Can I disable transcoding? / what causes it even when direct stream enabled?

[orbosphere 3]

Given a linux emby server, and files shared via SMB on the network, and the optional network path provided in Emby settings for the library source to provide direct play, 

Why are there still circumstances where Emby will think it needs to transcode a file? 

If I'm seeing "TranscodeReasons=AudioCodecNotSupported", or other TranscodeReasons when trying to play on iOS or AppleTV / tvOS, where is the codec not supported? By the players inside the emby iOS/tvOS player app? 

Let's say a file such as: 
 

...2020.2160p.HDR.UHD.BluRay.DTS-HD.MA.5.1.2Audio.x265-10bit-HDS.mkv

Both iOS/tvOS are able to play this same file directly in the VLC app. Why is it any different to try and "direct play" a file through the emby app? 

My server is on a Pi 4. When files transcode, they end up stuttering every couple seconds, making things unwatchable. But my platforms for viewing should be able to play my library directly- that's how I've been operating with Kodi & VLC apps for years now. 

Can anyone help diagnose in my transcode logs why transcoding is occurring, and why it causes playback to be laggy? (is the Pi4 not powerful enough?)

Is there any way I can fully disable transcoding? 

VLC is open source... I'd offer to help with iOS or tvOS development if you'd let me drop in VLC as a player into your iOS/tvOS apps, if that's the solution  


Thanks!

 

ffmpeg-transcode-076b811b-b0ad-44dc-a2ad-8e18c0c8ad6e_1.txt ffmpeg-transcode-d34806b4-5277-48be-bab9-b062cbc42929_1.txt

[Luke 42077]

Hi, for this example, if you select the ac3 audio track then it should direct play.

[Luke 42077]

Quote

offer to help with iOS or tvOS development

If you're a software developer then send me a PM and we can talk.

[orbosphere 3]

15 minutes ago, Luke said:

If you're a software developer then send me a PM and we can talk.

Sure, I am a dev and will send a PM. 

Unfortunately, the ac3 audio is still giving me issues. (on one hand.. that track is in Chinese, but that's my own issue and not Emby's) 
On first attempt, it started playback, but was still very choppy and felt the same as a transcode does to me. 
But I couldn't find a transcode ffmpeg log... 

but now after backing out, and trying to play it again, I am stuck with only black screen and it won't play at all. I've turned off emby server service, and back on again (tested playback of the file in VLC in between to ensure the SMB share is still up- playback worked fine there) 

and now attempts to play this same file, with the ac3 audio, still stuck all black for maybe a whole minute while I wrote this post up, and suddenly it plays for 3 seconds before freezing solid again. Lucky for me this time I got the transcode log- looks like it still transcodes with that AC3 track. 

For context- I'm trying to utilize Emby in a "wife-proof" setup. Navigating toggling AC3 or any other such hurdles will bee seen as janky, when VLC can just play in a single tap with buttery smooth frame rates.

ffmpeg-transcode-494c5add-5fc0-466f-b424-3bbb205669a9_1.txt

[Luke 42077]

10 hours ago, orbosphere said:

Sure, I am a dev and will send a PM. 

Unfortunately, the ac3 audio is still giving me issues. (on one hand.. that track is in Chinese, but that's my own issue and not Emby's) 
On first attempt, it started playback, but was still very choppy and felt the same as a transcode does to me. 
But I couldn't find a transcode ffmpeg log... 

but now after backing out, and trying to play it again, I am stuck with only black screen and it won't play at all. I've turned off emby server service, and back on again (tested playback of the file in VLC in between to ensure the SMB share is still up- playback worked fine there) 

and now attempts to play this same file, with the ac3 audio, still stuck all black for maybe a whole minute while I wrote this post up, and suddenly it plays for 3 seconds before freezing solid again. Lucky for me this time I got the transcode log- looks like it still transcodes with that AC3 track. 

For context- I'm trying to utilize Emby in a "wife-proof" setup. Navigating toggling AC3 or any other such hurdles will bee seen as janky, when VLC can just play in a single tap with buttery smooth frame rates.

ffmpeg-transcode-494c5add-5fc0-466f-b424-3bbb205669a9_1.txt 40 kB · 1 download

In that log you still have the DTS track selected.

[orbosphere 3]

Strange- must have been my mistake. 

I've tried again, I'm sure the AC3 audio was selected this time because it is in Chinese. And sure enough, it looks like there is no transcode log during playback. 
But playback is choppy every couple seconds. 

And here's where it gets strange to me. If I pause playback and wait 10-15 seconds before resuming it again, upon resuming it will play more like 10 seconds of playback without issue. Until it "catches up", and once again becomes choppy every 2-3 seconds. To me it just feels exactly the same as a scenario where the transcode can't keep up, or a streamed file can't buffer fast enough. (- Note that I recorded the attached video before I tested pausing playback and determining that the "buffered" amount increases, and playback without stutter lasts longer. But I promise that's what I'm seeing!)

I've then again tested playback of the same file, through the same SMB share, in the VLC tvOS app. No stutter, (although DTS/ English audio)

Based on that I don't think my network has any chokepoints here. And Emby seems to think no transcode is happening- evidenced by no transcode log. Yet I see some kind of buffering stutter in Emby but not in VLC or Kodi. Is playback in Emby different in some way that could cause this "buffer stutter"? Even when direct playback? Or is it a bug in the player? 

I'm attaching an emby log, a video of the playback attempt in both Emby and VLC, and an image showing there does not appear to be any transcode logs in my emby logs list.

Is there any scenario where a file transfer from SMB > Pi Emby Server > tvOS player could be happening, instead of a direct play from SMB > tvOS player? I could see that extra hop to the Pi server potentially causing a chokepoint in my case. 
Or, is there any scenario where a transcode could happen without a log being output? 

 
In the video I've intentionally avoided any full-screen views of the playback to avoid any issues sharing it here, I'm hoping that's ok. 

 

embyserver-10.txt

[orbosphere 3]

Different test- I just tried playback of an sd mpeg4 avi file (not trying to beat a dead horse here, just sharing further findings  )

Emby with MPV: Picture is entirely green and frame rate poor
Emby without MPV: Transcoding occurs, picture quality is poor / grainy
VLC: Playback is without issue. 

[Luke 42077]

Thanks for reporting. We'll take a look.