Dolby International Ab

Dolby Laboratories Licensing Corporation

Fraunhofer-gesellschaft Zur Foerderung Der Angewandten Forschung E.v.

Dolby Sweden Ab

Barbara Resch

Lars Villemoes

Kristofer Kjörling

Kristofer Kjorling

Jonas Engdegard

Heiko Purnhagen

Arijit Biswas

Regunathan Radhakrishnan

Kristofer Kjoerling

Juergen Herre

Johannes Hilpert

Andreas Hoelzer

Per Hedelin

Cornelia Falch

Leonid Terentiev

Jonas Engdegård

Lars Villemors

Lars Falck Villemoes

Per Henrik Hedelin

In some embodiments, a pitch filter for filtering a preliminary audio signal generated from an audio bitstream is disclosed. The pitch filter has an operating mode selected from one of either: (i) an active mode where the preliminary audio signal is filtered using filtering information to obtain a filtered audio signal, and (ii) an inactive mode where the pitch filter is disabled. The preliminary audio signal is generated in an audio encoder or audio decoder having a coding mode selected from at least two distinct coding modes, and the pitch filter is capable of being selectively operated in either the active mode or the inactive mode while operating in the coding mode based on control information.

Post filter for audio signals

Pitch filter for audio signals

Selective bass post filter

In one aspect, the invention provides an audio encoding method characterized by a decision being made as to whether the device which will decode the resulting bit stream should apply post filtering including attenuation of interharmonic noise. Hence, the decision whether to use the post filter, which is encoded in the bit stream, is taken separately from the decision as to the most suitable coding mode. In another aspect, there is provided an audio decoding method with a decoding step followed by a post-filtering step, including interharmonic noise attenuation, and being characterized in a step of disabling the post filter in accordance with post filtering information encoded in the bit stream signal. Such a method is well suited for mixed-origin audio signals by virtue of its capability to deactivate the post filter in dependence of the post filtering information only, hence independently of factors such as the current coding mode.

Selective post filter

An audio object coder for generating an encoded object signal using a plurality of audio objects includes a downmix information generator for generating downmix information indicating a distribution of the plurality of audio objects into at least two downmix channels, an audio object parameter generator for generating object parameters for the audio objects, and an output interface for generating the imported audio output signal using the downmix information and the object parameters. An audio synthesizer uses the downmix information for generating output data usable for creating a plurality of output channels of the predefined audio output configuration.

Enhanced coding and parameter representation of multichannel downmixed object coding

In one embodiment, an audio decoder for decoding an encoded audio bitstream is disclosed. The audio decoder is capable of being operated in at least three different decoding modes. The audio decoder includes a demultiplexer for obtaining audio data and control information from the encoded audio bitstream. The audio decoder also includes a first audio decoder configured to operate in a first decoding mode using a first decoding technique and a second audio decoder configured to operate in a second decoding mode using a second decoding technique. The audio decoder also includes a pitch predictor integrated into the second audio decoder. The pitch predictor includes a long-term prediction filter and a short-term prediction filter. The audio decoder further includes a selector for selecting one of the at least three different decoding modes based on at least some of the control information.

Audio encoder and decoder with pitch prediction

Disclosed is a method, apparatus and non-transitory computer readable storage medium, which is configured to examine an input audio signal to determine an estimated pitch period associated with a detection criterion, encode the filtered audio signal to generate a compressed audio bit stream, decode the compressed audio bit stream to generate a decoded audio signal and adaptively filtering the decoded audio signal to produce an output audio signal, wherein adaptively filtering the decoded audio signal comprises filtering each of a plurality of segments of the decoded audio signal in a manner that is dependent upon the estimated pitch period associated therewith, and wherein a pitch-based post-filter operates to shape noise components located between harmonics of the input audio signal.

Post filter

In one embodiment, an audio decoder for decoding an audio bitstream is disclosed. The decoder includes a first decoding module adapted to operate in a first coding mode and a second decoding module adapted to operate in a second coding mode, the second coding mode being different from the first coding mode. The decoder further includes a pitch filter in either the first coding mode or the second coding mode, the pitch filter adapted to filter a preliminary audio signal generated by the first decoding module or the second decoding module to obtain a filtered signal. The pitch filter is selectively enabled or disabled based on a value of a first parameter encoded in the audio bitstream, the first parameter being distinct from a second parameter encoded in the audio bitstream, the second parameter specifying a current coding mode of the audio decoder.

Audio encoder and decoder with multiple coding modes

Techniques for scene change detection around seed points in media data are provided. Media features of many different types may be extracted from the media data. One or more statistical patterns of media features in a plurality of time-wise intervals around a plurality of seed time points of the media data may be determined using one or more types of features extractable from the media data. At least one of the one or more types of features comprises a type of features that captures structural properties, tonality including harmony and melody, timbre, rhythm, loudness, stereo mix, or a quantity of sound sources as related to the media data. A plurality of beginning scene change points and a plurality of ending scene change points in the media data may be detected, based on the one or more statistical patterns, for the plurality of seed time points in the media data.

Scene change detection around a set of seed points in media data

Growing community of inventors

Solna, Sweden

Barbara Resch