YNW Melly Smiling in Court During Murder Case Hearing

YNW Melly is putting on a brave face as he awaits trial in his double murder case ... flashing a huge grin and looking generally happy during a court hearing. 

Check out this footage from Melly's court proceedings Thursday in a Broward County courthouse ... he's smiling like a kid on Christmas and yukking it up with his legal team, despite being heavily shackled in his jail jumpsuit.

Not much happened in the hearing ... some procedural paperwork to officially add a couple lawyers to his defense team, but the mundane process didn't seem to bore Melly. 

At least from the outside, it seems like the rapper's upcoming trial doesn't have him fretting much, which is interesting ... considering prosecutors have already said they will seek the death penalty.