Emby Crash During Playback

[sfcredfox 1]

Community,

 

I'm experiencing a playback issue while trans-coding and looking for a way to address it.

 

Emby Version 4.4.2.0

Running on Windows Server 2012 R2 VM

8 CPU cores (Intel® Xeon® CPU L5640 @ 2.27GHz)

4GB RAM

Shared storage system with good performing disk

 

 

The error message is:

System.IO.IOException: System.IO.IOException: The process cannot access the file '\\172.20.16.205\Media\transcoding-temp\6F23CF_14.ts' because it is being used by another process.

 

This happens while watching a video that is 4K compressed using HEVC, and playback is the Chrome browser.  Playback of the same video is fine with a chromecast ultra.

 

As the chromecast ultra can natively support HEVC, it works fine in this case, and direct streams as needed.  I understand chrome can't natively play HEVC or the DTS/Dolby audio codecs, so transcoding will be required.  It does begin transcoding.  I can see the temporary transcoded files showing up in the temp directory.

 

My guess is ffmpeg is very slow using software to transcode HEVC, so the player keeps catching up with the transcoder and tries opening a video file while it's still being written to by ffmpeg.  I can't seem to find any buffer options to tell the player to wait until X amount before playing either.  Other video formats transcode just fine, and we can watch lesser resolution videos in chrome with no problems.  It seems the system can handle those very well, just not HEVC.

 

 

Things I've tried to fix this so far:

 

1) Adjusting the transcoding preset settings to faster options, and bumped the CRF from 23 to 25.  Since all other transcoding works fine, I'd like to not have all the other videos look like crap just to make HEVC work if possible.

 

2) Moving the transcoding temporary path to the local server drive, or other NAS locations, doesn't seem to matter.

 

3) Check CPU usage, which gets pretty close to 100% while transcoding HEVC (which is fine, it's a dedicated VM for Emby).  This VM has a very high CPU share and has more access to CPUs than any other VM, to assist with demand when transcoding.

 

4) Adjusted the transcoding thread count, doesn't seem to make any differences (it's currently on 16, which I believe is appropriate for an 8 core system)

 

5) Turned hardware acceleration off, there is no GPU hardware available to this VM, as the host system doesn't have one.

 

6) Added exceptions in anti-virus software for the transcoded videos, so they are not scanned by on-access scanners.

 

Is there any way to control buffering and tell Emby to not start playback until a certain buffer level is reached?

 

Is there any way to control transcoding quality settings of different sources?  If other video formats can be transcoded fast enough to be set at higher qualities, I'd like to keep them there.  Perhaps it just takes so much longer to transcode HEVC, that format alone needs to be set way lower if we can't force a larger buffer before playback starts?

 

 

 

I have attached server log and ffmpeg log

 

 

Thanks all

embyserverLog.txt

ffmpeg-transcode.txt

Edited May 16, 2020 by sfcredfox

[sfcredfox 1]

I wonder if this should be a bug report?

[Luke 42086]

Hi there, can you try setting the transcoding temporary path option back to the default (blank) and see if this helps? Thanks.

[sfcredfox 1]

This is how the application was originally configured (naturally), but I had to change it because the volume the application is stored on was not big enough to store the transcoded video streaming files.  I had to temporarily add an additional drive to the machine.

 

I did notice that the occurrences of the crashes has gone down since moving it (transcode temp) to a local drive instead of NAS, but it still happens.  It seems to be the biggest issue when the machine is transcoding HEVC REMUX instead of compressed down further (REMUX 75GB file vs 30-40GB @ ~30mpbs), so I imagine the FFMPEG is just not staying ahead of playback?

 

Additional note:  I upgraded to 4.4.3.0, so we'll also see if that makes any difference, but if there was no code change around transcoding/file management, probably won't.

 

Joining the ranks that have expressed love for this software

Edited June 8, 2020 by sfcredfox

[Luke 42086]

Hi, thanks for the feedback. I'm not sure the 4.4.3 update will make a difference, but please let me know once you've put it through it's paces. Thanks.