Configure UHD source and File sink to save integers

GNU Radio
1

I’d like to feed a File Sink from a UHD Source with 4 channels – 2
motherboards, each with A:A A:B subdev specs. To cut down on the file
size, I’d like to record integers instead of floating point.

Which data type should I tell the UHD source to produce? Which type
should I tell the File Sink to record? What conversions do I need in
between? I’d like to stay in GRC, if possible.

TIA

-Marc

2

On 03/04/2013 02:36 PM, mepard wrote:

I’d like to feed a File Sink from a UHD Source with 4 channels – 2
motherboards, each with A:A A:B subdev specs. To cut down on the file
size, I’d like to record integers instead of floating point.

Which data type should I tell the UHD source to produce? Which type
should I tell the File Sink to record? What conversions do I need in
between? I’d like to stay in GRC, if possible.

Sure thing. You can set the file sink to integer (int32), and either set
the usrp source block to vita word32 or sc16 type (both are 32 bits per
sample).

Thats still 4 streams, not sure if you are interleaving them or using 4
file sinks.

-josh

3

On Mar 4, 2013, at 2:43 PM, Josh B. [email protected] wrote:

Sure thing. You can set the file sink to integer (int32), and either set
the usrp source block to vita word32 or sc16 type (both are 32 bits per
sample).

Thats still 4 streams, not sure if you are interleaving them or using 4
file sinks.

One thing I forgot is that I’d like to convert complex to a
single sint16 with just the “real” part, like I can convert
complex to single float. It doesn’t look like there is the
equivalent of Complex To Real for integers.

Is there an alternative to converting to floating point and back?

-Marc

4

On 03/04/2013 03:07 PM, mepard wrote:

between? I’d like to stay in GRC, if possible.
One thing I forgot is that I’d like to convert complex to a single
sint16 with just the “real” part, like I can convert complex to single
float. It doesn’t look like there is the equivalent of Complex To Real for
integers.

Is there an alternative to converting to floating point and back?

you could vector to streams, and null sink the second stream.

  • 1 input stream of vec length 2 and item size short
  • 2 output streams of item size short

-josh

5

On Mar 4, 2013, at 6:11 PM, Josh B. [email protected] wrote:

  • 2 output streams of item size short
    This works well. Thanks!

-Marc