公开(公告)号：US08799002B1

公开(公告)日：2014-08-05

申请号：US14029240

申请日：2013-09-17

申请人： Marvell International Ltd.

发明人： Lijie Tang ,  Ke Ding ,  Zhengyuan Quan

IPC分类号： G10L19/00

CPC分类号： G10L19/035

摘要： An efficient approach for estimating scalefactors for use in the quantization of audio signal spectrum values is described. The scalefactor estimation approach can be implemented in multiple stages. A first stage estimates a distortion level for a selected scalefactor band spectrum value based on a received maximum tolerant distortion threshold and the spectrum values in the scalefactor band. A second stage determines an interim process value based on the previously estimated distortion level and generates a scalefactor for a selected scalefactor band spectrum value based on the generated interim process value and a statistically predetermined fraction. A third stage generates a scalefactor that applies to the whole scalefactor band based on the scalefactor generated for the selected scalefactor band spectrum value. The approach provides a performance gain of 40% over previous techniques, thereby reducing device power requirements and audio encoder bottlenecks.

摘要翻译： 描述了用于估计在音频信号频谱值的量化中使用的比例因子的有效方法。 比例因子估计方法可以在多个阶段实现。 第一级基于接收的最大容限失真阈值和比例因子频带中的频谱值来估计所选择的比例因子频带频谱值的失真电平。 第二阶段基于先前估计的失真水平来确定中间过程值，并且基于所生成的中间过程值和统计预定分数来生成所选择的比例因子频谱频谱值的比例因子。 第三级基于为所选择的比例因子频带频谱值生成的比例因子产生适用于整个比例因子频带的比例因子。 该方法比以前的技术提供了40％的性能提升，从而降低了设备功率需求和音频编码器瓶颈。

公开(公告)号：US08595003B1

公开(公告)日：2013-11-26

申请号：US13721625

申请日：2012-12-20

申请人： Marvell International Ltd.

发明人： Lijie Tang

IPC分类号： G10L21/00 ,  G10L19/00

CPC分类号： G10L19/035

摘要： An advanced audio coding (AAC) encoder quantization architecture is described. The architecture includes an efficient, low computation complexity approach for estimating scalefactors in which a base scalefactor estimate is adjusted by a delta scalefactor estimate that is based, in part, on global scalefactor adjustments applied to the previously quantized/encoded frame. Using such feedback, the AAC encoder quantization architecture is able to produce scalefactor estimates that are very close to the actual scalefactor applied by the subsequent quantization and encoding process. The architecture further includes a frequency hole avoidance approach that reduces a magnitude of an estimated scalefactor to avoid generating frequency holes in quantized SFBs. The efficient, low computation complexity scalefactor estimation approach combined with the frequency hole avoidance approach allows the described AAC encoder quantization architecture to achieve high audio fidelity, with reduced noise levels, while reducing processing cycles and power consumption by approximately 40%.

摘要翻译： 描述了高级音频编码（AAC）编码器量化架构。 该架构包括用于估计比例因子的有效的低计算复杂度方法，其中基本比例因子估计由基于部分地基于应用于先前量化/编码帧的全局比例因子调整的增量比例因子估计来调整。 使用这样的反馈，AAC编码器量化架构能够产生非常接近由随后的量化和编码处理应用的实际比例因子的比例因子估计。 该架构还包括减少估计的比例因子的幅度以避免在量化的SFB中产生频率孔的频率空穴回避方法。 与频率空穴回避方法相结合的高效，低计算复杂度的比例因子估计方法允许所描述的AAC编码器量化架构实现高音频保真度，降低噪声水平，同时将处理周期和功耗降低约40％。