A Tasmanian man accused of violence against his ex-wife and four police officers has left the courtroom during his trial because he says the evidence to be shown was "too distressing".

Daniel Victor Gandini, who refers to himself as "Diplomat Dan" and is called "Dan" in court, is accused of three counts of assault against his former partner and of splashing acid on four police officers.

He has been representing himself in the trial in the Supreme Court in Burnie, in the state's north-west, in recent weeks.

The jury has heard the woman fled their home with their two children on the morning of July 8, 2021, and called police, triggering a large response and an 11-hour siege of the Port Sorell property, as they attempted to take Dan into custody.

On Wednesday morning, Crown prosecutor Peter Sherriff told the jury he would be playing some video footage to the jury, at which point the accused stood up and began to leave the courtroom.

"You're not allowed to leave," Chief Justice Alan Blow responded.

Dan sounded agitated as he repeated that he did not want to watch the footage.

Chief Justice Blow said that was his choice and then gave him permission to leave the courtroom but ordered that he must stay in the court building.

After his exit, the jury was shown a lengthy video that appeared to be recorded on security cameras at the front of the accused's home in the time before police arrived in the scene.

The alleged victim and the couple's young son could be seen walking back and forth between the carport and their front yard before the accused enters the frame and can be seen locking a gate and moving around in the front yard.

'He's talked about blowing up the shed': Court hears triple-0 call 

The jury was also played the call the alleged victim made to triple-0 on that morning, in which she could be heard crying and apologising to the operator.

"My husband has barricaded himself in the house … he's having a mental breakdown," the woman said.

"He's got knives, he's talked about blowing up the shed. I don't know what the hell he's doing.

"He's got mental health problems. He needs an ambulance please."

Police told they would be on CCTV

The accused remained in the courtroom while the tripl-0 audio was played and appeared to be crying and wiping tears from his eyes as he listened.

The operator told the woman she did not need to apologise and reassured her that she and the children were doing the right things.

"As long as you and the kids are safe, that's our main priority," the operator said.

She said the accused would be watching them on the security cameras, and urged the operator to tell police officers to not pull into the driveway of the house where he would be able to see them.

Mr Sherriff told the court the prosecution case was nearing its end, and the jury would soon be told whether the accused would be presenting a defence case.

The trial before Chief Justice Blow is currently in its third week.