Martin, Thank you for the quick response to my issue!
I cannot release the source code as is, however I can describe what I am doing, and possibly if need be I can release a deprecated version that still exhibits this behavior. I am taking 1 MHz of spectrum and putting this through a 50 channel channelizer to obtain 20 kHz channels. The signals I am interested in are all at +/- 5 kHz of 12 of the original 50 channels; the channels I am not using are fed into NULL sinks. I then take my channels of interest and feed them through a mixer by multiplying the signals by a +/- 4950 Hz complex sinusoid to shift my signals of interest to +/- 50 Hz in each channel. Each channel is then ran through an FIR filter and into an instance of the blocks at question. I have set this up to run with just one channel instead of the 12 as described above and everything works fine, so I believe this may be an issue with having multiple instances of a block alive at the same time. Are the input and output buffers thread safe against multiple instances of the same block running? Michael On Wed, Feb 26, 2014 at 1:42 AM, Martin Braun <martin.br...@ettus.com>wrote: > On 02/26/2014 01:31 AM, Michael Berman wrote: > > I am seeing some odd behavior with an OOT decimation block. What I am > > seeing is chunks of data are being dropped down to noise for random > > calls of the work function in my OOT. To observe this happening, I > > tee'd off the connection going into my OOT module and went strait into a > > file sink and then from within the OOT module for each call of the work > > function I stored off the incoming data to a file; the results of a good > > and bad frame of data are provided in the below links. Within this > > data, the top chart is the file sink tee'd off and you can see it > > tracking well for the most part with the data from within the module on > > the bottom. Within the "bad frame" image however, a little over 1000 > > samples in, the data drops down noise around 0 instead of being a nice > > (and slightly noisy...) sinusoid. The OOT module has a decimation value > > of 4000 in this particular case. I am running on Fedora 20 with a week > > old pull of GNURadio master branch. > > > > Does anybody have any thoughts as to why this is happening, and what I > > could do to resolve it? > > Agreed this is weird. No immediate solution pops to my mind, but can you > provide some more info: > - Is this block part of a larger flow graph, or does this occur also > when you isolate your block? > - Is this code you can share? If so, can we see the OOT > > > The first resolution that is coming to mind would be to re-write my OOT > > module to run with general_work, and manage the input buffer myself. > > Does anybody see any issues with doing this as a work around/solution? > > There's no reason not to do that, but it would be a big surprise if that > helped. After all, a sync_decimator is just a very thin wrapper around a > gr::block. > > > good frame: https://www.dropbox.com/s/tma3qn5byismgha/good_frame.png > > bad frame: https://www.dropbox.com/s/xgvcmlbgma14k0i/bad_frame.jpg > > > > > > Thank you all in advance for the help, > > > > Michael Berman > > > > > > > > _______________________________________________ > > Discuss-gnuradio mailing list > > Discuss-gnuradio@gnu.org > > https://lists.gnu.org/mailman/listinfo/discuss-gnuradio > > > > > _______________________________________________ > Discuss-gnuradio mailing list > Discuss-gnuradio@gnu.org > https://lists.gnu.org/mailman/listinfo/discuss-gnuradio >
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