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[Author] Chawalit HONSAWEK(3hit)

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  • Dedicated Design of Motion Estimator with Bits Truncation Fast Algorithm

    Li JIANG  Dongju LI  Shintaro HABA  Chawalit HONSAWEK  Hiroaki KUNIEDA  

     
    PAPER

      Vol:
    E81-A No:8
      Page(s):
    1667-1675

    In this paper, a dedicated hardware design for motion estimation LSI of MPEG2 is presented. Combining our bits truncation adaptive pyramid (BTAP) algorithm with Window-MSPA architecture, the hardware cost is tremendously reduced without PSNR performance degradation for mean pyramid algorithm. The core of the test chip working at 83 MHz, performs a search range of 67 for image size of 1920 1152 and achieves video rate of 60 field/s. It can be used for HDTV purpose. The chip size is 4. 8 mm 4. 8 mm with 0. 5u 2-level metal CMOS technology. The result in this paper shows our promising future to realize one chip HDTV MPEG2 encoder.

  • New Rate Control Method with Minimum Skipped Frames for Very Low Delay in H.263+ Codec

    Trio ADIONO  Tsuyoshi ISSHIKI  Chawalit HONSAWEK  Kazuhito ITO  Dongju LI  Hiroaki KUNIEDA  

     
    PAPER-Image

      Vol:
    E85-A No:6
      Page(s):
    1396-1407

    A new H.263+ rate control method that has very low encoder-decoder delay, small buffer and low computational complexity for hardware realization is proposed in this paper. This method focuses on producing low encoder-decoder delay in order to solve the lip synchronization problem. Low encoder-decoder delay is achieved by improving target bit rate achievement and reducing processing delay. The target bit rate achievement is improved by allocating an optimum frame encoding bits, and employing a new adaptive threshold of zero vector motion estimation. The processing delay is reduced by simplifying quantization parameter computation, applying a new non-zero coefficient distortion measure and utilizing previous frame information in current frame encoding. The simulation results indicate very large number skipped frames reduction in comparison with the test model TMN8. There were 80 skipped frames less than that of TMN8 within a 380 frame sequence during encoding of a very high movement video sequence. The 27 kbps target bit rate is achieved with insignificant difference for various types of video sequences. The simulation results also show that our method successfully allocates encoding bits, maintains small data at the encoder buffer and avoids buffer from overflow and underflow.

  • System-MSPA Design of H.263+ Video Encoder/Decoder LSI for Videotelephony Applications

    Chawalit HONSAWEK  Kazuhito ITO  Tomohiko OHTSUKA  Trio ADIONO  Dongju LI  Tsuyoshi ISSHIKI  Hiroaki KUNIEDA  

     
    PAPER-VLSI Design

      Vol:
    E84-A No:11
      Page(s):
    2614-2622

    In this paper, a LSI design for video encoder and decoder for H.263+ video compression is presented. LSI operates under clock frequency of 27 MHz to compress QCIF (176144 pixels) at the frame rate of 30 frame per second. The core size is 4.6 4.6 mm2 in a 0.35 µm process. The architecture is based on bus connected heterogeneous dedicated modules, named as System-MSPA architecture. It employs the fast and small-chip-area dedicated modules in lower level and controls them by employing the slow and flexible programmable device and an external DRAM. Design results in success to achieve real time encoder in quite compact size without losing flexibility and expand ability. Real time emulation and easy test capability with external PC is also implemented.