| Summary: | 碩士 === 國立嘉義大學 === 資訊工程學系研究所 === 96 === In this thesis, we propose a rate control mechanism using DBA (DCT-Spectrum Bitrate Abundance) parameter to measure the frame complexity in bit-rate estimation. DBA is obtained by multiply the energy of quantized DCT spectrum by the frequency-characteristic parameter . Because the DBA parameter has high association with coding bitrate, it can offer more accurate bit-rate estimation over MAD without complex computation. Through it is involved in the quantization parameter (QP), it can be still straightforward implemented in the quantization decision mechanism recommended in H.264/AVC JVTG012 by replacing MAD by it to afford more suited QPs for MBs. Thus, channel bandwidths can be more effectively utilized under maintaining good coding visual quality. Through our offline analysis, it can be proved that the lower regression error can be obtained in versus bitrate mapping than versus bitrate mapping. The experiment results demonstrate that our method has higher PSNR than JVT-G012 using MAD, while the output bitrate it controlled close to its target bitrates.
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