Film production is an important application for generative audio, where richer context is provided through multiple scenes. In ReelWave, we propose a multi-agent framework for audio generation inspired by the professional movie production process. We first capture semantic and temporal synchronized "on-screen" sound by training a prediction model that predicts three interpretable time-varying audio control signals comprising loudness, pitch, and timbre. These three parameters are subsequently specified as conditions by a cross-attention module. Then, our framework infers "off-screen" sound to complement the generation through cooperative interaction between communicative agents. Each agent takes up specific roles similar to the movie production team and is supervised by an agent called the director. Besides, we investigate when the conditional video consists of multiple scenes, a case frequently seen in videos extracted from movies of considerable length. Consequently, our framework can capture a richer context of audio generation conditioned on video clips extracted from movies.