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Abstract

The present document relates to methods and apparatus for audio coding. In particular, the present document relates to methods and apparatus for enhanced block switching and/or bit allocation in audio coding of transient-tonal signals. A method of encoding samples of an audio signal comprises determining a first measure indicative of transient characteristics of the audio signal, determining a second measure indicative of tonal characteristics of the audio signal, selecting a transform length for the audio signal on the basis of the first measure and the second measure, and applying a time-frequency transform to a block of samples of the audio signal in accordance with the selected transform length, to thereby obtain a block of frequency coefficients corresponding to the block of samples of the audio signal. Another method of encoding samples of an audio signal comprises applying a time-frequency transform to the audio signal in accordance with a selected transform length, to thereby obtain a sequence of blocks of frequency coefficients, wherein each block of frequency coefficients among said sequence corresponds to a respective block of samples of the audio signal, determining a measure of tonal characteristics for a frequency band of the audio signal based on the blocks of frequency components among said sequence, selecting, for the blocks of frequency coefficients among said sequence, a quantization step size for the frequency coefficients in said frequency band on the basis of said measure of tonal characteristics, and quantizing, for the blocks of frequency coefficients among said sequence, the frequency coefficients in said frequency band in accordance with the selected quantization step size.

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