1. A decoding device comprising: a storage section which stores control information, the control information showing a progress state of process stages for a decoding process as to a plurality of processing data included in coded data; a control section which allocates process stages corresponding to executable processing data which is executable in parallel, to at least one processor on the basis of the control information, a dependence relation between the processing data in the decoding process, and a dependence relation between the process stages; and a decoding processing section which parallelly executes allocated process stages corresponding to the executable processing data, wherein: the decoding processing section comprises a syntax analysis, an entropy decoding process, an inverted quantization process, an inverted DCT process, a motion vector prediction process, a filter boundary intensity determination process, a motion compensated/weighed prediction process, an in-screen prediction process, a deblocking-filter process, and an output determination process; the syntax analysis is included in a first stage; the entropy decoding process is included in a second stage; the inverted quantization process is included in the second stage or a third stage; the inverted DCT process is included in the second stage or the third stage; the motion vector prediction process is included in the third stage; the filter boundary intensity determination process is included in the third stage or a fifth stage; the motion compensated/weighed prediction process and the in-screen prediction process are included in a fourth stage; the deblocking-filter process is included in the fifth stage; the output determination process is included in a sixth stage; the first stage executes processes in series; the second stage can parallelly execute in a unit of slice, the second stage being synchronized with the first stage in a unit of slice and the third stage in a unit of macroblock; the third stage is synchronized with the fourth stage in a unit of macroblock; the fourth stage is synchronized with the fifth stage in a unit of macroblock; and the fifth stage is synchronized with the sixth stage in a unit of slice.