Wakeup attacks

[Shadowfire]

Wakeup attacks' timings

Forgive me if this has been answered already but I couldn't find it if so. What exactly is the timing on wakeup attacks for each downed state? Namely:

1. After a tech roll
2. After a normal knockdown
3. After play dead
4. After a splat down or other special state

I don't know if it's just input delay online, but for some reason I can never get wakeups to come out consistently after anything but a tech roll. It seems like most of the time either nothing comes out, or I'll stand up and do an attack with no invincibility frames. Any thoughts?