Fuente: Wipo "digitalization" The digital VTR includes an extractor, variable-length decoder, quantizer and variable-length encoder. The extractor receives digital data divided into blocks, and which is quantized and variable-length coded on a block-by-block basis. Portions of the digital data are encoded according to a first type of encodation, and other portions of the digital data are encoded according to a second type of encodation. The extractor identifies and extracts the digital data encoded according to the first type of encodation. The variable-length decoder variable-length decodes the extracted portions of the digital data, while the quantizer quantizes the decoded data output by the variable length decoder. The variable length encoder variable-length encodes the quantized decoded data to form special-playback data. Alternatively, a convertor converts the extracted portions of the digital data into variable-length coded data having different quantization steps to form the special-playback data.