# Using set\_min\_output\_buffer() in Python block **URL:** \ **Category:** GNU Radio\ **Created:** [June 13, 2014, 3:50pm UTC](https://www.ruby-forum.com/t/using-set-min-output-buffer-in-python-block/230367 "2014-06-13T15:50:38Z")\ **Posts on this page:** 7\ **Page:** 1
**Author:** ![jason\_sam](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/j/7993a0/32.png) [@jason\_sam](https://www.ruby-forum.com/u/jason_sam)\ **Post date:** [June 13, 2014, 3:50pm UTC](https://www.ruby-forum.com/t/using-set-min-output-buffer-in-python-block/230367/1 "2014-06-13T15:50:38Z")
Dear All, Is it possible to use set\_min\_output\_buffer() in Python? I want to be able to output more than 4096 items from a Python block during one call to the work function. Is there a way to do this? Regards, David * * * NOTE: The information in this email and any attachments may be confidential and/or legally privileged. This message may be read, copied and used only by the intended recipient. If you are not the intended recipient, please destroy this message, delete any copies held on your system and notify the sender immediately. Toshiba Research Europe Limited, registered in England and Wales (2519556). Registered Office 208 Cambridge Science Park, Milton Road, Cambridge CB4 0GZ, England. Web: www.toshiba.eu/research/trl ---
**Author:** ![divotdave](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/bbe5ce/32.png) [@divotdave](https://www.ruby-forum.com/u/divotdave)\ **Post date:** [June 13, 2014, 8:47pm UTC](https://www.ruby-forum.com/t/using-set-min-output-buffer-in-python-block/230367/2 "2014-06-13T20:47:16Z")
On 13.06.2014 15:49, David Halls wrote: > Dear All, > > Is it possible to use set\_min\_output\_buffer() in Python? I want to be > able to output more than 4096 items from a Python block during one call > to the work function. Is there a way to do this? Hey David, sure, this function is available in Python. It’s even in GRC, if you want to create code to see how it’s used. M ---
**Author:** ![divotdave](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/bbe5ce/32.png) [@divotdave](https://www.ruby-forum.com/u/divotdave)\ **Post date:** [June 16, 2014, 7:03pm UTC](https://www.ruby-forum.com/t/using-set-min-output-buffer-in-python-block/230367/3 "2014-06-16T19:03:56Z")
Hey Martin, My calls using self.set\_min\_output\_buffer(4096\*2) and self.set\_min\_noutput\_items(4096) fail at runtime. Perhaps I am missing some import statements? “AttributeError: ‘bsld\_dec\_butterfly\_cfb’ object has no attribute ‘set\_min\_output\_buffer’” Regards, David * * * From: [discuss-gnuradio-bounces+david.halls=removed\_email\_address@domain.invalid](mailto:discuss-gnuradio-bounces+david.halls=removed_email_address@domain.invalid) [discuss-gnuradio-bounces+david.halls=removed\_email\_address@domain.invalid] on behalf of Martin B. [removed\_email\_address@domain.invalid] Sent: 13 June 2014 19:45 To: [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) Subject: Re: [Discuss-gnuradio] Using set\_min\_output\_buffer() in Python block On 13.06.2014 15:49, David Halls wrote: > Dear All, > > Is it possible to use set\_min\_output\_buffer() in Python? I want to be > able to output more than 4096 items from a Python block during one call > to the work function. Is there a way to do this? Hey David, sure, this function is available in Python. It’s even in GRC, if you want to create code to see how it’s used. M > ## recipient, please destroy this message, delete any copies held on your safely by Mimecast. For more information please visit [http://www.mimecast.com](http://www.mimecast.com) > > * * * > > Discuss-gnuradio mailing list > [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) > [Discuss-gnuradio Info Page](https://lists.gnu.org/mailman/listinfo/discuss-gnuradio) * * * Discuss-gnuradio mailing list [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) > **[Discuss-gnuradio Info Page](https://lists.gnu.org/mailman/listinfo/discuss-gnuradio)** * * * NOTE: The information in this email and any attachments may be confidential and/or legally privileged. This message may be read, copied and used only by the intended recipient. If you are not the intended recipient, please destroy this message, delete any copies held on your system and notify the sender immediately. Toshiba Research Europe Limited, registered in England and Wales (2519556). Registered Office 208 Cambridge Science Park, Milton Road, Cambridge CB4 0GZ, England. Web: www.toshiba.eu/research/trl ---
**Author:** ![divotdave](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/bbe5ce/32.png) [@divotdave](https://www.ruby-forum.com/u/divotdave)\ **Post date:** [June 17, 2014, 9:41am UTC](https://www.ruby-forum.com/t/using-set-min-output-buffer-in-python-block/230367/4 "2014-06-17T09:41:04Z")
On Tue, Jun 17, 2014 at 1:02 AM, David Halls [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > fail at runtime. Perhaps I am missing some import statements? > > “AttributeError: ‘bsld\_dec\_butterfly\_cfb’ object has no attribute > ‘set\_min\_output\_buffer’” > > Regards, > > David The “set\_min\_noutput\_items()” is not yet a supported python statement [1] as per March 06, 2014. Also, I believe this statement should be placed in the member functions (constructor, work function, callback function etc) of your custom block, don’t put it at the wrong place. In alternative, you may want to replace it with “set\_output\_multiple()” if this is more appropriate. 1. [http://gnuradio.4.n7.nabble.com/self-set-min-noutput-items-is-not-a-valid-python-command-in-gnuradio-td46731.html](http://gnuradio.4.n7.nabble.com/self-set-min-noutput-items-is-not-a-valid-python-command-in-gnuradio-td46731.html) ---
**Author:** ![divotdave](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/bbe5ce/32.png) [@divotdave](https://www.ruby-forum.com/u/divotdave)\ **Post date:** [June 17, 2014, 11:44am UTC](https://www.ruby-forum.com/t/using-set-min-output-buffer-in-python-block/230367/5 "2014-06-17T11:44:37Z")
On 16.06.2014 19:02, David Halls wrote: > fail at runtime. Perhaps I am missing some import statements? > > “AttributeError: ‘bsld\_dec\_butterfly\_cfb’ object has no attribute > ‘set\_min\_output\_buffer’” Ah, I misunderstood. You want to use this on Python blocks, I thought you just wanted to call it from Python (on C++ blocks). It it’s not in the gateway blocks, then it won’t work in Python. Cheers, Martin ---
**Author:** ![divotdave](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/bbe5ce/32.png) [@divotdave](https://www.ruby-forum.com/u/divotdave)\ **Post date:** [June 17, 2014, 12:17pm UTC](https://www.ruby-forum.com/t/using-set-min-output-buffer-in-python-block/230367/6 "2014-06-17T12:17:18Z")
* * * > From: Activecat [removed\_email\_address@domain.invalid] > Sent: 17 June 2014 08:39 > To: [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) > Cc: David Halls > Subject: Re: [Discuss-gnuradio] Using set\_min\_output\_buffer() in Python block > On Tue, Jun 17, 2014 at 1:02 AM, David Halls > \<[removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid)[mailto:removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid)\> wrote: > Hey Martin, > My calls using > self.set\_min\_output\_buffer(4096\*2) > and > self.set\_min\_noutput\_items(4096) > fail at runtime. Perhaps I am missing some import statements? > “AttributeError: ‘bsld\_dec\_butterfly\_cfb’ object has no attribute > ‘set\_min\_output\_buffer’” > Regards, > David > The “set\_min\_noutput\_items()” is not yet a supported python statement [1] as per > March 06, 2014. > Also, I believe this statement should be placed in the member functions > (constructor, work function, callback function etc) of your custom block, don’t > put it at the wrong place. > In alternative, you may want to replace it with “set\_output\_multiple()” if this > is more appropriate. > 1. [http://gnuradio.4.n7.nabble.com/self-set-min-noutput-items-is-not-a-valid-python-command-in-gnuradio-td46731.html](http://gnuradio.4.n7.nabble.com/self-set-min-noutput-items-is-not-a-valid-python-command-in-gnuradio-td46731.html) Thanks Activecat!!! I had the problem that “out\_rc[0:len(rcABm)] = rcABm ValueError: operands could not be broadcast together with shapes (4096) (5376)” where “out\_rc = output\_items[3]” using set\_output\_multiple(4096_2) has resolved my problem by increasing the length of the output buffer vector to 4096_2. I wonder if there is a fixed limit as to how far I can stretch this? In the future I may want my decoder to output even more than blocks in one go. Regards, David * * * NOTE: The information in this email and any attachments may be confidential and/or legally privileged. This message may be read, copied and used only by the intended recipient. If you are not the intended recipient, please destroy this message, delete any copies held on your system and notify the sender immediately. Toshiba Research Europe Limited, registered in England and Wales (2519556). Registered Office 208 Cambridge Science Park, Milton Road, Cambridge CB4 0GZ, England. Web: www.toshiba.eu/research/trl ---
**Author:** ![divotdave](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/bbe5ce/32.png) [@divotdave](https://www.ruby-forum.com/u/divotdave)\ **Post date:** [June 18, 2014, 6:55am UTC](https://www.ruby-forum.com/t/using-set-min-output-buffer-in-python-block/230367/7 "2014-06-18T06:55:51Z")
On Tue, Jun 17, 2014 at 6:16 PM, David Halls [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > fixed limit as to how far I can stretch this? In the future I may want my > decoder to output even more than blocks in one go. In GRC graphical flowgraph there is a “Max Number of Output” setting under the “Options” block. Documentation: The Max Number of Output is the maximum number of output items allowed for any block in the flowgraph; to disable this set the max\_nouts equal to 0. Use this to adjust the maximum latency a flowgraph can exhibit. Besides this I guess there is no other limiting factor.