Jae-one Oh

3D graphics accelerator platform for mobile devices

Even in the POST-PC era, the need for 3D graphics has steadily increased. In the design of the 3D graphics accelerator for mobile devices, the physical limitation such as power, size and input device must be considered. Moreover, the 3D graphics accelerator should reside in a single chip (SoC) with other blocks such as CPU, audio, video decoder and peripheral blocks. This work describes the design and implementation of mobile 3D graphics accelerator platform. We propose a mobile 3D graphics accelerator platform that has good performance and small size, and supports standard 3D graphics API (application programming interface). Proposed 3D graphics accelerator platform supports hardware Goraud shading, texture mapping, back & front face culling, Z buffering and alpha blending. This platform was verified on a FPGA test board with standard 3D API. It is suitable for cost effective mobile 3D platform such as smart phone, PDA (personal digital assistant), and other mobile devices.

Method and apparatus for encoding envelopes of harmonic signals and method and apparatus for decoding envelopes of harmonic signals

Provided are a methods and apparatuses for encoding/decoding an audio signal to efficiently encode/decode a harmonic envelope. The method of encoding an audio signal includes performing harmonic analysis with respect to an input signal to determine harmonic parameters with respect to harmonic signals; correlating the amplitudes of the harmonic signals to signals in a time domain instead of signals in a frequency domain; applying a time-frequency transformation operation to the amplitudes in the time domain to generate time-frequency transformed values in the frequency domain; and encoding the time-frequency transformed values. When expressing a harmonic envelope, the amplitudes of the harmonic signals are regarded as signals in the time domain so as to perform a time-frequency transformation and only a part from among the transformed values is selected to be encoded. Therefore, sound quality is not affected and coding efficiency greatly improves.