This it in on your HFX-9. He's demonstrating on brakes a few years newer than yours.
Yours still have a little meat on them it seems (I'd guess about 50% of new), but why don't you just spend the $30 to replace them and remove any question? The spec for the min pad thickness is 3mm (the friction material would be 1mm), if you want to measure them. New they are supposed to be 4mm total, so you're working with 1mm of material over its life. I replace them at around 0.135" on my micrometer and new they usually fall between 0.155" and 0.16". This is overall thickness, not friction material thickness.
'91 Pickup - Imelda
'08 Tacoma TRD - Donna