Voiceage Corporation

Voiceage Coproration

Voiceage Evs LLC

Voiceage Evs Gmbh & Co. Kg

Tommy Vaillancourt

Milan Jelinek

Redwan Salami

Vladimir Malenovsky

Philippe Gournay

Vladimir Malenowsky

A method and device selecting one of a first stereo mode and a second stereo mode for coding a stereo sound signal including a left channel and a right channel, comprises producing a first output indicative of a presence or absence of uncorrelated stereo content in the stereo sound signal, producing a second output indicative of a presence or absence of cross-talk in the stereo sound signal, calculating auxiliary parameters for use in selecting the stereo mode for coding a stereo sound signal, and selecting the stereo mode for coding a stereo sound signal in response to the first output, the second output and the auxiliary parameters.

Method and device for classification of uncorrelated stereo content, cross-talk detection, and stereo mode selection in a sound codec

A stereo sound decoding method and system decode left and right channels of a stereo sound signal, using received encoding parameters comprising encoding parameters of a primary channel, encoding parameters of a secondary channel, and a factor β. The primary channel encoding parameters comprise LP filter coefficients of the primary channel. The primary channel is decoded in response to the primary channel encoding parameters. The secondary channel is decoded using one of a plurality of coding models, wherein at least one of the coding models uses the primary channel LP filter coefficients to decode the secondary channel. The decoded primary and secondary channels are time domain up-mixed using the factor β to produce the decoded left and right channels of the stereo sound signal, wherein the factor β determines respective contributions of the primary and secondary channels upon production of the left and right channels.

Method and system for decoding left and right channels of a stereo sound signal

A stereo sound encoding method and system, for encoding left and right channels of a stereo sound signal, down mix the left and right channels of the stereo sound signal to produce primary and secondary channels and encode the primary and secondary channels. Encoding the primary channel and encoding the secondary channel comprise determining a first bit budget to encode the primary channel and a second bit budget to encode the secondary channel. If the second bit budget is sufficient, the secondary channel is encoded using a four subframes model and, if the second bit budget is insufficient for using the four subframes model, the secondary channel is encoded using a two subframes model.

Method and system for encoding left and right channels of a stereo sound signal selecting between two and four sub-frames models depending on the bit budget

A stereo sound encoding method and system for encoding left and right channels of a stereo sound signal, down mix the left and right channels of the stereo sound signal to produce primary and secondary channels, encode the primary channel, and encode the secondary channel. Encoding the secondary channel comprises analyzing coherence between coding parameters calculated during the secondary channel encoding and coding parameters calculated during the primary channel encoding to decide if the coding parameters calculated during the primary channel encoding are sufficiently close to the coding parameters calculated during the secondary channel encoding to be re-used during the secondary channel encoding.

Method and system for encoding a stereo sound signal using coding parameters of a primary channel to encode a secondary channel

A stereo sound decoding method and system decode left and right channels of a stereo sound signal, using received encoding parameters comprising encoding parameters of a primary channel, encoding parameters of a secondary channel, and a factor &#x3b2;. The primary channel encoding parameters comprise LP filter coefficients of the primary channel. The primary channel is decoded in response to the primary channel encoding parameters. The secondary channel is decoded using one of a plurality of coding models, wherein at least one of the coding models uses the primary channel LP filter coefficients to decode the secondary channel. The decoded primary and secondary channels are time domain up-mixed using the factor &#x3b2; to produce the decoded left and right channels of the stereo sound signal, wherein the factor &#x3b2; determines respective contributions of the primary and secondary channels upon production of the left and right channels.

A stereo sound signal encoding method and system for time domain down mixing right and left channels of an input stereo sound signal into primary and secondary channels, determine normalised correlations of the left channel and right channel in relation to a monophonic signal version of the sound. A long-term correlation difference is determined on the basis of the normalised correlation of the left channel and the normalized correlation of the right channel. The long-term correlation difference is converted into a factor &#x3b2;, and the left and right channels are mixed to produce the primary and secondary channels using the factor &#x3b2;, wherein the factor &#x3b2; determines respective contributions of the left and right channels upon production of the primary and secondary channels.

Method and system using a long-term correlation difference between left and right channels for time domain down mixing a stereo sound signal into primary and secondary channels

A method and system are implemented in a stereo sound signal encoding system for time domain down mixing right and left channels of an input stereo sound signal into primary and secondary channels. Correlation of the primary and secondary channels of previous frames is determined, and an out-of-phase condition of the left and right channels is detected based on the correlation of the primary and secondary channels of the previous frames. The left and right channels are time domain down mixed, as a function of the detection, to produce the primary and secondary channels using a factor &#x3b2;, wherein the factor &#x3b2; determines respective contributions of the left and right channels upon production of the primary and secondary channels.

Method and system for time domain down mixing a stereo sound signal into primary and secondary channels using detecting an out-of-phase condition of the left and right channels

A stereo sound signal encoding method and system for time domain down mixing right and left channels of an input stereo sound signal into primary and secondary channels, determine normalised correlations of the left channel and right channel in relation to a monophonic signal version of the sound. A long-term correlation difference is determined on the basis of the normalised correlation of the left channel and the normalised correlation of the right channel. The long-term correlation difference is converted into a factor &#x3b2;, and the left and right channels are mixed to produce the primary and secondary channels using the factor &#x3b2;, wherein the factor &#x3b2; determines respective contributions of the left and right channels upon production of the primary and secondary channels.

The present disclosure relates to a device and method for reducing quantization noise in a sound signal contained in a time-domain excitation decoded by a time-domain decoder. A future frame time-domain excitation is evaluated based on the decoded time-domain excitation. A concatenated time-domain excitation is produced from the decoded time-domain excitation of the time-domain excitation of the future frame and is converted into a frequency-domain excitation. A weighting mask is produced for retrieving spectral information lost in the quantization noise. The frequency-domain excitation is modified to increase spectral dynamics by application of the weighting mask. The modified frequency-domain excitation is converted into a modified time-domain excitation. The latter conversion is delay-less. In an embodiment, the weighting mask may be produced using time averaging or frequency averaging or a combination of time and frequency averaging of the frequency-domain excitation. The method and device can be used for improving music content rendering of linear-prediction (LP) based codecs.

Device and method for reducing quantization noise in a time-domain decoder

The present disclosure relates to a device and method for reducing quantization noise in a signal contained in a time-domain excitation decoded by a time-domain decoder. The decoded time-domain excitation is converted into a frequency-domain excitation. A weighting mask is produced for retrieving spectral information lost in the quantization noise. The frequency-domain excitation is modified to increase spectral dynamics by application of the weighting mask. The modified frequency-domain excitation is converted into a modified time-domain excitation. The method and device can be used for improving music content rendering of linear-prediction (LP) based codecs. Optionally, a synthesis of the decoded time-domain excitation may be classified into one of a first set of excitation categories and a second set of excitation categories, the second set including INACTIVE or UNVOICED categories, the first set including an OTHER category.

A method and device for modifying a synthesis of a time-domain excitation decoded by a time-domain decoder, wherein the synthesis of the decoded time-domain excitation is classified into one of a number of categories. The decoded time-domain excitation is converted into a frequency-domain excitation, and the frequency-domain excitation is modified as a function of the category in which the synthesis of the decoded time-domain excitation is classified. The modified frequency-domain excitation is converted into a modified time-domain excitation, and a synthesis filter is supplied with the modified time-domain excitation to produce a modified synthesis of the decoded time-domain excitation.

Non-speech content for low rate CELP decoder

A mixed time-domain/frequency-domain coding device and method for coding an input sound signal, wherein a time-domain excitation contribution is calculated in response to the input sound signal. A cut-off frequency for the time-domain excitation contribution is also calculated in response to the input sound signal, and a frequency extent of the time-domain excitation contribution is adjusted in relation to this cut-off frequency. Following calculation of a frequency-domain excitation contribution in response to the input sound signal, the adjusted time-domain excitation contribution and the frequency-domain excitation contribution are added to form a mixed time-domain/frequency-domain excitation constituting a coded version of the input sound signal. In the calculation of the time-domain excitation contribution, the input sound signal may be processed in successive frames of the input sound signal and a number of sub-frames to be used in a current frame may be calculated.

Coding generic audio signals at low bitrates and low delay

A device and method for estimating a tonal stability of a sound signal include: calculating a current residual spectrum of the sound signal; detecting peaks in the current residual spectrum; calculating a correlation map between the current residual spectrum and a previous residual spectrum for each detected peak; and calculating a long-term correlation map based on the calculated correlation map, the long-term correlation map being indicative of a tonal stability in the sound signal.

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Sherbrooke, Canada

Tommy Vaillancourt