A modular transcoder software system for transcoding a multimedia message includes a collection of software modules and objects for the dynamic construction of a series of complex, related or unrelated operations in the form of a transcoding pipeline. The transcoding pipeline provides a hierarchy of operations, such that they can be organized and optimized with the aim of being able to execute the entire hierarchy in a single pass. Additionally, external plugins can customize the mechanism of building the pipeline by altering, adding to, or removing construction knowledge.