A switcher using shared processors has an input matrix with a plurality of inputs to which a corresponding plurality of sources may be coupled. One or more of the sources may provide compressed data. The input matrix routes selected ones of the sources to a plurality of outputs which is less in number than the number of inputs, the routing being determined by a tally output. A pool of processors, such as compression decoders, color correctors or the like, are coupled to the outputs of the input matrix as needed for processing those sources that require such processing to provide processed data. The outputs of the processors provide processed data to a conventional switcher that combines the selected processed data to provide a program output. The conventional switcher also provides the tally output. For sources that provide inter-frame compressed data, the conventional switcher provides a preview output and a preview tally output so that the necessary time delay for decompressing such data is anticipated to minimize delay in switching the preview output to the program output. A resource management module keeps track of which processors are committed to which sources.