Hello Andrew,
To your questions:
"( Hikvision magic word 'SWKH')" - These letters exist at the beginning of each 'hardware descriptor block' to identify it, and can be conveniently used to find each one as there are several.
"00000010 01 ( is this line always for region) 01 is eng 02 is china )" - Yes, that's the understanding of the community here, and it does seem to be correct.
"and how did you find second number ??" - I didn't find it, I chose it. It's just one of the bytes that sets the 'MAC address', and it does no great harm to change it to compensate for the change in the language byte (to keep the Checksum-16 checksum unchanged as the byte range over which it is calculated has been changed in new-manufacture cameras), and the camera firmware does not object to the changed MAC address.
"what about mtd 5 ???" - The 'hardware descriptor blocks' should all be the same on both mtdblock5 and mtdblock6.
"what about day on OSD and language mismatch for NVR which line is for this and how find second number" - It is the language byte change that fixed these. The second number is just to make sure that when subtracting 01 from the language, we add 01 somewhere else to compensate. It could have been another byte in the MAC address, this would have had the same effect.
The Aliexpress sellers are buying Chinese region cameras at low prices, and re-selling outside China. As you have seen, this can cause a 'language mismatch' if the camera is connected to an NVR that is English. So the sellers mostly help the buyers by installing modified firmware that dynamically changes the camera to English / Multi-language, and all is well. But - when the buyer upgrades the camera with original Hikvision firmware, the camera changes back to Chinese, which is how it was manufactured.
What you have done is made a permanent change to the camera hardware descriptor which converts it to English.
I hope that all makes sense!
By the way - I liked the 'IP Camera selfie' and the smile of success!
