For an MPEG layer audio decoder, this single chip might become a solution. This is VS1001k chip that supports MPEG 1 & 2, and 2.5 extensions, all their sample rates and bit rates, in mono and stereo. With higher than typical voltages, VS1001k may operate with CLKI upto 30..32 MHz. However, the chips are not qualified for this kind of usage. If necessary, VLSI Solution Oy can qualify chips for higher clock rates for quantity orders. In this datasheet file, there is example wiring diagram how to use this chip. For example is typical connection diagram using BGA-49. Ground buffer GBUF can be used for common voltage (1.37 V) for earphones. This will eliminate the need for large isolation capacitors on line outputs, and thus the audio output pins from VS1001k may be connected directly to the earphone connector. If GBUF is not used, GBGND and GBVDD should not be connected. In addition, LEFT and RIGHT must be provided with 100 ¹F capacitors. Full pdf file here.