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.

Low computational-complexity digital filter bank for encoder, decoder, and encoder/decoder

Abstract: The invention relates in general to digital encoding and decoding of information. More particularly, the invention relates to efficient implementation of digital analysis and synthesis filter banks used in encoding and decoding. The invention permits the length of a digital transform used to implement critically-sampled analysis and synthesis filter banks to be adaptively selected.

Audio coding system using characteristics of a decoded signal to adapt synthesized spectral components

Abstract: A receiver in an audio coding system receives a signal conveying frequency subband signals representing an audio signal. The subband signals are examined to assess one or more characteristics of the audio signal. Spectral components are synthesized having the assessed characteristics. The synthesized spectral components are integrated with the subband signals and passed through a synthesis filterbank to generate an output signal. In one implementation, the assessed characteristic is temporal shape and noise-like spectral components are synthesized having the temporal shape of the audio signal.

Media fingerprints that reliably correspond to media content

Abstract: Quantized energy values are accessed to initially represent a temporally related group of content elements in a media sequence. The values are accessed over a matrix of regions into which the initial representation is partitioned. The initial representation may be downsampled and/or cropped from the content. A basis vector set is estimated in a dimensional space from the values. The initial representation is transformed into a subsequent representation, which is in another dimensional space. The subsequent representation projects the initial representation, based on the basis vectors. The subsequent representation reliably corresponds to the media content portion over a change in a geometric orientation thereof. Repeated for other media content portions of the group, subsequent representations of the first and other portions are averaged or transformed over time. The averaged/transformed values reliably correspond to the content portion over speed changes. The initial representation may include spatial or transform related information.

Adaptive-filter single-bit digital encoder and decoder and adaptation control circuit responsive to bit-stream loading

Abstract: An adaptive single-bit encoder and decoder has its adaptive function determined by dynamically dividing the message frequency band into delta-sigma and delta modulation regimes of operation. In a practical embodiment this is accomplished by varying the corner frequency of a variable-frequency low-pass filter (14, 14′) in a leaky integrator so that below the corner frequency the operation is that of delta-sigma modulation and above the corner frequency the operation is that of delta modulation. An adaptation control circuit (18, 18′) removes the clock signal component from the encoded bit stream to provide an analog signal representative of bit stream information or loading for use in generating the control signal. The analog signal is peak rectified (22, 22′), smoothed (24, 24′), and (optionally) non-linearly processed (26, 26′) to provide the control signal.

Audio system which not only enables the application of the surround system standard to special playback uses but also easily maintains compatibility with a surround system

Abstract: When an audio stream signal is transmitted, the bit stream information for determining the surround mode and special-use mode, including karaoke use, is sensed from the signal at a mode sensor. After the surround mode has been sensed, the audio data is converted by a decoder into a front left, front center, and front right main audio signals and a back left and back right surround audio signals in the surround mode, which are converted into analog signals and outputted to the corresponding speakers. When the special-use mode has been sensed, by using the central main audio signal of the front left, front center, and front right main audio signals and back left and back right surround audio signals converted at the decoder, a normally used first-type accompanying sound selectively made unused, for example, guide melody, is generated. In addition, by using the back left and back right surround audio signals, a normally unused second-type accompanying sound selectively used, for example, vocals, is generated. The first- and second-type accompanying sounds, together with the front left and front right main audio signals, are reproduced selectively. Consequently, a system that transmits surround sound using a plurality of channels can maintain compatibility with a surround system easily, when the plurality of channels are applied to special use, such as karaoke, not being restricted to surround use.