Change of container and audio transcoding results in bitrate drop

[JohnMason1 2]

I am trying to understand what Emby is doing here and hopefully confirm it's not reducing video quality.

My cousin is currently watching an episode, and the dashboard shows me this:

His account is set to NOT allow video transcoding, but to allow audio transcoding and container changes. So, the way I understand it is, Emby is changing the container (does Chrome not support MKV?), and also transcoding the Audio (lack of Chrome support for EAC? necessary because he only has 2 speakers and not a 5.1 system?).

But, why does it say "reducing bitrate due to quality setting"? The video is direct-playing, and EAC audio is usually less than 1Mbps, so why the reduction by 4Mbps?

 

 

Edited October 15, 2024 by JohnMason1

[visproduction 315]

I believe when transcoding is demanded due to incompatible audio, direct play is no longer possible.   Then if the video mbps from the original media is somewhat high for the connection and user's hardware, than that would be transcoded to fit the throughput and hardware that is tested on connection.  I didn't write the code and I actually never use transcoding, so this is only my guess.

Yes, EAC3 is not supported by most browsers.  I am not aware of any that do support it.  Does someone know if there is a browser with a plug-in that works?
I test by just dropping a mp4 video with different audio codecs.  The mp4 h.264 video will playback fine, so if the file just downloads, then it is the audio that is not compatible.  There is also an EAC audio codec which is older and should work on browsers.  The codec naming is rather confusing.

I believe transcoding can be triggered by EAC3 audio and most of the time for workstation browsers MKV with h.265 doesn't play direct either.  Some TV's can do it.  If someone has better info, please go ahead and list the options.

https://softhandtech.com/what-is-the-difference-between-ac3-and-eac3/

Something that did surprise me is that MKV with h.265 and many different audio codecs playback fine from a decent blu-ray player.  All you need it the .mkv file.  This is nice if you have a blu-ray player.  I did not expect that to work.

Edited October 15, 2024 by visproduction

[Happy2Play 9780]

36 minutes ago, visproduction said:

Yes, EAC3 is not supported by most browsers.

Yep

Should check each browser as most will all have different support.

HTML5test - How well does your browser support HTML5?

codec support

Media MIME Support

 

But will need to see at least the ffmpeg log.

 

[GrimReaper 4740]

42 minutes ago, visproduction said:

I am not aware of any that do support it.  Does someone know if there is a browser with a plug-in that works?

 

[JohnMason1 2]

18 hours ago, visproduction said:

Then if the video mbps from the original media is somewhat high for the connection and user's hardware, than that would be transcoded to fit the throughput and hardware that is tested on connection.

Hmm that shouldn't happen though as that user's account is set not to transcode video, and also Emby does indicate that the video is direct-playing. If it's direct playing, there should be no change in the bitrate, right?

I understand many (most?) browsers don't support EAC audio and it makes sense for the audio only to be transcoded. Plex does the same thing (and I believe Jellyfin too, but Jellyfin's transcoding/directplaying indications are a mess), and it does not reduce (nor says it reduces) the bitrate.

To be clear, I don't think the video bitrate is reduced, and I don't think the video is transcoded. The server load remains very low, nothing like when it's transcoding. I think at this stage it might be that Emby is incorrectly showing this message.

[rbjtech 5284]

1 hour ago, JohnMason1 said:

Hmm that shouldn't happen though as that user's account is set not to transcode video, and also Emby does indicate that the video is direct-playing. If it's direct playing, there should be no change in the bitrate, right?

I understand many (most?) browsers don't support EAC audio and it makes sense for the audio only to be transcoded. Plex does the same thing (and I believe Jellyfin too, but Jellyfin's transcoding/directplaying indications are a mess), and it does not reduce (nor says it reduces) the bitrate.

To be clear, I don't think the video bitrate is reduced, and I don't think the video is transcoded. The server load remains very low, nothing like when it's transcoding. I think at this stage it might be that Emby is incorrectly showing this message.

Agreed - it's the reason that is incorrect.

Technically you are 'transcoding' even if it's just the audio that is being changed - as AV is interleaved - it just means that a 'copy' process is done to video stream, as opposed to re-encode.

[Luke 42079]

Quote

reducing bitrate due to quality setting

Actually what's happening here is this label is just incorrect. It's a quirk that's happening with your combination of user restrictions. It's something that needs to be looked at.