In the beginning of the video there's some guy saying "Calm down bro, calm down" but I don't know who.

The guy in yellow shorts at 0:15
>Let me run away please, let me run away please

The woman that got shot says in 0:25
>Who are you gonna shoot João? Who are you gonna shoot?
>Who are you going to shoot?
The man points the gun at her face and says
>In your face
She taunts him while he is attempting to clear a jam retardedly
>My face is here, shoot it then
>My face is here and your gun is here, shoot it then
>Do it João

At 0:51 someone, apparently the armed guy says "foi", which in this context is a slang that could be understood as "ready".

Just before she gets shot, the woman says
>You know when ...(unintelligible)... you are going to die, huh?

Armed man says as he enters the bar
>Get out of there (unintelligible) (possibly the name of the woman's husband, since he's the one who got shot and died inside the bar)

Everything else is unintelligible or gibberish.

A few notes:
João may or may not be the shooter's actual name. The woman calls him João in a mocking tone and it's not unusual for low class people to call people they don't know João in a context of hostility. Imagine you are at a party and some random drunk guy you've never seen before is trying to start some shit with you and keeps saying "What you gonna do John?" It's meant to be hostile as in "I don't care who you are". What gives it away is the tone of mockery.
The 2 guys who bolted in the beginning including yellow shorts guy probably know the shooter personally, they knew he was not bluffing. The people who left when the woman got shot were probably shocked with fear when they saw the gun and stood there because they didn't know what to do and were afraid of making themselves targets by trying to run so they just stood paralyzed until the man fired and the fight or flight instinct kicked in hard.
The woman that got shot was very confident that he wasn't going to shoot her, likely drunk.