Coding of an information signal

Abstract

The problem of transients can be addressed satisfactorily and a further decoding delay can be reduced for this if use is made of a new SBR frame class in which the frame limits (902a, 902b) are not shifted, that is to say the grid limits are still synchronized with the frame limits (902a, 902b), but in which a statement of the transient position is also used as a syntax element in order to be used, within the frames of this new frame class, to determine the grid limits within these frames at the coder and / or decoder end.

Description

technical field [0001] The invention relates to information signal coding, such as audio coding, and in this context in particular SBR (Speed ​​Band Replication) coding. Background technique [0002] In the context of encoding audio signals in applications with very small available bit rates, it is known to use SBR techniques for encoding. Only the low frequency part is fully coded, ie with sufficient temporal and spatial resolution. For the high frequency part, only the spectral envelope or the envelope of the spectral time curve of the audio signal is detected and encoded. On the decoder side, the low frequency components are obtained from the encoded signal and are then used to reconstruct or "copy" the high frequency components from the signal. However, in order to adapt the energy of the pre-reconstructed high-frequency part to the actual energy in the high-frequency part of the original audio signal, the pre-reconstructed high-frequency part is processed at the decod...

AI Technical Summary

Problems solved by technology

Although this prevents pre-echo, this scheme is not suitable for applications requiring short delay times

Furthermore, the number of bits required to transmit an SBR frame is relatively high in the above standard

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