The terrified 17-year-old cried for help during the 10-minute recording which showed him being repeatedly assaulted while he was prevented from leaving a flat.
At one point his attacker, who cannot be named for legal reasons, could be seen posing for the camera and holding up his blood-stained hands so they could be filmed.
At Bradford Crown Court yesterday the now 17-year-old was sentenced to three-and-a-half years detention in a young offenders’ institution after he pleaded guilty to false imprisonment and assaulting the teenager, who also cannot be identified.
The court heard that he was only 16 at the time of the attack and he could not remember any of it because he had been drinking heavily and taking drugs.
The attack began in a bedroom where the youth was grabbed round the neck, punched and kicked.
When the violence continued in a bathroom the youngster could be seen cowering on the floor.
Co-accused Jamie Knapton, who filmed the violence last September, was also locked up for two-and-a-half years.
Knapton, 18, of Manchester Road, Milnsbridge, had also admitted assault and false imprisonment.
The court heard he kicked out at the complainant’s abdomen and could also be heard laughing on the mobile phone recording.
The early hours attack only came to an end when a neighbour alerted the police and they arrived on the scene.
As a result of the violence the injured teenager suffered a swollen left eye, cuts to his mouth and other bruising and swelling to his head and body.
Recorder Anthony Hawks said the pair had been high on a cocktail of drink and drugs when they carried out an unprovoked, sustained and sadistic attack on a vulnerable young man who thought they were his friends.
Although the now 17-year-old was described as the prime mover in the incident, Hawks told Knapton that he had played his part by making sure everything was filmed.
The judge said it was a chilling feature of the case that Knapton had been at pains to record the blood that the victim had shed on the bathroom floor.
“Everybody who has been present in this court in the last 20 minutes will have been sickened by the spectacle which you Knapton chose to record in the early hours of that day, the 9th of September last year,” the judge told the two defendants.
He branded the duo’s behaviour as “disgusting and inhumane” and added: “One dreads to wonder what would have happened had a neighbour not alerted the police as to what was going on. There was no sign of it coming to an end from either of you.”
The 17-year-old’s barrister Gillian Batts said he had been living independently for the first time and had spiralled out of control at the time he committed the offences. She said he had started using illicit substances following a personal tragedy and he attributed his behaviour and his inability to remember the incident to those substances.
Barrister Jason Pitter, for Knapton, said he had expressed genuine remorse and was disgusted by his behaviour.