In OE-A speak, there are brands that make boxes (OEM brands) and brands that sell boxes (Retail brands), and sometimes, they are the same. It would have been better to speak about Manufacturer and Retailer.
The Gigablue gbtrio4k, Octagon sf8008 and UClan ustym4kpro are box models from Retail brands. They are however all identical, and all made by the same OEM brand (manufacturer).
Sometimes, OE-A defines them as such, Dags being a prime example. Dags is a manufacturer, but doesn't retail. Dags OEM hardware is sold by amongst others Qviart and Xsarius. But also Technomate, Iqonios, Optimus, Mediabox, Roxxs, Force2, etc...
So in the OE-A build tree, you have a mapping between the two, so if you for example build for the Qviart Lunix4k, you actually build the mapped dags image, with Qviart Lunix4k branding,
But on the other hand Nextv is also an OEM manufacturer that doesn't retail. It makes for example the Octagon SF4008 (which defines incorrectly octagon as OEM_BRAND), the Xtrend ET7000 and ET11000 (also retailed by brands like Galaxy Innovations). But according to OE-A, the OEM_Brand is xtrend, which hasn't made any hardware in many, many years, they went bust after the release of the ET10000, and Nextv is de holder of the "Xtrend" brand.
Then off course you have Manufacturers that also retail, like Air-Digital (uses the brand Zgemma) and VU+..
And to make it even more complex, the Zgemma H7 is identical to the Vimastec VS1500, but OE-A labels the VS1500 as made by OEM manufacturer "gfutures", whiile the Zgemma is appearently made by "air-digital".
Hence my remark that it is confusing and far from consistent.
Currently in use: VU+ Duo 4K (2xFBC S2), VU+ Solo 4K (1xFBC S2), uClan Usytm 4K Ultimate (S2+T2), Octagon SF8008 (S2+T2), Zgemma H9.2H (S2+T2)
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