Orange

Koninklijke Philips Corporation N.v.

France Telecom

Stephane Ragot

Magdalena Kaniewska

Balazs Kovesi

Julien Faure

Bertrand Fatus

Marc Emerit

Najmeddine Majed

Jerome Dufour

David Virette

Jerome Daniel

Pierre Berthet

Thi Minh Nguyet Hoang

Minh Tri Vo

A method of parametric coding of a multichannel digital audio signal including coding a signal arising from a channels reduction processing applied to the multichannel signal and coding spatialization information of the multichannel signal. The method includes the following acts: extraction of a plurality of items of spatialization information of the multichannel signal; obtaining at least one representation model of the extracted spatialization information; determination of at least one angle parameter of a model obtained; coding the at least one determined angle parameter so as to code the spatialization information extracted during the coding of spatialization information. Also provided are a method for decoding such a coded signal and corresponding coding and decoding devices.

Optimized coding and decoding of spatialization information for the parametric coding and decoding of a multichannel audio signal

A method, receiver device and terminal for signaling an adaptation request to adapt a coding/decoding of real-time signals of a real-time communication session, from a receiver device to a sender device. The method is such that the adaptation request relates to a demand for aggregation and/or redundancy of frames, that it is generated according to the existence of a signaling parameter arising from a phase of negotiation of codecs used during initialization of the communication session and in that it is transported via a real-time protocol of RTP type.

Signaling of a request to adapt a voice-over-IP communication session

A method for decoding a digital signal encoded using predictive coding and transform coding, comprising the following steps: predictive decoding of a preceding frame of the digital signal, encoded by a set of predictive coding parameters; detecting the loss of a current frame of the encoded digital signal; generating by prediction, from at least one predictive coding parameter encoding the preceding frame, a frame for replacing the current frame; generating by prediction, from at least one predictive coding parameter encoding the preceding frame, an additional segment of digital signal; temporarily storing said additional segment of digital signal.

Frame loss management in an FD/LPD transition context

A method for adapting an encoding bitrate of real-time signals of a real-time communication session between sender devices and receiver devices of communication terminals. A sender device includes a multi-bitrate encoder using a set of discrete bitrates. The method includes a test step of increasing the encoding bitrate at the sender device by transmitting at least one redundant packet according to selected transmission parameters. A method is also provided for determining a request to adapt the encoding bitrate of real-time signals in order to implement a test of increasing the encoding bitrate at the sender device by transmitting at least one redundant packet according to selected transmission parameters. A sender device and a receiver device implementing the methods are provides as well as a terminal containing these devices.

Bitrate adaptation of a voice-over-IP communication session

A method is provided for extending the frequency band of an audio signal during a decoding or improvement process. The method includes obtaining the decoded signal in a first frequency band, referred to as a low band. Tonal components and a surround signal are extracted from the signal from the low-band signal, and the tonal components and the surround signal are combined by adaptive mixing using energy-level control factors to obtain an audio signal, referred to as a combined signal. The low-band decoded signal before the extraction step or the combined signal after the combination step are extended over at least one second frequency band which is higher than the first frequency band. Also proved are a frequency-band extension device which implements the described method and a decoder including a device of this type.

Frequency band extension in an audio signal decoder

A method of determining a distribution of bits for coding a transition frame, said method being implemented in a coder/decoder for coding/decoding a digital signal, the transition frame being preceded by a predictive coded preceding frame, coding the transition frame comprising transform coding and predictive coding a single sub-frame of the transition frame, the method comprising the following steps: assigning a bit rate for predictive coding the transition sub-frame, said bit rate being equal to the minimum between the bit rate for transform coding the transition frame and a first predetermined bit rate value; determining a first number of bits allocated for predictive coding the transition sub-frame for said bit rate; and calculating a second number of bits allocated for transform coding the transition frame from the first number of bits and a number of bits available for coding the transition frame.

Determining a budget for LPD/FD transition frame encoding

A method and device are provided for determining an optimized scale factor to be applied to an excitation signal or a filter during a process for frequency band extension of an audio frequency signal. The band extension process includes decoding or extracting, in a first frequency band, an excitation signal and parameters of the first frequency band including coefficients of a linear prediction filter, generating an excitation signal extending over at least one second frequency band, filtering using a linear prediction filter for the second frequency band. The determination method includes determining an additional linear prediction filter, of a lower order than that of the linear prediction filter of the first frequency band, the coefficients of the additional filter being obtained from the parameters decoded or extracted from the first frequency and calculating the optimized scale factor as a function of at least the coefficients of the additional filter.

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Lannion, France

Stephane Ragot