On Tue, Feb 26, 2008 at 10:12:44AM -0500, Kshitij Kumar Singh wrote:
> I am having a little problem working with messages. I want to transmit
> an entire binary file using messages over and over again. Eg., msg1
> transmits file x, msg2 again transmits file x
> and so forth. My problem is that I'm unable to find a way to loop over
> the file again and again. I tried using tx_voice.py as a reference but
> was unable to find something suitable.
> Setting repeat to true in gr.file_source won't help either. My goal is
> to send this file using packets(which is why I started out with a
> shorter script using messages) , so repeating or throttling ends up
> making them strings longer than 4096.
> Any help would be much appreciated. Thanks in advance.
>
> Regards,
> Kshitij
I think you are misunderstanding how gr.message_sink works. Since
it's possible to set the item size small (e.g., gr.sizeof_float), it
returns as many samples as it can in a message. It does however
provide you information about what it did in the arg1 and arg2 field.
// build a message to hold whatever we've got
gr_message_sptr msg = gr_make_message(0, // msg type
d_itemsize, // arg1 for other end
noutput_items, // arg2 for other end
(redundant)
noutput_items * d_itemsize); // len
of msg
> -----------------------------------------------------------------------------------------------------------------------------
> from gnuradio import gr
> from struct import unpack
>
> queue = gr.msg_queue(10)
> source = gr.file_source(gr.sizeof_char,'/home/kshitij/work/tp.dat',
> False)
> c2f = gr.char_to_float()
> sink = gr.message_sink(gr.sizeof_float,queue,False)
> tb = gr.top_block()
> tb.connect(source,c2f,sink)
> try:
> tb.start()
> msg = queue.delete_head()
> payload = msg.to_string()
> data = unpack('512f', payload)
> print data, len(payload)
> print msg.type(), msg.arg1(), msg.arg2(), msg.length()
>
> except KeyboardInterrupt:
> pass
> ---------------------------------------------------------------------------------------------------------------------------------
>
Eric
_______________________________________________
Discuss-gnuradio mailing list
Discuss-gnuradio@gnu.org
http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
