On Wed, Feb 06, 2008 at 11:46:18AM -0500, Brian Padalino wrote: > On Feb 6, 2008 10:42 AM, Eric Blossom <[EMAIL PROTECTED]> wrote: > > The history mechanism does work as it was designed to do. For a > > history setting of N, it effectively preloads the first buffer with > > N-1 zeros. > > So just to be clear, if we have 2 calls to work() where we set the > history to 5 taps for a FIR filter. The first input: > > [ 0 0 0 0 1 2 3 4 5 ] > > Will have 5 input items and produce 5 output items. If we then call > work() again with 5 more input items, are we looking at: > > [ 2 3 4 5 6 7 8 9 10 ] <-- This
> - or - > > [ 0 0 0 0 6 7 8 9 10 ] > > In essence, who's job is it to maintain state in the filter? > > Brian The way we've implemented the FIR, the state is all implicit in the input. When using history == ntaps, the standard housekeeping handles it for you. forecast ensures that you've got enough valid input for the given number of output samples. Outside of a bit of magic that preloads the zeros before the first time call, the rest of it is handled in forecast. Eric _______________________________________________ Discuss-gnuradio mailing list [email protected] http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
