GNURadio Companion File Sink

GNU Radio
1

What does the vector length option mean? It is set to 1 by default.

–
View this message in context:
http://www.nabble.com/GNURadio-Companion-File-Sink-tp17541624p17541624.html
Sent from the GnuRadio mailing list archive at Nabble.com.

2

Essentially, the gr_file_sink has one parameter, the size of the data
stream in bytes. GRC splits this up into two parameters, the data type
(complex, float, int…) and the vector length. The size of the data
stream = number of bytes in the data type times the vector length.

Unless the data stream is an array of complex, float, int, short, or
byte, the vector length should be 1.

-Josh

3

Im just trying to do a data capture with my USRP. I would like the data
in
complex format. What should the length be set to?

Josh B. wrote:

–
View this message in context:
http://www.nabble.com/GNURadio-Companion-File-Sink-tp17541624p17562873.html
Sent from the GnuRadio mailing list archive at Nabble.com.

4

gr.sizeof_gr_complex

  • George
5

Im not down in the code, Im just trying to use the application. What
does
that number translate to?

Also, once I get the data, how is it formated? as 2 float32 values, one
for
the real arm and one for the imaginary part?

View this message in context:
http://www.nabble.com/GNURadio-Companion-File-Sink-tp17541624p17563384.html
Sent from the GnuRadio mailing list archive at Nabble.com.

6

Josh B. wrote:

isaacgerg wrote:

Im not down in the code, Im just trying to use the application. What
does
that number translate to?

Set the type to complex and leave the vector length as 1.

But the number translates to 8, sizeof(std::complex)

  • George
7

I dont understand, in your previous post you said the following:
"Unless the data stream is an array of complex, float, int, short, or
byte, the vector length should be 1. " Yet, you are telling me it
should be
one. Is this correct?

Josh B. wrote:

the real arm and one for the imaginary part?

–
View this message in context:
http://www.nabble.com/GNURadio-Companion-File-Sink-tp17541624p17563875.html
Sent from the GnuRadio mailing list archive at Nabble.com.

8

isaacgerg wrote:

Im not down in the code, Im just trying to use the application. What does
that number translate to?

Set the type to complex and leave the vector length as 1.

Also, once I get the data, how is it formated? as 2 float32 values, one for
the real arm and one for the imaginary part?

yes, each sample will be written as 2 binary 4 byte floats, i believe
that real part is 1st

9

isaacgerg wrote:

I dont understand, in your previous post you said the following:
"Unless the data stream is an array of complex, float, int, short, or
byte, the vector length should be 1. " Yet, you are telling me it should be
one. Is this correct?

I think that the two statements above agree?

Anyway, most data streams are type complex, float, int, short, or byte.
In this case the vector length for the file sink is always 1. Examples:
usrp source, signal source, noise source…

Sometimes, you have blocks that output an ARRAY/VECTOR of complex,
float, int, short, or bytes for each sample. So each sample is an
array/vector of numbers. Examples: gr_add_vcc, gr_fft_vcc… In this
case, the vector length parameter >= 1.

Makes sense? Is the setting of vector length = 1 not working?

-Josh