Dolby Laboratories

About: Dolby Laboratories is a company organization based out in Amsterdam, Netherlands. It is known for research contribution in the topics: Audio signal & Audio signal flow. The organization has 956 authors who have published 1726 publications receiving 29456 citations.

Methods and systems for generating filter coefficients and configuring filters

Abstract: Methods for generating a palette of feedback (IIR) filter coefficient sets and using the palette to configure (e.g., adaptively update) a prediction filter which includes a feedback filter, and a system for performing any of the methods. Examples of the system include an encoder, including a prediction filter and configured to encode data indicative of a waveform signal (e.g., samples of an audio signal), and a decoder. In some embodiments, the prediction filter is included in an encoder operable to generate (and assert to a decoder) encoded data including filter coefficient data indicative of the selected IIR coefficient set with which the prediction filter was configured during generation of the encoded data. In some embodiments, the timing with which adaptive updating of prediction filter configuration occurs or is allowed to occur is constrained (e.g., to optimize efficiency of prediction encoding).

Region sizing for macroblocks

Abstract: Coding techniques for a video image compression system involve improving an image quality of a sequence of two or more bi-directionally predicted intermediate frames, where each of the frames includes multiple pixels. One method involves determining a brightness value of at least one pixel of each bi-directionally predicted intermediate frame in the sequence as an equal average of brightness values of pixels in non-bidirectionally predicted frames bracketing the sequence of bi-directionally predicted intermediate frames. The brightness values of the pixels in at least one of the non-bidirectionally predicted frames is converted from a non-linear representation.

Asynchronous sample rate conversion using a digital simulation of an analog filter

Abstract: The sample rate of a digital signal is converted by a digital simulation of an analog filter. The simulation can update the states of complex poles in the analog filter at arbitrary times using different techniques. One technique updates the states at variable rates. Other techniques update the states at a fixed rate in response to values of input or output samples that are modified to account for offsets between the times of the samples and the times the states are updated. The states may be updated by using interpolations of complex exponential functions. Values of the complex exponential functions may be obtained from a product of values obtained from multiple lookup tables.

Immersive audio communication

Abstract: A method and system for using spatial audio in a virtual environment, which is capable of running on portable devices with limited processing power, and utilising low bandwidth communication connections. The system identifies a first avatar in the virtual environment; and determines if the avatar satisfies a reuse criterion, which will enable the system to reuse the audio information which has been generated for a second avatar in the virtual environment for the first avatar.

Method and system for encoding audio data with adaptive low frequency compensation

Abstract: A method for determining mantissa bit allocation of audio data values of frequency domain audio data to be encoded. The allocation method includes a step of determining masking values for the audio data values, including by performing adaptive low frequency compensation on the audio data of each frequency band of a set of low frequency bands of the audio data. The adaptive low frequency compensation includes steps of: performing tonality detection on the audio data to generate compensation control data indicative of whether each frequency band in the set of low frequency bands has prominent tonal content; and performing low frequency compensation on the audio data in each frequency band in the set of low frequency bands having prominent tonal content as indicated by the compensation control data, but not performing low frequency compensation on the audio data in any other frequency band in the set of low frequency bands.