Re: [Discuss-gnuradio] A question about function gr::block::set_history()
On 19.05.2014 17:48, Kun Qian wrote: Thank you for your quick answer! I think I get how gnuradio works with history from your slides: 1. When flowgraph starts, the read pointer of input buffer is set history()-1 items back. 2. After calling work()/general_work() function, gnuradio scheduler get the number of consumed items of that input buffer and move the read pointer forward by that number. Then scheduler wait until next time calling work()/general_work() function. Is it right? And I think I find the error. In gr::block::general_work(), the parameter ninput_items equals to the *sum* of *noutput_items of previous block* and *history()-1*, isn't it? I thought ninput_items equals to noutput_items of previous block when I built the block. That's right. Everything in the input buffer is described by ninput_items, and that includes history. M ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
[Discuss-gnuradio] A question about function gr::block::set_history()
Hi, I wrote a block using gnuradio history functionality. The block is inherited from gr::block (built by command gr_modtool add -t general my_block), with history set to a bit large number, 320. I then finished rest parts of the block. I run the flowgraph and output the input buffer of this block when the general_work() function is called. Then I found the history of the block is stored at the end of the input buffer, which is not as what the tutorial said. For example, suppose my block is prepended by a delay block with delay value set to 16, the content of the input buffer of my block at the first time when general_work() is called is 336 complex zeros. Then my block consume all 16 zeros by calling consume_each(16) and return the number of output items. According the description of gnuradio history functionality, the content of the input buffer of my block at the second time when general_work() is called ought to be 320 complex zeros (history) followed by some data items. Yet in fact, what I get at second time is some data items followed by 320 complex zeros! I have no idea why it happens. Could anyone help me please? Thank you! -- View this message in context: http://gnuradio.4.n7.nabble.com/A-question-about-function-gr-block-set-history-tp48313.html Sent from the GnuRadio mailing list archive at Nabble.com. ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] A question about function gr::block::set_history()
Thank you for your quick answer! I think I get how gnuradio works with history from your slides: 1. When flowgraph starts, the read pointer of input buffer is set history()-1 items back. 2. After calling work()/general_work() function, gnuradio scheduler get the number of consumed items of that input buffer and move the read pointer forward by that number. Then scheduler wait until next time calling work()/general_work() function. Is it right? And I think I find the error. In gr::block::general_work(), the parameter ninput_items equals to the *sum* of *noutput_items of previous block* and *history()-1*, isn't it? I thought ninput_items equals to noutput_items of previous block when I built the block. -- View this message in context: http://gnuradio.4.n7.nabble.com/A-question-about-function-gr-block-set-history-tp48313p48333.html Sent from the GnuRadio mailing list archive at Nabble.com. ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
