Diddy Appeals Conviction, Says Freak-Offs Were Amateur Porno and Protected by 1st Amendment

9:22 AM PT -- Arguments have officially ended in Diddy's appeal, and the judges will now begin their decision-making process. During the hearing, Diddy's lawyers mentioned Cassie Ventura's alleged drug use, which they were not allowed to present during the federal trial.

They also mentioned a "hotel night" -- another term for the freak-offs Diddy enjoyed -- with "Jane," which wasn't connected to any threat. The lawyers shared their hope for an expedited ruling on the part of the judges ... though it's unclear how long it will take them to decide.

Sean Diddy Combs could be a free man today, after his lawyers appear before a federal appeals court and argue his freak-offs were not a violation of any law ... rather, it was kinky porn that is protected by the U.S. Constitution.

Fact is ... it's a solid argument. Diddy was convicted of the Mann Act -- which prohibits the transportation of prostitutes across state lines to engage in sex acts.

Diddy's lawyers claim the Mann Act doesn't apply ... "Freak-offs and hotel nights were highly choreographed sexual performances involving the use of costumes, role play, and staged lighting which were filmed so Combs and his girlfriends could watch this amateur pornography later. Pornography production and viewing of this sort is protected by the First Amendment and thus cannot constitutionally be prosecuted."

Prosecutors call the claims "meritless," but Diddy's prosecution is not a classic Mann Act.

Diddy's legal team is also arguing the 50-month sentence is out of line with sentencing guidelines -- they say the typical sentence is 15 months. Diddy has served 19 months so far.

The Defense says the judge considered evidence connected to the more serious charges -- racketeering and sex trafficking -- of which Diddy was acquitted. In other words, any evidence of force or coercion, so says the defense, was out of bounds for the judge to consider, and that includes the Cassie video.