I need to process frame subbands before synthesis occurs. Libmad conveniently makes them available through its filtering feature. However the information around filtering is rather limited. I have studied the source code in filter.c and (think that I) have read all the relevant articles in this list, so I understand the basics, however I do have a few more questions:
1. What are the units and range of values for each subband? Must these values be scaled before they can be used?
[I saw in a list article that subband values range from -MAD_F_ONE to MAD_F_ONE. Have these values been scaled?]
2. What are the frequency ranges that each subband covers?
Many thanks.
Bill