Notes about this video:
说明书 instruction manual, book of directions
相机说明书 camera instruction manual
打印机说明书 printer manual
说不定 maybe, can't say for sure
说不定明天他就回来了。 Maybe he will come back tomorrow.
说白了 to speak frankly
说白了，她并不喜欢你。 Frankly speaking, she doesn't like you at all.
并不 not at all, emphatically not.
说实话 to speak the truth, frankly
说实话，她并不喜欢你。 To be honest, she doesn't like you at all.