In this paper, a power-aware SNR progressive DCT/IDCT IP core design for multimedia transform coding is proposed. The proposed IP core possesses the feature of power-aware design flexibility allowing the trade-off of lower power consumption with less demand of data precision in developing its instruction library. Relationships of energy reduction and data quality degradation in the example of both JPEG still images and MPEG4 video sequences have been analyzed. Since the proposed IP core is developed based on the concept of programmable processors, we can select DCT/IDCT firmware library of different precisions of cosine coefficients according to the accuracy requirement of various applications. This design has been realized based on a 0.35-μm CMOS technology and costs about 2175 gates with S words of RAM, which can achieve the real-time processing of the texture coding in MPEG4 SP@L3 codec system for the CIF video at 30 frames per second (fps).