Live USB streaming/downloads. Ezcast Miracast+ ScreenCast.

To stream something in the manner your suggesting means that the box would have to have a streaming daemon of some type installed and running to handle the streaming of the media source on the usb/memory stick. I am not sure thats something available with LibreELEC as normally LibreELEC is handling Kodi which is really more like the client end. Some IPTV plugins i think may be able to somewhat do so because the plugin has the server end as well as the client end code in it. Theres plugins around that do have the ability but there not something i really ever mess with so i can't comment on that stuff.

As far as recording a incoming stream and being able to save it, theres a few ways of handling that which can be by coding the plugin to retain the read ahead caches and rather then pitching the data save it by writing the data to a file. Another way could involve writing code that peels the transport stream packet wrapper off and as it does so fudge the control parameters to tell the receiving device to treat the file as a download so save it without trying to view it.

hm... not really anything i have ever messed with but my quess would be that to support something like Miracast it would be something that the underlying operating system kodi is running on wound need to support it, which is why Android probably works. Kodi basically is just another application that runs ontop of something else as a OS that would provide the hardware implimentation layer so in the case of something like LibreELEC or any of its forks my quess would be that the basic support would have to start there and then allow a running app such as Kodi to make calls to that layer thru a plugin coded up to handle that.

I may be off base on what i have said but that would be my initial thoughts on the idea and if someone that knows more about the idea please feel free to correct me on the idea as i really have never messed with any of that. I just no basically Kodi inherits its hardware calls from the underlying OS which in this case would be what LibreELEC provides.

I think you're intermixing the concepts of media data stream and mirroring or screen casting when they are really 2 different things.

Streaming a media file requires a application or server daemon to handle streaming the file according to one of the accepted streaming protocols which means on top of some stream control code its also actually sending the audio/video data stream and theres no reason someone could not create or embed a daemon on LibreELEC to do that.

Things like ezcast are mirroring the display data from one device to another display device or many devices. In other words its got a dongle on one end and another dongle at the other end that plugs into the hdmi input so that when you run the dongles application on the sending device it controls the hardware dongles that talk wirelessly to send the screen data from the sending device to the receiving device dongles. The wireless mirroring signal is not from what i understand the same as a media stream that is audio/video and my quess is that its probably proprietary to dongle manufacturer.

TV's that play back media from a usb device plugged into it do so because the TV's firmware has some type of built in media player.

Don't get me wrong as i am not saying you can't do something i am just not sure how to help as i think your mixing the concepts and its making it hard to give you the answer you expect.

If you want to stream media then you need to setup something as a server to serve that data up to the network, and have it on some device such as a capable router or a NAS box.

Someone please correct me if i am wrong but from what i understand about the Ezstream product thats how it works.

Anyways.. read what you posted in that information as it proves my point, as your still missing the idea of what data is being sent from one device to the other.

One last attempt... for example: with any of those methods your referring to that doc explains it ...

say im screen sharing on my phone and want to share that display on my tv so i open up a pdf on my phone and am reading it and cursoring thru the page, you will see the identical screen now shared on the casted to or mirrored to display. or say i am using a file browser to hunt for a file on my phone i will now see that as well on the shared display.. the data being sent to the mirrored or casted to display is not the same as a audio/video stream... ya i quess you could start a movie on the phone in full screen and you would see it on the other display but now while thats running move your cursor around the screen and you'll see it do the same thing on the screen... Now i am sure that if one were to look at the actual movie files data on the phone your not going to find that information of the cursor in the data contained in the movie's data, not even in the wrappers that handle the packets that create the stream.

how anyone defines the word "Steaming" is really meaningless without understanding the data thats contained in the packetized data that creates a stream. and thats my point... as unless i misread your original inquiry about wanting to stream audio/video from your local network to your other devices which implies your wanting to stream a typical audio/video file... If you really want to understand more about streaming you should spend some time reading the DVB spec's as it covers most of the protocols and specs involved in transmitting media wether its from a sat's downstream or from internet feeds and cable's the information needs to be packetized and control via the accepted standards and understanding that may help your realize that just because something is sending wired or wireless information of any type to another device there has to be a spec or protocol to how that data is organized but not all things are the same.

to most peoples mindset Streaming implies a audio/video stream even tho something like your cell phone operates on sending and recieving data people really dont say they are streaming their phone calls.

As i said i think your misunderstanding the term streaming and the technologies involved in how those devices you keep referring to work.

also i meant to add that if you follow the specs regarding media files and how they get packetized you will come to see that retention of a audio/video file on the local device may be as simple as the commands used by the particular application or script retrieving the remote file. a file open type call will treat the file differently the a file streaming open call. those aren't the real calls, just meant to show that the commands used to get the file and help decide the method of handling the file