmpeg involvement is required. Ordinarily it should just remux, but it looks like it's doing a full transcode due to your in-app quality setting.

[mobamoba 12]

I have no in-app quality settings that I'm aware of - everything is default.

 

And it didn't do a full transcode in Firefox when I unplugged the external monitor. And, of course, Kodi can play everything so doesn't require transcoding regardless yet Emby transcoded when Kodi was plugged into the external monitor as well. Is that not in the log?

 

And the transcoding also doesn't explain why Emby (and only Emby) completely froze (the Dashboard page as I mentioned above). When I unplugged the external monitor, Emby worked again as normal. As I mentioned, the transcoding was only using 10% of my CPU so that wasn't the cause of Emby choking either.

 

Would it be helpful to try again using debug logging?

[Luke 37254]

Try checking your in app quality setting in Firefox. What is that set to?

[mobamoba 12]

Sorry I'm not sure what you mean. What Firefox app settings are you referring to?

[Luke 37254]

Click your user icon in the top right.

[mobamoba 12]

I've never touched that section (as you can tell since I had no idea what it was ). Everything is set to defaults, all Auto.

[Luke 37254]

Is this internal in your own network?

[mobamoba 12]

No I'm accessing Emby from out of state.

 

I did a test and have attached the logs. I played a file on my laptop in a Firefox tab. I then restarted the Emby server, plugged my laptop into an external display, opened a Firefox tab and played the exact same file. So same file, same browser, same computer, same network, same everything except in the second test I ran an HDMI cable from my laptop to a monitor. As you can see, without an external display attached, Emby simply remuxes the file. With an external display attached, Emby does a full transcode. This shouldn't be happening I don't think since literally everything is the same except the external display connection.

emby log firefox on laptop.txt

ffpmeg log firefox on laptop.txt

emby log firefox with external display.txt

ffmpeg log firefox with external display.txt

[Luke 37254]

I really can't think of anything here as the web app doesn't even have any awareness about the external display.

 

You're saying the quality is on Auto, you could also try specifying the quality to a high enough value that will avoid the transcoding, while making sure that the network connection can handle it.

[Luke 37254]

The stream urls differ only in bitrate requested:

videos/968dfb2adc95898ad15b6db0357dd11f/hls1/main/0.ts?DeviceId=1ae064617a0f543a9bdf142fee03e76f103a8c65&MediaSourceId=968dfb2adc95898ad15b6db0357dd11f&VideoCodec=h264&AudioCodec=aac&AudioStreamIndex=1&VideoBitrate=55616000&AudioBitrate=384000&PlaySessionId=13056dfe0a22480689d94e9a959670a9&api_key=1be586bbc78646158f7df2795aae2168&TranscodingMaxAudioChannels=2&RequireAvc=true&Tag=30245e42a586046dbbdff23572d4c267&SegmentContainer=ts&MinSegments=1&BreakOnNonKeyFrames=True&h264-profile=high,main,baseline,constrainedbaseline&h264-level=51&h264-deinterlace=true
videos/968dfb2adc95898ad15b6db0357dd11f/hls1/main/0.ts?DeviceId=1ae064617a0f543a9bdf142fee03e76f103a8c65&MediaSourceId=968dfb2adc95898ad15b6db0357dd11f&VideoCodec=h264&AudioCodec=aac&AudioStreamIndex=1&VideoBitrate=3138013&AudioBitrate=384000&PlaySessionId=2bd195494c4e419a854d1082fb344ccf&api_key=1be586bbc78646158f7df2795aae2168&TranscodingMaxAudioChannels=2&RequireAvc=true&Tag=30245e42a586046dbbdff23572d4c267&SegmentContainer=ts&MinSegments=1&BreakOnNonKeyFrames=True&h264-profile=high,main,baseline,constrainedbaseline&h264-level=51&h264-deinterlace=true

Try checking the quality setting while the external display is plugged in.

[mastrmind11 717]

Everything is the same except the HDMI connection.  There's might be something jacked with what the external display is reporting and/or the HDCP handshake. Also, this:

 

Laptop as display:

Stream mapping:
  Stream #0:0 -> #0:0 (copy)
  Stream #0:1 -> #0:1 (ac3 (native) -> aac (native))

External display:

Stream mapping:
  Stream #0:0 -> #0:0 (h264 (h264_cuvid) -> h264 (h264_nvenc))
  Stream #0:1 -> #0:1 (ac3 (native) -> aac (native))

And also this:

2018-05-04 12:57:46.718 Info App: Bitrate exceeds DirectStream limit: media bitrate: 3378797, max bitrate: 1500000

Disable hardware acceleration if it's enabled, and adjust your bitrate setting in the app to something higher and report back.

[mobamoba 12]

I have no DirectStream limit unless that's the default limit. I've literally never changed any of that stuff from whatever's there default. And it doesn't even make sense. It's streaming from and to the exact same server and laptop on the exact same networks mere minutes apart both times, and it's not as if the internet connection at either or both ends suddenly drastically dropped due to plugging in an external display. And it's not as if plugging in an external display somehow strips Firefox of it's ability to playback an h264 video file that now must be transcoded into another h264 video file.

 

In other words, Emby is mistakenly detecting some hardware or bandwidth change when the external display is plugged in though what that would be or how Emby is getting that information or why it's doing it I have no idea.

Edited May 4, 2018 by mobamoba

[Luke 37254]

 

 

 mistakenly detecting some hardware

The web app has no hardware detection. But yes we do use browser api's for bandwidth so maybe there is a defect in firefox related to reporting incorrect values. You may want to consider customizing the quality setting.

[mobamoba 12]

Okay. But what about Kodi? Same thing happened there.

[Luke 37254]

First let's get this resolved. Thanks.

[mobamoba 12]

It must be a Firefox thing because I just tried it in Chrome and Emby remuxed but didn't transcode.

[Luke 37254]

Thanks for the feedback. As far as Emby for Kodi goes, i would open a topic in that section of the community. Thanks.

[mobamoba 12]

Okay thanks.