Hi Tom, There is the other thing I need to confirm: It looks that the block's output buffer size can not be changed after its construction, right?
On Fri, Oct 12, 2012 at 10:12 AM, Tom Rondeau <t...@trondeau.com> wrote: > On Thu, Oct 11, 2012 at 7:41 PM, Alex Zhang <cingular.a...@gmail.com> > wrote: > > Let me take an example for my question. > > > > For some OFDM blocks, the io signature is determined by the fft length, > > during the constructing the block. However, sometimes, we need to adjust > the > > the fft length dynamically based on some physical environment or > computing > > environment. > > Hi Alex, > > I haven't thought about this too much, so my recollection of how > things work could be a bit off. But I'm pretty sure that the answer is > no, you cannot dynamically adjust this. You'd be messing too much with > the scheduler. > > The way that you can do it is to lock the flowgraph, swap out the > block in question with a new block that has the new parameters, and > unlock to restart the graph. But you are going to lose samples in the > buffers into the block that you're removing. > > This would actually be a great case for the event stream scheduler. > You could have different processing graphs that are selected based on > the state that you need. So you could populate graphs of different FFT > lengths and then dynamically select the right graph based on an event > when you detect a different length is required. This is still a > work-in-progress: https://github.com/osh/gr-eventstream. > > Tom > > > > On Thu, Oct 11, 2012 at 6:29 PM, Alex Zhang <cingular.a...@gmail.com> > wrote: > >> > >> Hi, > >> > >> I know it may not be possible in the current gnuradio blocks framework, > >> but I am still curious if it can be done. > >> When I write a signal processing block, the io signature could be > >> determined by some parameters. It is ok, if these parameters are fixed. > But > >> sometimes, especially in the adaptive system, I need to dynamically > update > >> these parameter, which result in the updating of io signature of the > blocks. > >> I can make the io_signature to be independent with the dynamic > parameters, > >> but it could be more convenient if the io signature can be adapted. Of > >> course, it is not easy, as the io signature change could impact the > upstream > >> and downstream. > >> > >> Thanks, > >> > >> -- > >> > >> Alex, > >> Dreams can come true – just believe. > >> > > > > > > > > -- > > > > Alex, > > Dreams can come true – just believe. > > > > > > _______________________________________________ > > Discuss-gnuradio mailing list > > Discuss-gnuradio@gnu.org > > https://lists.gnu.org/mailman/listinfo/discuss-gnuradio > > > -- Alex, *Dreams can come true – just believe.*
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