Time-scale modification of signals
AssigneeKoninklijke Philips Electronics N.V.
InventorsRakesh Taori, Andreas Johannes Gerrits, Dzevdet Burazerovic
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Abstract
Techniques utilising Time Scale Modification (TSM) of signals are described. The signal is analysed and divided into frames of similar signal types. Techniques specific to the signal type are then applied to the frames thereby optimising the modification process. The method of the present invention enables TSM of different audio signal parts to be realized using different methods, and a system for effecting said method is also described.
Claims16
A method of time scale modifying a signal, the method comprising the acts of:
- defining individual frame segments within the signal,
- analyzing the individual frame segments to determine a signal type in each frame segment,
- applying a first algorithm to a determined first signal type and a second different algorithm to a determined second signal type, wherein the first and second algorithms are time scale modification algorithms and the method is used for time scale modification of the signal, and
- wherein the first signal type is a voiced signal segment and wherein the second signal type is an un-voiced signal segment,
- splitting the un-voiced speech signal in a first portion and a second portion, and
- inserting noise in between the first portion and the second portion to obtain a time scale expanded signal,
- wherein the noise is synthetic noise with a spectral shape equivalent to the spectral shape of the first and second portions of the signal and wherein the inserted noise is excised from the middle of a previously synthesized noise sequence.
A time scale modifying device adapted to modify a signal so as to effect the formation of a time scale modified signal comprising:
- a) means for determining different signal types within frames of the signal,
- b) means for applying a first time scale modification algorithm to frames having a first determined signal type and a second different time scale modification algorithm to frames having a second determined signal type,
- wherein the first signal type is a voiced signal segment and wherein the second signal type is an un-voiced signal segment,
- means for splitting the un-voiced speech signal in a first portion and a second portion, and
- means for inserting noise in between the first portion and the second portion to obtain a time scale expanded signal,
- wherein the noise is synthetic noise with a spectral shape equivalent to the spectral shape of the first and second portions of the signal and wherein the inserted noise is excised from the middle of a previously synthesized noise sequence.
Dependencies are inferred from the claim text.