GNU Radio File Format for the recorded samples

Question

Do you know the format in which GNU Radio ( File Sink in GNU Radio Companion) stores the samples in the Binary File?

I need to read these samples in Matlab, but the

Answer 1

The file sink is just a dump of the data stream. If the data stream content was simple bytes then the content of the file is straightforward. If the data stream contained complex numbers then the file will contain a list of complex numbers where each complex number is given by two floats and each float by (usually) 4 bytes.

See the files gnuradio/gnuradio-core/src/lib/io/gr_file_sink.cc and gr_file_source.cc for the implementations of the gnuradio file reading and writing blocks.

You could also use python and gnuradio to convert the files into some other format.

from gnuradio import gr
# Assuming the data stream was complex numbers.
src = gr.file_source(gr.sizeof_gr_complex, "the_file_name")
snk = gr.vector_sink_c()
tb = gr.top_block()
tb.connect(src, snk)
tb.run()
# The complex numbers are then accessible as a python list.
data = snk.data()