Hi, there is a patch in the mailing list to this problem in the patch mailing list http://lists.gnu.org/archive/html/patch-gnuradio/2011-07/msg00001.html
I have aplied and it works, Edmar 2011/7/29 niaz ahmed <[email protected]> > Hi, > > I am working on an application ( half duplex communication ) where i have > two flow graphs receiver and transmitter. the scenario is that the receiver > should always be running but when the application require to send something > the receiver flow-graph should be stopped at that time. the reason for the > receiver flow-graph to be stopped is obvious that it should not receive the > data it is sending. i am using laptop sound card (not usrp). > > i am trying to stop the receiver and start it once the transmitter queue > becomes empty but i am getting the following error when i restart the graph > > audio_alsa_source[plughw:0,0]: snd_pcm_hw_params failed: File descriptor in > bad state > > > > > > > class receive_graph(gr.top_block): > > def __init__(self): > gr.top_block.__init__(self) > > self.rcvd_pktq = gr.msg_queue() > > # > #some processing blocks here > # > > self.connect(src,//blocks//,sink) > > > class transmit_graph(gr.top_block): > > def __init__(self): > gr.top_block.__init__(self) > audio_rate =8000 > self.src = gr.message_source(gr.sizeof_char, msgq_limit) > > # > #some processing blocks here > # > > speaker = audio.sink(audio_rate, "plughw:0,0"); > self.connect(src,//blocks//,speaker) > > > > > > if __name__ == '__main__': > try: > fg1 = freceive_graph() > fg1.start() > fg= transmit_graph() > fg.start() > > try: > > > > while True: > message = raw_input("Enter a message to transmit (Ctrl-D to > exit): ") > fg1.stop() #here i am stopping the receiver > graph > # > # here i am making pkt from the message > # > fg.src.msgq().insert_tail(pkt) > if fg.src.msgq().empty_p(): > fg1.start() > > > except EOFError: > print "\nExiting." > fg.src.msgq().insert_tail(gr.message(1)) > fg.wait() > > > > > > > > > > # Main python entry > > except KeyboardInterrupt: > pass > > > > > > -- > *Niaz Ahmed* > > > > “We are always more anxious to be distinguished for a talent which we do > not possess, than to be praised for the fifteen which we do possess”* > : Mark Twain <http://thinkexist.com/quotes/mark_twain/>* > > * <http://thinkexist.com/quotes/mark_twain/>* > > > > _______________________________________________ > Discuss-gnuradio mailing list > [email protected] > https://lists.gnu.org/mailman/listinfo/discuss-gnuradio > > -- --------------- Edmar Candeia Gurjão Universidade Federal de Campina Grande. +55 83 2101 1403 http://ecandeia.dee.ufcg.edu.br http://pet.ee.ufcg.edu.br/
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