Re: [Discuss-gnuradio] File Sink Size

[Marcus D. Leech]

On 04/03/2012 08:48 AM, Jonathan Fox wrote:
> Thats is weird because with me, the file sink will not save anything
> above 1024 in real format. Granted, I never tried anything below that.
>
> -Jon
There's nothing in the file sink that cares one little bit about how big 
your files are.  It just uses the stdio library  to
  write raw samples to whatever file you've specified.  But because it 
uses stdio, it also uses, by default, buffering.
  The default stdio buffer size varies from Linux version of Linux 
version.  So, if you're running along, and then suddenly
  interrupt your app unceremoniously, some number of samples will be 
left in the stdio buffer unwritten.

If you use the "unbuffered" option on the file-sink, you can get it to 
flush the stdio buffers on every write.  This is inefficient,
  and I only recommend it for lower sample rates.

But that's just the stdio buffering.  Internal to Gnu Radio, there are 
also buffers that hold your "samples in flight", and that's of
  an unpredictable size.


> On 4/3/12, frankist<address@hidden>  wrote:
> > Hi,
> >
> > I am using gnuradio companion and I noticed that the block "file sink" isn't
> > written if the number of complex samples stored in it is less or equal to
> > 512. For a bigger number of samples the file has data inside but otherwise
> > it is empty.
> >
> > Is it supposed to be this way? Is there any way to create shorter files?
> > --
> > View this message in context:
> > http://old.nabble.com/File-Sink-Size-tp33545017p33545017.html
> > Sent from the GnuRadio mailing list archive at Nabble.com.
> >
> >
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--
Marcus Leech
Principal Investigator
Shirleys Bay Radio Astronomy Consortium
http://www.sbrac.org