I am trying to download to local folder on a pixel 7. App is up to date, used to work but I see the file in the queue but it shows HTTP 500 error. Attaching log.
Template is not really filled …
Anyway I can’t tell much more that what the error says, your Emby server returns error 500 you need to check in their logs why they fail to transcode the media.
Edit##
I had a max bitrate for cached and downloaded songs set in this app. Turned that is and all is well. Thanks for the help.
Emby logs would still be nice to know why it fails it should work 
“-c:a:0 libopus -ab:a:0 262144”
“06:30:18.795 [libopus @ 000001964ce735c0] The bit rate 262144 bps is unsupported. Please choose a value between 500 and 256000.”
This is showing up in the log. (I had selected 256)
ffmpeg-transcode-e5cc5556-7bd7-4713-b265-a3ba7dd98dcc_1.txt (5.4 KB)
Wow not nice 
The values were normalized by Emby before based on the Codec they select
I guess I’ll have to do it on my side now.
Here is what Luke (a dev) said on the Emby forum.
The app is requesting a conversion to opus, which I understand why you’d want to do that, but given that Emby apps don’t currently do that, we have not been putting any testing time into this. So it’s something we’ll have to look into. Immediate workaround would be to configure the app request mp3 instead.
I have seen your app transcode to opus, does that mean it was doing it client side (on the phone).
Transcoding is done by Emby by request of the app. The sent values are absolutely normal and 256 Kb is 262144 bps, most things works in Kibi in computer world
Opus is a way better codec than MP3 so that’s what is used since Symfonium support it.
Emby should not transcode either if the request bitrate is higher than the current media bitrate as the profile says it support the media.
So if Emby transcode mp3 with lower birate to Opus there’s something wrong there.
For the bitrate that FFMpeg seems to limit to 256000 for Opus, Emby should properly handle it as it does for most case, but seems they do not handle opus so I’ll have to do it on my side for now.
Ok so Emby issue is not about the codec but the container, easier fix.