Brightsign

Brightsign Authoring
Brightsigns can be authored in two ways. 
The first way is by using their Brightsign Author(ing) tools. This application used to be Windows only and was super clunky. It may have improved dramatically by now, but historically, throwing some basic scripts into a .brs file and throwing it on an SD card was a faster path to success. 
Here's a link to a Brightsign post from 2015 with a bunch of basic autorun scripts and here's the language reference etc
Play All 1080i
Here's a script that will play all video files, in order and then loop. Open up your favorite code editor and save this file as "autorun.brs"
debug=false
VideoResolution$="1920x1080x60i"
v=CreateObject("roVideoPlayer")
p=createobject("roMessagePort")
v.SetPort(p)
v.SetVolume(50)
mode = CreateObject("roVideoMode")
mode.SetMode(VideoResolution$)
count=0
playcount=0
countFound=0
countMax=100
DIM mylist[countMax]
read:
list=ListDir("/")
for each file in list
	if ucase(right(file,3)) = "MOV" or ucase(right(file,3)) = "MP4" or ucase(right(file,3)) = "MPG" or ucase(right(file,3)) = "VOB" or ucase(right(file,2)) = "TS" then 
		mylist[countFound]=file
		countFound=countFound+1
	endif
next
play:
if countfound=0 then goto read
if debug print mylist[count]
ok=v.PlayFile(mylist[count])
playcount=playcount+1
'advancing count
if count = countFound-1 then
	count=0
else
	count = count+1
endif
if ok=0 then
	if debug then print "Playback failed"
	goto play
endif
loop:
	msg=wait(0,p)
	if debug print type(msg)
if type(msg) = "roVideoEvent" then
		if msg.GetInt() = 8 then
			goto play
		endif
	endif
	
goto loop