We consider collusion-resistant fingerprinting codes for multimedia content. We show that the corresponding IPP-codes may trace all guilty users and at the same time have exponentially many code words. We also establish an equivalence between signature codes for the A-channel and multimedia fingerprinting codes and prove that the rate of the best t-signature codes for A-channel is at least Θ(t−2). Finally, we construct a family of t-signature codes for the A-channel with polynomial decoding complexity and rate Θ(t−3).