公开(公告)号：US08346547B1

公开(公告)日：2013-01-01

申请号：US12780634

申请日：2010-05-14

Applicant: Lijie Tang

Inventor： Lijie Tang

IPC: G10L21/00 ,  G10L19/14 ,  G10L19/00

CPC classification number: G10L19/035

Abstract: 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%.

公开(公告)号：US08548816B1

公开(公告)日：2013-10-01

申请号：US12626161

申请日：2009-11-25

Applicant: Lijie Tang ,  Ke Ding

Inventor： Lijie Tang ,  Ke Ding

IPC: G10L19/02

CPC classification number: G10L19/035

Abstract: 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.

Abstract translation: 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。