DECODING SOUND PARAMETERS
A device ( 1 ) for producing sound samples from sound parameters representing sound components comprises a transient synthesis unit ( 14 ) for synthesizing transient sound components from transient sound parameters contained in each frame. To increase the efficiency of the synthesis, a transient selection unit ( 11 ) is arranged for selecting only a single transient sound component per frame. Additionally, the device may be arranged for producing fewer sinusoidal sound components if a transient is produced. Transform domain coefficients may be convolved with a transform domain representation of a time window representation, the number of resulting transform domain coefficients being controlled to further enhance the efficiency of the synthesis.
1 . A device for producing sound samples from sound parameters representing sound components, the device comprising:
at least one selection unit for receiving frames containing sound parameters which represent sound components and for selecting, for each frame, a limited number of sound components, and
at least one synthesis unit for synthesizing any selected sound components from their parameters.
2 . The device according to claim 1 , comprising a transient selection unit for selecting, for each frame containing transient sound components, a single transient sound component, and a transient synthesis unit for synthesizing any selected transient sound components from their parameters.
3 . The device according to claim 2 , wherein the transient selection unit is provided with means for selecting the transient sound component having the largest energy content.
4 . The device according to claim 2 , wherein the transient synthesis unit is provided with a discontinuation unit for discontinuing a transient sound component of a previous frame when synthesizing a transient sound component in the present frame.
5 . The device according to claim 1 , comprising a sinusoidal selection unit for selecting, for each frame, one or more sinusoidal sound components, and a sinusoidal synthesis unit for synthesizing selected sinusoidal sound components from their parameters.
6 . The device according to claim 2 , wherein the sinusoidal selection unit reduces the number of selected sinusoidal components if the transient selection unit selects a transient component for the same frame.
7 . The device according to claim 5 , further comprising an inverse transform unit.
8 . The device according to claim 5 , wherein the sinusoidal selection unit comprise a convolution unit for convolving the transform domain coefficients with a transform domain representation of a time window, and wherein the sinusoidal selection unit is preferably also provided with a coefficient limiting unit for limiting the number of additional transform domain coefficients resulting from the convolution.
9 . The device according to claim 8 , wherein the coefficient limiting unit limits the number of additional transform domain coefficient in a frame in dependence on the original number of sound parameters in the frame, preferably per frequency band.
10 . The device according to claim 1 , comprising a noise selection unit for selecting, for each frame, noise sound components to be synthesized, and a noise synthesis unit for synthesizing noise sound components from their parameters.
11 . A consumer device comprising a device according to claim 1 .
12 . A sound system comprising a device according to claim 1 .
13 . A method of producing sound samples from sound parameters representing transient sound components and other sound components, the method comprising the steps of:
receiving frames containing sound parameters which represent sound components,
selecting, for each frame, a limited number of sound components, and
synthesizing any selected sound components from their parameters.
14 . The method according to claim 13 , wherein the selecting step involves selecting, for each frame, a single transient sound component, and wherein the synthesizing step involves synthesizing any selected transient sound components from their parameters.
15 . The method according to claim 14 , wherein the selecting step involves selecting the transient sound component having the largest energy content.
16 . The method according to claim 14 , wherein the synthesizing step involves discontinuing a transient sound component of a previous frame when synthesizing a transient sound component in the present frame.
17 . The method according to claim 13 , further comprising the step of synthesizing sinusoidal sound components from sinusoidal sound parameters contained in a frame, and selecting sinusoidal sound components prior to the synthesis.
18 . The method according to claim 14 , further comprising the step of reducing the number of selected sinusoidal components if a transient sound component for the same frame is produced.
19 . The method according to claim 13 , wherein the sound parameters represent transform domain coefficients, the method preferably further comprising the step of inversely transforming said transform domain coefficients.
20 . The method according to claim 19 , further comprising the step of convolving the transform domain coefficients with a transform domain representation of a time window, and preferably limiting the number of additional transform domain coefficients resulting from the convolution.
21 . The method according to claim 13 , further comprising the steps of synthesizing noise sound components from noise sound parameters contained in a frame, and selecting noise sound components prior to the synthesis.
22 . A computer program product for carrying out the method according to claim 13 .