Change in 3.7 with buffers

GNU Radio
1

Sorry - I seem to keep running into weird corner cases with my program.
I am having an issue were I am trying to run multiple graphs off the
same source, and decoding different channels digital audio to wav files.
It worked great under 3.6, but with 3.7 they are cutting off
prematurely.

I will keep digging deeper, but I just wanted to check first to see if
this has happened to anyone or if there were any obvious changes to
blocks. If there anything new and special I might have to do to flush
buffers in blocks once I tell it to stop recording and close the file? I
am using wav_file->close();. It is a pretty standard graph using
quad_demo to a gr_DSD block to decode the digital audio and then a
wav_file_sink.

  • Luke
2

On 11/11/2014 05:27 AM, Luke B. wrote:

the file? I am using wav_file->close();. It is a pretty standard
graph using quad_demo to a gr_DSD block to decode the digital audio
and then a wav_file_sink.

This behaviour was not (intentionally) changed. However, calling close()
on a wav file block will not flush any buffers (and never has), it’ll
just write the headers to the WAV file. That it’s cut off doesn’t strike
me as odd, but I’m not sure why it would have worked before. Did you
change buffer sizes?

M

3

I tried to build everything out as a GRC graph. I don’t think it has
anything to do with the wav file sink. I recorded the raw signal and
everything is working fine until it gets to the vocoder block, DSD. It
handles decoding fine when there is only one instance, but when there
are multiple instance of the block running at once, they step on each I
think. So when one block stops it seems to be stopping the wav file for
another.

Each of the blocks store state information for the radio call it is
decoding. Did anything change between 3.6 and 3.7 with the way blocks
are initialized, where some of the class variables are shared between
multiple instances? Is there someway multiple instances of a single
block type might be combined to save on memory?

The DSD block is created and return using the standard make and
gnuradio::get_initial_sptr() pattern.

The weird part is that the same code logic works great in 3.6. I
compared everything in diff and the only meaningful difference is the
header changes for 3.7 classes.

  • Luke