MKV works when served from server 3.4.1 but not 3.5.3 or 3.6.0.73

[cloudwindhk 0]

Hello. I found that I have a mkv file that plays properly on the Apple TV app when served from Emby Server 3.4.1.0 but fails with the "error loading content" error starting from 3.5.0.0 all the way to the latest beta 3.6.0.73 (I tested 3.5.0.0, 3.5.3.0, 3.6.0.73). Attached are the ffmpeg logs generated in 3.4.1.0 and 3.6.0.73. I cleaned the logs directory before each attempt to play the file; the logs start from server start and end after either the playback error or after successful playback. The file plays fine in the browser regardless of Emby Server version.

3.4-ffmpeg-transcode-e0803ae1-ef54-4cf4-a659-f82c8313453f.txt

3.6-ffmpeg-transcode-1662f4ab-3a86-4be3-aa2a-3da75e2524d2_1.txt

Edited December 1, 2018 by cloudwindhk

[Luke 42077]

@@softworkz

[softworkz 5066]

@@cloudwindhk

 

The most apparent difference is the audio encoding. Can you try to modify chromecast settings to use a more basic audio output (e.g. stereo instead aac 5 chan)?

[cloudwindhk 0]

Pardon my ignorance but since this is the same file served by 3.4, 3.5, and 3.6, is the implication that 3.4 downmixed the audio to stereo whereas 3.5 onwards left it alone?

 

Also I found this issue with the Emby Apple TV app, is there an equivalent setting to try there? I unfortunately do not own a Chromecast. The Apple TV is hooked up to a 5.1 setup.

[softworkz 5066]

Sorry, I mixed that up. I was reading something about chromecast at the same time.

 

But the same goes for your Apple TV. Could you try to unplug the 5.1 and switch to a stereo setup (e.g. using analog output with a headphone)?

Not as a resolution of course - just a test.

[softworkz 5066]

BTW - emby 3.4 doesnt downmix to stereo, it converts to 5.0 channel AC3.

[cloudwindhk 0]

Got it. I found an option in the Apple TV where it controls the output audio format and changed it to stereo, and retried playback from 3.6.0.73. It worked. It does appear that the audio encoding is the issue.

 

Btw just to close out the rest of the variables, the Apple TV Emby app is 1.2.14 and the tvOS 12.1 (16J602).

Edited December 1, 2018 by cloudwindhk

[softworkz 5066]

OK, that's good, thanks for testing. Next step would be to find out whether our transcoding process is failing  or if the client is rejecting playback and caused transcoding to stop.

I would need to have a look at the main Emby log which you had originally posted but then deleted before I tried to download. You can also send it to me via PM if you prefer.

[cloudwindhk 0]

I noticed that the ffmpeg logs were being downloaded but the server logs weren't so I removed them for streamlining. I still have those files and will DM now, thanks for looking into this.

[Luke 42077]

Ok i see why it's picking aac as the audio format. i can fix that for the next beta and we'll see where we stand after that. thanks.

[cloudwindhk 0]

This has been fixed since 3.6.0.75. Thank you both.

[Luke 42077]

Thanks for the feedback.