Senior Constable Rowan Baldam delivered a powerful and emotional victim impact statement in Warrnambool County Court on Wednesday.

He said he was beaten to the ground, attacked and "totally incapacitated" in the fetal position after Warrnambool's Steven Cleary, 50, struck him to the head with a metal bat on October 9 last year.

"I knew at that moment that I was going to die," the police officer told the court.

Cleary pleaded guilty on Wednesday to affray, intentionally causing injury, assaulting an emergency worker on duty and two summary charges of resisting an emergency service worker.

The court heard Senior Constable Baldam and his best mate and colleague Constable Will Ringin attended a routine job at Warrnambool's McGennan Street at 3.43pm.

It was at the height of the coronavirus pandemic when masks were mandated outside, and the officers had stopped a male youth and woman who were mask-less near the Warrnambool golf course.

The court heard the youth spoke to someone on a walkie talkie shortly before Cleary arrived at the scene armed with a metal baseball bat, which was covered by a black nylon sheath.

The youth grabbed hold of one of the officer's firearms, prompting a scuffle.

Cleary then struck the officer to the head with the bat, forcing him to the ground.

As the victim lay in the fetal position in extreme pain, Cleary continued to strike him multiple times with "immense force", prosecutor Damien Hannan said.

He said Constable Ringin managed to pry the bat from Cleary as the youth punched him to the back of the head.

Mr Hannan said Cleary then took hold of a taser and fired it at Constable Ringin with a single projectile hitting his vest.

During the incident, Cleary repeatedly said he was the king, the incident was "an act of war" and he commanded the officers to get off him.

Additional police members attended and Cleary was arrested.

The entire incident was captured on police body-worn cameras.

Judge Hassan released the footage to the media on Wednesday, stating it was an important factor in the case.

Senior Constable Baldam said the incident escalated within seconds to a "life and death situation".

"And I was losing," he told the court.

Senior Constable Baldam said it was only due to the heroism of Constable Ringin that he was alive.

He said he was convinced without his friend's intervention he would have been beaten to death.

The officer said the incident left him feeling scared and alone.

He said he used to imagine a life-time career in the police force but he now found it mostly joyless.

Constable Ringin said while his injuries weren't significant, he was left in a state of immense shock.

He said the image of Cleary swinging the bat at one of his best mates, who lay defence-less on the ground, would stay with him forever.

The constable told the court he thought of the assault daily and attending work was the "greatest reminder of the worst day of my life".

"I don't know if I will ever be the same," he said. "It appears my career with Victoria Police is all but over."

Jonathan Barrera, representing Cleary, said his client suffered childhood trauma which led to delusional beliefs that were "clearly active" at the time of the offending.

He said Cleary strongly believed COVID-19 was a conspiracy, that he was "the king" and police had to adhere to his commands.

Mr Barrera said the pandemic "collided with (Cleary's) paranoia", causing his eruption of violence.

Cleary has no criminal history. He has spent more than 280 days in custody on remand.

Judge Hassan adjourned sentencing until Friday.

She ordered Cleary be assessed for a community correction order, but made it clear to the court she had not made any decisions yet about the man's ultimate sentence.

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