From the linked comment, it appears it's not on the chip. > "In future we’ll have to do something, but for Pi 5 we feel the hardware encode is a mm^2 too far."

From the linked comment, it appears it's not on the chip. > "In future we’ll have to do something, but for Pi 5 we feel the hardware encode is a mm^2 too far." My interpretation of this is they felt the benefit did not outweigh the cons of the die space.