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Apple TV 4K - Always transcoding


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Hello emby team,


Thank you so much for an awesome product. I left Plex a few years ago and have never looked back again.


My main clients until rather recently have been x2 Minix Android devices running Emby for Android TV. These have been playing all of my content (besides H264 High 10) without any need for transcoding of the video stream. However since I swapped them out for Apple TV units it seems that all of my media requires transcoding.


My initial concern regarding this was my h265 content but unless I am reading the logs incorrectly it would seem that even h264 content is being run through ffmpeg. In the H264 sample I've attached, the subtitle is not supported by the apple TV unit but it would seem that in addition to this the server is recoding the video stream as well?

Stream mapping:  Stream #0:0 -> #0:0 (h264 (native) -> h264 (libx264))  Stream #0:1 -> #0:1 (copy)

Also for your information. Regarding the h265 content, I have run some tests with ffmpeg rewriting the tag with "-tag:v hvc1". This has allowed me to stream the files through iTunes (In mp4 format).


Server & Client versions


Server: Debian 3.16.51-3+deb8u1

Client: Apple TV 4K - tvOS 11.2.5


Thank you for any assistance you can provide!





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Hi.  The Apple TV has very limited format support while the Android TV has very wide format support.


So, that is why you are seeing an increase in transcoding.  In order to "burn in" subs, the video must be processed.


Are you experiencing any actual playback issues?

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Hi ebr. Thank you for your prompt response.


I am very well aware of the limitations in apple products. It's the main reason I started looking into transcoding servers a few years back as my at the time new iPad 3 refused to handle MKV containers.


Currently the only actual playback issue i am experiencing is the occasional missing subtitles but I was planning on writing a separate post for that. The intention of this topic was to investigate what needs to be done to get the Apple TV to work as well as possible with my archive without massive restructuring of the data.


The main reason why I waited for the 4K was because of its support for HEVC. The unit works fine with HEVC media encoded with the latest Nightly Handbreak in a Mp4 container. However if put in a MKV container the media is transcoded to H264.


Is it possible for Emby to remux the MKV container to MP4 without reencoding the video stream?

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Emby should be remuxing an h264 stream in an MKV container instead of transcoding. If it’s transcoding it’s for a different reason like an unsupported audio format or subtitles.

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  • Solution

Stream mapping:

  Stream #0:0 -> #0:0 (h264 (native) -> h264 (libx264))  Stream #0:1 -> #0:1 (copy)


@@Qlan, this one transcoded due to burning in ASS subtitles. Apple TV does not support this subtitle format, therefore we have to burn it in with transcoding.


To avoid this, either turn the subtitles off, or consider acquiring external srt subtitles.

Does this answer your question on that?

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As always thank you for all your detailed answers and yes I feel like the question has been answered :)


I have allot of anime content in my archive which has subtitles of many different formats so I'll just have to deal with the transcoding for these.


Would it perhaps be possible as a future feature for the Emby server to be able to extract and "flatten" custom subtitles to make them compatible with the target device?

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