1. An audio and video data processor, comprising a non-transitory computer readable medium having thereon: a selector for selecting from a first audio data stream at least a portion thereof, said first audio data stream being synchronized with corresponding visual events in a moving picture video data stream; an audio feature analyzer for abstracting from said selected portion of said first audio data stream a stream of time-varying features representative of time-varying acoustic features and for abstracting corresponding time-varying features from an input second audio data stream; a timing analysis and waveform editing processor adapted to determine timing differences between said stream of time-varying features and said corresponding time-varying features and to utilize said timing differences to edit said input second audio data stream to produce an edited input second audio data stream having acoustic features aligned with the acoustic features of said selected portion of said first audio data stream; and a playback control module adapted to control running of said synchronized first audio data and video data streams with said edited input second audio data stream such that said edited input second audio data stream replaces said selected portion and is synchronized with said corresponding visual events in said video data stream.