The invention concerns a method of determining at least one parameter for encoding multimedia digital data organized in elementary units of data intended to be encoded according to at least one encoding mode, wherein said method comprises the following steps:--determining at least one elementary magnitude which is representative of the resources needed for decoding each elementary data unit encoded according to a different encoding mode,--determining at least one total magnitude which is representative of the resources needed for decoding a plurality of elementary data units encoded as a function on the one hand of the at least one elementary magnitude previously determined and on the other hand the number of elementary units encoded according to each of the encoding modes,--deciding with regard to the determination of at least one data encoding parameter as a function of the at least one total magnitude previously determined and a predetermined magnitude.