The present invention relates to an improvement in frame based codecs and in particular to a en encoding/decoding method, an coder/decoder (codec) and a radio communication device. The signal provided at the output of the improved frame based codec comprises frames of regular duration though the start of a frame is time offset in relation to the end of the preceding frame. The time offset varies from frame to frame. The output signal from the improved codec has no fixed framing grid. Time offsets may be positive, in which case two successive frames are separated with a gap in which substitution signals are inserted, or negative in which case two successive frames are overlapping. As substitution signals an extrapolation of the signal in a preceding frame, an interpolation of signals from a preceding frame and a following frame or a directly coded signal may be used. Negative offset makes it possible to capture transients in the signal to be encoded. The present invention relates to an improvement in frame based codecs and in particular to a en encoding/decoding method, an coder/decoder (codec) and a radio communication device. The signal provided at the output of the improved frame based codec comprises frames of regular duration though the start of a frame is time offset in relation to the end of the preceding frame. The time offset varies from frame to frame. The output signal from the improved codec has no fixed framing grid. Time offsets may be positive, in which case two successive frames are separated with a gap in which substitution signals are inserted, or negative in which case two successive frames are overlapping. As substitution signals an extrapolation of the signal in a preceding frame, an interpolation of signals from a preceding frame and a following frame or a directly coded signal may be used. Negative offset makes it possible to capture transients in the signal to be encoded.