[Discuss-gnuradio] Value of noutput_items

Hi,
I don't understand the reason why the noutput_items is different in first two lines from the other lines (see below).

Generating: '/home/alice/project_GNURADIO/tx_ofdm.py'

Executing: /usr/bin/python -u /home/alice/project_GNURADIO/tx_ofdm.py

Using Volk machine: avx2_64_mmx_orc
d_i: 1
/* noutput_items */8192
d_i: 2

(tx_ofdm.py:4455): Gtk-WARNING **: gtk_widget_size_allocate(): attempt to allocate widget with width -5 and height 17

(tx_ofdm.py:4455): Gtk-WARNING **: gtk_widget_size_allocate(): attempt to allocate widget with width -5 and height 17

(tx_ofdm.py:4455): Gtk-WARNING **: gtk_widget_size_allocate(): attempt to allocate widget with width -5 and height 17

(tx_ofdm.py:4455): Gtk-WARNING **: gtk_widget_size_allocate(): attempt to allocate widget with width -5 and height 17
/* noutput_items */8191
d_i: 3
/* noutput_items */48
d_i: 4
/* noutput_items */48
d_i: 5
/* noutput_items */48

This is my code when I defines the io_signature:

gr::io_signature::make(0, 0, 0),
gr::io_signature::make(1, 1, sizeof(int)),

I also tried to set Max Output Buffer to 48 (I noticed that warning messages disappeared), but it gives the following warning:

gr::log :WARN: flat_flowgraph - Block (vector_source_tagged0) max output buffer set to 1024 instead of requested 48

and then

d_i: 1
/* noutput_items */512
d_i: 2
/* noutput_items */511
d_i: 3
/* noutput_items */48
d_i: 4
/* noutput_items */48  
....

Why? Any ideas?


Thanks in advance,
Alice