Re: [Discuss-gnuradio] OOT: Output does not update fast. Buffer size?

Sample rate in software is just a number used in some equations to get meaningful signals. It is *not* the rate that things are going through the flowgraph. There are 8192 items because 8192 items happens to make a nicely aligned buffer size.

You're not working on a real-time system or with real-time software, so you can't expect things like "1 input per second".

On Thu, May 11, 2017 at 6:12 AM, Ali <03dober@gmail.com> wrote:

Hi to all,

I created my own OOT block. It has 6 inputs and 2 outputs and all are type of float. I am using Signal Source block and sending constant signals with different amplitudes at each input port.

When I run, the the GRC file and change the one of the inputs, outputs changes after some time(~5 seconds). To examine the problem, I am printing the following variables on the screen: 

noutput_items, input1[1], input1[noutput_items], output1[1], output1[noutput_items] 

...

8192, 44, 44, 1, 1   >>> Input1 is 44 and outputs are 1

8192, 44, 44, 1, 1   >>> Input 1 is still 44

8192, 44, 26, 1, 1   >>> I changed the input1 to 26. Note that input[1] is still 44. input[noutput_items] is 26 but output[noutput_items] is also 1!

8192, 26, 26, 1, 1   >>> The content of input1 is all 26, but the output is still 1!

8192, 26, 26, 1, 1   >>> The output is still 1!

8192, 26, 26, 2, 2   >>> Now the correct output is found!

.... 

First of all, why the dimension of input and output is 8192(sometimes 8191)? 

samp_rate defined for Signal Source block is smaller than 8192. I am using 1, 100 or 1000. But as you can see noutput_items is 8192. How there can be 8192 inputs if the sample rate is for example 10?

My module content is like the following:

------------------------------------

int myfunction_impl::general_work(...)

{

const float *input1 = ..

..

for (int i=; i<noutput_items; i++)

{

my_function(input1[i],...,&output1[i],&output2[i])

}

consume_each(noutput_items);

return noutput_items;

}

--------------------------------------

In short, I want that one input comes per second(sampling rate 1) and one output is out and displayed. 

Regards,

Ali

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