[yologuy]

Looks like I can't edit my post I don't know why.
Sorry for the double post.

Here the python3 script, which also removes the user_id from the video

import os
import shutil

headerSize = 48

def decrypt_file(encryptedFile, decryptedFile):
	shutil.copy(encryptedFile, decryptedFile)

	with open(decryptedFile, "r+b") as inputFile:
		# Remove the user ID
		videoIdEmplacement = headerSize * 2 - 3
		inputFile.seek(-videoIdEmplacement, os.SEEK_END)
		inputFile.write(bytes([0x00, 0x00, 0x00, 0x00]))

		# Read the encrypted header
		inputFile.seek(-headerSize, os.SEEK_END)
		encryptedHeader = bytearray(inputFile.read(headerSize))

		# Xor the header
		decryptedHeader = bytes([b ^ 0x2E for b in encryptedHeader])

		# Write the original file header
		inputFile.seek(0, os.SEEK_SET)
		inputFile.write(decryptedHeader)


inputVideoFile = r"inputVideoFile"
mp4VideoFile = r"outputVideoFile.mp4"

decrypt_file(inputVideoFile, mp4VideoFile)

Enjoy guys

Note that looking at the app, the encryption seems different on android, so just in case I'm on a PC that may differ with a mac I don't know.