Upsampling means, that the sampling rate increases. So if you have a 250 Hz signal, and create a 22000 Hz signal from it, that is - by definition - upsampling.
That's *exactly* what upsampling means... You insert new samples between the original ones, and interpolate between them (using whatever interpolation filter of your preference). And that is often used synonymously with 'oversampling', and that's what happens in an "oversampled" D/A converter. (Though 'oversampling' has a different meaning in A/D context.) -P _______________________________________________ music-dsp mailing list music-dsp@music.columbia.edu https://lists.columbia.edu/mailman/listinfo/music-dsp
