A Dynamic Embedding Codec for Multiple Generations Compression
Frank Kurth, Viktor Hassenrik · 2000
We present an audio codec for multiple, i.e., cascaded, lossy compression without degeneration of perceptual quality. Our coding scheme is based on a previously reported psychoacoustic embedding strategy which allows to transfer encoding information to all subsequent codecs in a cascade. In this paper, we develop a new dynamic embedding scheme which allows an optimal exploitation of a signal's perceptual embedding capacity. As opposed to previous methods, our approach allows to overcome embedding capacity problems and possible signal distortions. Morover, it allows the realization of a new embedding strategy which guarantees the perfect reconstruction of the first generation signal after an arbitrary number of encoding and decoding steps. In the presented MPEG-1 based codec implementations the dynamic embedding scheme is realized by a specific bit reservoir technique.