i can't speak chinese but here's what i think liu guoliang is saying in the first three minutes:
0:03: "okay, now try cross court."
0:10: "did you see that? that one was slower!"
0:20: "failed national player, fetch us a ball!"
0:27: "dude, your technique is all messed up. your shoulder is like this when it should be like this. see this? and now this."
0:41: "i'll pretend i didn't even see that one. try again!"
0:51: "okay, but i said cross court."
1:00: "you gotta go POW!"
1:02: liu drives the ball past xu xin and looks at him expecting to see a look of realization on xu xin's face. xu xin has no idea what liu just did so they both stare at each other uncomfortably for three seconds.
1:06: "failed project, give me another one."
1:14: "you gotta use your body and go POW! okay? POW!"
1:23: "is that so hard to do? it's not."
1:26: "B grade player, give him a ball."
1:37: "pathetic."
1:41: "you have to use your hand like this. see this?"
2:00: "crouch down, you can't stand up straight when the ball is low. i mean you can, but that's just retarded."
2:11: "okay, good."
2:15: "oh wow, my grandma hits harder than that."
2:20: "THAT ONE was good!"
2:24: "no, you still don't get it."
2:28: "yeah that was nice, beautiful!"
2:31: "yes! that's it, now try cross court."
2:38: "did that look like a good shot to you? because it wasn't!"
3:03: "can't-smash, give me another one!"
...and so on.