Re: [Discuss-gnuradio] SSB Phasing - working at last.

[Eric Blossom]

On Sun, Feb 27, 2005 at 11:22:53AM +1030, Daniel O'Connor wrote:
> On Sun, 27 Feb 2005 05:04, Eric Blossom wrote:
>
> > You'd be depending on unspecified and HIGHLY subject-to-change
> > implementation details.  If you are counting on a delay and a parallel
> > filter to stay in phase, they need to be implemented in the same C++
> > block.  We don't make any guarantees about the amount of buffering
> > between blocks and whether it stays constant over time.
> >
> > Is this a scary enough disclaimer?
> 
> Ahh right, I didn't realise the buffering between blocks was allowed to 
> change..

FYI, my disclaimer was probably a bit over the top.

I'm not trying to break anything that works, but I do want to leave us
some implementation flexibility for the future.  It's unlikely that
the buffering would change at runtime unless your application changed
something such as number of taps in a filter, amount of "history" for
a particular block, change in interpolation or decimation factors, etc.

All that said, in the particular case of a delay line in parallel with
a filter, the safe answer is a general block that pairs the filter with
a delay line.

Eric