Thanks for your answers.
A specific situation here is that our application must be offline first because it will be used in areas without any internet connection. So in that manner, we should probably provide videos and images with functions, so they could be executed to realm when the connection is gained.
@MaBeuLux88_xxx I think that solution for images with S3 is okay. But is there any example with videos? How are they uploaded and sent to Realm functions from client(in my case specific -Android)?
@Adam_Holt thanks for your answer but in our case, functions are must if i read documentation correctly