1
Wei Ge Chen, Naveen Thumpudi, Ming Chieh Lee: Quantization matrices based on critical band pattern information for digital audio wherein quantization bands differ from critical bands. Microsoft Corporation, Klarquist Sparkman, August 23, 2005: US06934677 (97 worldwide citation)

Quantization matrices facilitate digital audio encoding and decoding. An audio encoder generates and compresses quantization matrices; an audio decoder decompresses and applies the quantization matrices. The invention includes several techniques and tools, which can be used in combination or separat ...


2
Wei Ge Chen, Naveen Thumpudi, Ming Chieh Lee: Quality and rate control strategy for digital audio. Microsoft Corporation, Klarquist Sparkman, April 11, 2006: US07027982 (75 worldwide citation)

An audio encoder regulates quality and bitrate with a control strategy. The strategy includes several features. First, an encoder regulates quantization using quality, minimum bit count, and maximum bit count parameters. Second, an encoder regulates quantization using a noise measure that indicates ...


3
Wei Ge Chen, Naveen Thumpudi, Ming Chieh Lee: Quality improvement techniques in an audio encoder. Microsoft Corporation, Klarquist Sparkman, July 3, 2007: US07240001 (51 worldwide citation)

An audio encoder implements multi-channel coding decision, band truncation, multi-channel rematrixing, and header reduction techniques to improve quality and coding efficiency. In the multi-channel coding decision technique, the audio encoder dynamically selects between joint and independent coding ...


4
Naveen Thumpudi, Wei Ge Chen: Multi-channel audio encoding and decoding with multi-channel transform selection. Microsoft Corporation, Klarquist Sparkman, March 10, 2009: US07502743 (44 worldwide citation)

An audio encoder and decoder use architectures and techniques that improve the efficiency of multi-channel audio coding and decoding. The described strategies include various techniques and tools, which can be used in combination or independently. For example, an audio encoder performs a pre-process ...


5
Wei Ge Chen, Ming Chieh Lee, Naveen Thumpudi: Parametric compression/decompression modes for quantization matrices for digital audio. Microsoft Corporation, Klarquist Sparkman, November 28, 2006: US07143030 (41 worldwide citation)

Quantization matrices facilitate digital audio encoding and decoding. An audio encoder generates and compresses quantization matrices; an audio decoder decompresses and applies the quantization matrices. For example, the audio encoder generates a quantization matrix including weighting factors and p ...


6
Naveen Thumpudi, Wei Ge Chen: Quantization and inverse quantization for audio. Microsoft Corporation, Klarquist Sparkman, November 20, 2007: US07299190 (38 worldwide citation)

An audio encoder and decoder use architectures and techniques that improve the efficiency of quantization (e.g., weighting) and inverse quantization (e.g., inverse weighting) in audio coding and decoding. The described strategies include various techniques and tools, which can be used in combination ...


7
Wei Ge Chen, Naveen Thumpudi, Ming Chieh Lee: Adaptive window-size selection in transform coding. Microsoft Corporation, Klarquist Sparkman, December 2, 2008: US07460993 (35 worldwide citation)

A transform coder adaptively configures window sizes for transform coding in a two-pass process to maximize coding efficiency, while achieving necessary time resolution to avoid pre-echo. In a first pass, the coder places small size windows over detected transient regions of an input signal in an op ...


8
Wei Ge Chen, Naveen Thumpudi, Ming Chieh Lee: Techniques for measurement of perceptual audio quality. Microsoft Corporation, Klarquist Sparkman, December 5, 2006: US07146313 (35 worldwide citation)

An audio processing tool measures the quality of reconstructed audio data. For example, an audio encoder measures the quality of a block of reconstructed frequency coefficient data in a quantization loop. The invention includes several techniques and tools, which can be used in combination or separa ...


9
Naveen Thumpudi, Wei Ge Chen: Multi-pass variable bitrate media encoding. Microsoft Corporation, Klarquist Sparkman, March 11, 2008: US07343291 (31 worldwide citation)

An encoder uses multi-pass VBR control strategies to provide constant or relatively constant quality for VBR output while guaranteeing (within tolerance) either compressed file size or, equivalently, overall average bitrate. The control strategies include various techniques and tools, which can be u ...


10
Naveen Thumpudi, Wei Ge Chen, Chao He: Coding and decoding scale factor information. Microsoft Corporation, Klarquist Sparkman, May 26, 2009: US07539612 (26 worldwide citation)

Techniques and tools for representing, coding, and decoding scale factor information are described herein. For example, during encoding of scale factors, an encoder uses one or more of flexible scale factor resolution selection, spatial prediction of scale factors, flexible prediction of scale facto ...