# Re: new stream selector block in gr-basic

**URL:** <https://www.ruby-forum.com/t/re-new-stream-selector-block-in-gr-basic/213998>\
**Category:** GNU Radio\
**Created:** [November 18, 2011, 11:02am UTC](https://www.ruby-forum.com/t/re-new-stream-selector-block-in-gr-basic/213998 "2011-11-18T11:02:50Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![luislavena](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/l/0ea827/32.png) [@luislavena](https://www.ruby-forum.com/u/luislavena)\
**Post date:** [November 18, 2011, 11:02am UTC](https://www.ruby-forum.com/t/re-new-stream-selector-block-in-gr-basic/213998/1 "2011-11-18T11:02:50Z")

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Hi,

This is great work.

I updated my Gnu Radio to the latest code using Marcus build-gnuradio  
script but I did not get this new selector block.

Can someone please explain me how can I integrate this new selector  
block into my gnuradio/GRC installation on Ubuntu.

Thanks,

Khalid.

Josh B. wrote in post #1031824:\> Hey list,\>\> I have noticed that  
many user’s have found the need to mux a stream.\> Either to  
dynamically select an alternative data source or to mux an\> output to  
an alternative sink like a different demodulator.\>\> Currently, GRC has  
come with selector (and valve). These blocks\> implement stream muxing  
by dynamically reconfiguring the flow graph.\> However, this method  
seems to be slow and error prone.\>\> So, I have created a stream  
selector block in gr-basic. Stream selector\> has N inputs and M  
outputs and allows the user to dynamically change the\> stream routing  
without flow graph reconfiguration.\>\> The good:\> - the switchover is  
immediate\> - no lock/unlock start/stop, so no errors\> - unused inputs  
can be put into blocking or consume mode\>\> The bad:\> - The  
post-reconfiguration overhead is an extra memcpy from source port\> to  
destination port\>\> The work is here, and grc demo attached:\>  
[http://gnuradio.org/cgit/jblum.git/tree/gr-basic/include/gr\_basic\_stream\_selector.h?h=gr\_basic](http://gnuradio.org/cgit/jblum.git/tree/gr-basic/include/gr_basic_stream_selector.h?h=gr_basic)\>\>  
-Josh

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**Author:** ![khalid\_j](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/k/53a042/32.png) [@khalid\_j](https://www.ruby-forum.com/u/khalid_j)\
**Post date:** [November 18, 2011, 4:13pm UTC](https://www.ruby-forum.com/t/re-new-stream-selector-block-in-gr-basic/213998/2 "2011-11-18T16:13:11Z")

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On 11/18/2011 02:01 AM, Khalid J. wrote:

> Hi,
> 
> This is great work.
> 
> I updated my Gnu Radio to the latest code using Marcus build-gnuradio  
> script but I did not get this new selector block.

The work has not been merged into the official gnuradio master branch.

> Can someone please explain me how can I integrate this new selector  
> block into my gnuradio/GRC installation on Ubuntu.

Its on the gr\_basic branch on git://gnuradio.org/jblum.git

-Josh