Pyrotechnics turns a fire into a burst of blinding fireworks or a thick cloud of choking smoke, depending on your choice. The spell uses one fire source, which is immediately extinguished. A fire so large that it exceeds a 20-foot cube is only partly extinguished. Magical fires are not extinguished, although a fire-based creature used as a source takes 1 point of damage per caster level.
What constitutes a fire-based creature for this purpose? I figure a fire elemental would be okay, but.. does this extend to anyone with the [fire] subtype?
"fire source" is not defined, and a creature that is fire-based so as to qualify as a "fire source" isn't either.
I wouldn't expect 'fire type' to be enough to define it as 'fire based,' in part because this language has been part of the spell in previous editions. Basically I would rule that if their are flames continuously coming off of a creature (or the creature was made of flames) it would work, but it wouldn't if not, even if it was a fire type.
So Azer, Fire Elemental and Pheonix would all be good, but Brass or Gold dragons wouldn't.
In short, GM call.