A method of encoding input data to generate corresponding encoded data includes: setting one or more values of a quality parameter for the plurality of data portions in a portion-specific manner; analysing the plurality of data portions and selecting at least one encoding method and at least two different quantization strengths for encoding the plurality of data portions, based upon a given value of the quality parameter set for the given data portion; encoding the plurality of data portions to generate corresponding encoded data portions, wherein at least two data portions are encoded by an encoding method and different quantization strengths, for a same value of the quality parameter for the at least two data portions; aggregating the encoded data portions to generate encoded data; and assembling information indicative of the at least two quantization strengths and the one or more values of the quality parameter into the encoded data.