What happens in court is irrelevant. The police will have arrested you, and they had a "reasonable pretext", so they won't face any repercussions. You, however,

What happens in court is irrelevant. The police will have arrested you, and they had a "reasonable pretext", so they won't face any repercussions. You, however, will not only lose the opportunity of filming them, but will at least spend one night in jail. You might get some damages from the city, but most likely not enough to cover the court costs of even pursuing this.