Judge Jane McMeeken placed the teen on an "informal plan" and ordered to attend Youth Drug Court after concerns over cannabis use.
She said the charge was considered very serious, so much so that it has a maximum penalty of 10 years in jail.
Possession of the video was "incredibly disrespectful" to the victims and the "ongoing sorrow" that is being felt after the March 15 attack.
He nodded when she told him: "I hope that you understand that now."
The boy's family are distressed by what's happened and are supporting him, the court heard.
The plan he's been placed on says he has to attend school every weekday and bans him from using internet-capable devices outside of study.
The plan will be reviewed weekly and the boy will come back before Judge McMeeken for regularly progress reports. He's also on a 7pm-7am curfew.