Voiceage Corporation

Vaclav Eksler

A system and method code an object-based audio signal comprising audio objects in response to audio streams with associated metadata. In the system and method, an audio stream processor analyses the audio streams. A metadata processor is responsive to information on the audio streams from the analysis by the audio stream processor for coding the metadata. The metadata processor uses a logic for controlling a metadata coding bit-budget. An encoder codes the audio streams.

Method and system for coding metadata in audio streams and for flexible intra-object and inter-object bitrate adaptation

A method and device for detecting an attack in a sound signal to be coded wherein the sound signal is processed in successive frames each including a number of sub-frames. The device comprises a first-stage attack detector for detecting the attack in a last sub-frame of a current frame, and a second-stage attack detector for detecting the attack in one of the sub-frames of the current frame, including the sub-frames preceding the last sub-frame. No attack is detected when the current frame is not an active frame previously classified to be coded using a generic coding mode. A method and device for coding an attack in a sound signal are also provided. The coding device comprises the above mentioned attack detecting device and an encoder of the sub-frame comprising the detected attack using a transition coding mode using a glottal-shape codebook populated with glottal impulse shapes.

Methods and devices for detecting an attack in a sound signal to be coded and for coding the detected attack

A method and device for encoding a stereo sound signal comprise stereo encoders using stereo modes operating in time domain (TD), in frequency domain (FD) or in modified discrete Fourier transform (MDCT) domain. A controller controls switching between the TD, FD and MDCT stereo modes. Upon switching from one stereo mode to the other, the switching controller may (a) recalculate at least one length of down-processed/mixed signal in a current frame of the stereo sound signal, (b) reconstruct a down-processed/mixed signal and also other signals related to the other stereo mode in the current frame, (c) adapt data structures and/or memories for coding the stereo sound signal in the current frame using the other stereo mode, and/or (d) alter a TD stereo channel down-mixing to maintain a correct phase of left and right channels of the stereo sound signal. Corresponding stereo sound signal decoding method and device are described.

Switching between stereo coding modes in a multichannel sound codec

A system and method code an object-based audio signal comprising audio objects in response to audio streams with associated metadata. In the system and method, a metadata processor codes the metadata and generates information about bit-budgets for the coding of the metadata of the audio objects. An encoder codes the audio streams while a bit-budget allocator is responsive to the information about the bit-budgets for the coding of the metadata of the audio objects from the metadata processor to allocate bitrates for the coding of the audio streams by the encoder.

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Brno, Czechia

Vaclav Eksler