Preventing re-encoding of videos sent in iMessage app?

Our iMessage app sends user generated videos via the new

activeConversation?.sendAttachment(movieFileURL, withAlternateFilename: nil, completionHandler:{...})


I noticed that videos sent this way always appear to get re-encoded with a bit rate of about 1Mbit/s.

Is there any way to prevent this re-encoding (and the resulting quality loss)?

I experimented with different video resolutions and encoding settings, as well as with using MSMessageTemplateLayout instead, but without success so far.


I noticed that Animoji video messages do get sent with a bitrate closer to 2Mbit/s, but maybe that is using private APIs? Or because they are 60fps instead of 30fps?