Bachchan, 72, and 77-year-old Shashi have worked in several landmark films including "Deewar", "Do Aur Do Paanch", "Roti Kapda Aur Makaan", "Kabhi Kabhie", "Silsila", "Kaala Patthar" and "Trishul".
"Shashi ji and I have shared so much it is difficult to imagine how we did it, now, when I look back on it, asked by his son and grandson to fill in a few moments on video for the honour event in the Capital.
The "Piku" star had earlier said Kapoor is the "most deserving" of the Dadasaheb Phalke Award.
Shashi is the third from his family to get the award after father Prithvi Raj Kapoor and elder brother Raj Kapoor.
The award will be presented to him next month in the Capital.