Apparatus and method for audio decoding supporting two spectral band replication modes

An apparatus for audio decoding according to an embodiment is provided. The apparatus comprises a decoding module for decoding a received encoded audio signal to obtain a decoded audio signal. Moreover, the apparatus comprises a first spectral band replication module for conducting spectral band replication depending on the decoded audio signal according to a first spectral band replication mode to obtain a spectral band replicated audio signal. Furthermore, the apparatus comprises a second spectral band replication module for conducting spectral band replication depending on the decoded audio signal according to a second spectral band replication mode to obtain the spectral band replicated audio signal, wherein the second spectral band replication mode is different from the first spectral band replication mode. To conduct the spectral band replication, the second spectral band replication module is configured to conduct one or more first processing operations and one or more second processing operations. The one or more second processing operations depend on the one or more first processing operations. The apparatus is configured to receive side information. The second spectral replication module exhibits a state which depends on the side information, the state being one of a deactivated state and one or more activated states. The second spectral band replication module is configured, when the second spectral band replication module is in the deactivated state, to not conduct any operation. Moreover, the second spectral band replication module is configured, when the second spectral band replication module is not in the deactivated state, to conduct at least one of the one or more first processing operations and the one or more second processing operations.