A transform-based speech encoder (100, 170) configured to encode a speech signal into a bitstream; the encoder comprising - a framing unit configured to receive a plurality of sequential blocks of transform coefficients comprising a current block and one or more previous blocks; wherein the plurality of sequential blocks is indicative of samples of the speech signal; - a flattening unit configured to determine a current block and one or more previous blocks of flattened transform coefficients by flattening the corresponding current block and the one or more previous blocks of transform coefficients using a corresponding current block envelope and corresponding one or more previous block envelopes, respectively; - a predictor configured to determine a current block of estimated flattened transform coefficients based on one or more previous blocks of reconstructed transform coefficients and based on one or more predictor parameters; wherein the one or more previous blocks of reconstructed transform coefficients have been derived from the one or more previous blocks of flattened transform coefficients, respectively; wherein the predictor comprises - a model-based predictor using a signal model; wherein the signal model comprises one or more sinusoidal model components; wherein the signal model comprises one or more model parameters; and the one or more predictor parameters are indicative of the one or more model parameters; - an extractor configured to determine a current block of estimated transform coefficients based on the one or more previous blocks of reconstructed transform coefficients and based on the one or more predictor parameters; and - a spectral shaper configured to determine the current block of estimated flattened transform coefficients based on the current block of estimated transform coefficients, based on the one or more previous block envelopes and based on the one or more predictor parameters; and - a difference unit configured to determine a current block of prediction error coefficients based on the current block of flattened transform coefficients and based on the current block of estimated flattened transform coefficients; wherein the bitstream is determined based on the current block of prediction error coefficients. - a framing unit configured to receive a plurality of sequential blocks of transform coefficients comprising a current block and one or more previous blocks; wherein the plurality of sequential blocks is indicative of samples of the speech signal; - a flattening unit configured to determine a current block and one or more previous blocks of flattened transform coefficients by flattening the corresponding current block and the one or more previous blocks of transform coefficients using a corresponding current block envelope and corresponding one or more previous block envelopes, respectively; - a predictor configured to determine a current block of estimated flattened transform coefficients based on one or more previous blocks of reconstructed transform coefficients and based on one or more predictor parameters; wherein the one or more previous blocks of reconstructed transform coefficients have been derived from the one or more previous blocks of flattened transform coefficients, respectively; wherein the predictor comprises - a model-based predictor using a signal model; wherein the signal model comprises one or more sinusoidal model components; wherein the signal model comprises one or more model parameters; and the one or more predictor parameters are indicative of the one or more model parameters; - an extractor configured to determine a current block of estimated transform coefficients based on the one or more previous blocks of reconstructed transform coefficients and based on the one or more predictor parameters; and - a spectral shaper configured to determine the current block of estimated flattened transform coefficients based on the current block of estimated transform coefficients, based on the one or more previous block envelopes and based on the one or more predictor parameters; and - a difference unit configured to determine a current block of prediction error coefficients based on the current block of flattened transform coefficients and based on the current block of estimated flattened transform coefficients; wherein the bitstream is determined based on the current block of prediction error coefficients.