【摘要】 优化了MPEG-2/4AAC编码器的复杂度,并在定点数字信号处理器(DSP)上实现了相应的优化编码器。提出了一种迭代求解非线性频谱量化比例因子的方法及一种不需要再量化的比特率控制方法。与定点DSP实现技术相结合,这两种方法可将编码器的运行效率相对参考代码提高30倍,而音质只有轻微下降。这使得移动设备上的高质量音频应用成为可能。更多还原

【Abstract】 The low complexity optimization of MPEG-2/4 AAC audio encoder and its implementation on a fixed- point DSP are presented. An iterative scale factor finding method for nonlinear spectral quantization and a requantization free method for bitrate control are proposed. Combined with fixed-point implementation techniques, they cut cycle usage by a factor of 30 compared to the original AAC reference codes, while audio quality only declines slightly. This enables high-quality audio applications on mobile devices.更多还原