Apparatus and method for generating a level parameter and apparatus and method for generating a multi-channel representation
A parameter representation of a multi-channel signal having several original channels includes a parameter set, which, when used together with at least one down-mix channel allows a multi-channel reconstruction. An additional level parameter is calculated such that an energy of the at least one downmix channel weighted by the level parameter is equal to a sum of energies of the original channels. The additional level parameter is transmitted to a multi-channel reconstructor together with the parameter set or together with a down-mix channel. An apparatus for generating a multi-channel representation uses the level parameter to correct the energy of the at least one transmitted downmix channel before entering the down-mix signal into an upmixer or within the up-mixing process.
1. Apparatus for generating a level parameter within a parameter representation of a multi-channel signal having several original channels, the parameter representation comprising a parameter set, which, when used together with at least one down-mix channel, allows a multi-channel reconstruction, the apparatus comprising:
a level parameter calculator for calculating a level parameter, the level parameter being a level difference between a master down-mix and a parameter downmix, on which the parameter representation is based; and
an output interface for generating output data including the level parameter and the parameter set or the level parameter and the at least one down-mix channel.
2. Apparatus in accordance with claim 1 , in which the parameter representation includes a parameter set for each one of a number of frequency bands of the at least one down-mix channels, and
in which the parameter calculator is operative to calculate a level parameter for each one of the frequency bands.
3. Apparatus in accordance with claim 1 , in which the parameter representation includes a parameter set for a time period in a sequence of time periods of the at least one down-mix channel, and
in which the level parameter calculator is operative to calculate a level parameter for each time period in a sequence of time periods of the at least one downmix channel.
4. Apparatus in accordance with claim 1 , in which the output interface is operative to generate a scalable data stream, which includes, in a lower scaling layer, a first subgroup of parameters of the parameter set, which allows a reconstruction of the first subgroup of output channels,
which includes, in a higher scaling layer, a second subgroup of parameters of the parameter set, which allow, together with the first subgroup, a reconstruction of a second subgroup of output channels, and
in which the output interface is further operative to enter the level parameter into the lower scaling layer.
5. Apparatus in accordance with claim 1 , further comprising a parameter generator being formed to generate, as a first balance parameter, a left/right balance parameter, as a second balance parameter, a center balance parameter, as a third balance parameter, a front/back balance parameter, as a fourth balance parameter, a rear-left/right balance parameter, and as a fifth balance parameter, a low-frequency enhancement balance parameter.
6. Method of generating a level parameter within a parameter representation of a multi-channel signal having several original channels, the parameter representation comprising a parameter set, which, when used together with at least one down-mix channel, allows a multi-channel reconstruction, comprising:
calculating a level parameter, the level parameter being a level difference between a master down-mix and a parameter down-mix, on which the parameter representation is based; and
generating output data including the level parameter and the parameter set or the level parameter and the at least one down-mix channel.
7. A non-transitory storage medium having stored thereon a computer program having machine-readable instructions for performing a method of generating a level parameter within a parameter representation of a multi-channel signal having several original channels, the parameter representation comprising a parameter set, which, when used together with at least one downmix channel, allows a multi-channel reconstruction, the method comprising:
calculating a level parameter, the level parameter being a level difference between a master down-mix and a parameter down-mix, on which the parameter representation is based; and
generating output data including the level parameter and the parameter set or the level parameter and the at least one down-mix channel,
when running on a computer.