Abstract: An audio encoder in which two or more preferably different encoders cooperate to generate a joint encoded audio signal. Encoding parameters of the two or more encoders are optimized in response to a measure of distortion of the joint encoded audio signal in accordance with a predetermined criterion. The distortion. measure is preferably a perceptual distortion measure. In one encoder embodiment comprising a sinusoidal and a waveform encoder, a constant total bit rate for each audio frame is distributed between the two encoders so as to minimize perceptual distortion for both the first and the second encoder. Other embodiments consider a set of encoding parameters that is larger than only those that minimize the perceptual distortion of the first encoder. In some embodiments, perceptual distortion may be minimized by optimizing encoding via optimizing entire encoding templates, i.e. a complex set of encoding parameters, for the separate encoders.

Abstract: The invention relates to an audio encoder and decoder and methods for audio encoding and decoding. In a preferred encoder embodiment an audio signal is encoded by deterministic encoder means to form a first encoded signal part. A spectrum of the audio signal is determined and represented by an excitation pattern, i.e. spectral values corresponding to human auditory filters, as a second encoded signal part. A masking curve is also extracted based on the excitation pattern, thus improving encoding efficiency in terms of bit rate. In a preferred decoder the first encoded signal part is decoded by deterministic decoder means. A noise generator uses the decoded first signal part together with the second signal part, i.e. the excitation pattern for the original audio signal, to generate a noise signal. The noise signal is then added to the first decoded signal part to form an output audio signal. At the decoder side the masking curve is also extracted based on the second encoded signal part, i.e.

Abstract: This invention relates to a method of determining (10) a second sound frame (20) representing sinusoidal components and an optionally third sound frame (30) representing a residual from a provided first sound frame, the method includes the steps of: determining a sinusoidal component in the first sound frame among non extracted components; determining an importance measure (40) for the first sound frame; extracting the sinusoidal component from the first sound frame, and incorporating the sinusoidal component in the second sound frame; and repeating said steps until the importance measure fulfils a stop criterion (50). In the method, the step of determining an importance measure for the first sound frame can be executed before said third step or it can be executed between said third and fourth step. Said method further includes the step of: setting the third sound frame to the first sound frame, when the importance measure fulfils said stop criterion.

Abstract: Coding of an audio signal (x) represented by a respective set of sampled signal values for each of a plurality of sequential segments is disclosed. The sampled signal values are used to determine sinusoidal components (CS) for each of the plurality of sequential segments. The sinusoidal components (CS) are subtracted from the sampled signal values to provide a set of values (s1, s2) representing afirst residual component (x3) of the audio signal. The first residual component (x3) is conditioned (18) to remove selected tonal components and to provide a set of values (s1?, s2?) representing a second residual component (x3?) of the audio signal. The second residual component is modelled (14) by determining noise parameters (CN) approximating the second residual component (x3?); and an encoded audio stream (AS) is generated including the noise parameters (CN) and the codes representing the sinusoidal components (CS).

Abstract: The invention provides coding (11) of an at least two-channel audio signal (L,R) by determining common frequencies (fcom) in the at least two channels (L,R) of the audio signal, which common frequencies occur in at least two of the at least two channels of the audio signal, and by representing respective sinusoidal components in respective channels at a given common frequency by a representation of the given common frequency (fcom) and a representation of respective amplitudes (A,?A) of the respective sinusoidal components at the given common frequency.