Re: [Discuss-gnuradio] Throttle block form wav files

[Kevin Reid]

On Sep 7, 2015, at 5:42, Murray Thomson <address@hidden> wrote:

>> 1. Using some method to force the wav source and audio source to match 
>> sample rates. Specifically, you could use a “Multiply by Matrix” block to 
>> replace the function of the Selector entirely: give it a matrix value of 
>> either ((1, 0),) or ((0, 1),) to select just one input.
>  
> Can I make a multiply to matrix block have several inputs and one only 
> output? If not, I was thinking on multiplying one of them by a constant block 
> zero and then adding both outputs. Would this be a valid workaround?

The number of inputs and outputs are determined by the dimensions of the matrix 
value entered. If you put in ((0, 1,),) with the comma (actually, I just 
remembered you can write [[0, 1]] as well and you don't have to worry about the 
extra comma (blame Python for that)) then it will have 2 inputs and 1 output. 
And, for example, if you wrote [[0], [1]], then it would have 1 input and 2 
outputs.

By the way, you can of course enter any numeric values to scale the inputs as 
you like, so for example you could use [[0, 0]] as a “mute” mode, or enter an 
arbitrary number as a gain control, if you wanted one.

(If you did have an extra output that you couldn't get rid of, a null sink 
would be simplest there.)

-- 
Kevin Reid                                  <http://switchb.org/kpreid/>