Sorry if this is a duplicate, haven’t found a thread with me specific
config (no UDP).
GNU Radio 188.8.131.52
I have been trying to set up a video link (loop back cable) using named
pipes but am stuck with a crash.
It works until I introduce the USRP into the loop. Though it is the same
set up I use to transmit I text file without trouble.
What I have done:
VLC - Named Pipe - VLC
(fail) - found reference to VLC bugs in forums so gave up on that
VLC - Named Pipe - Mplayer
VLC - Named Pipe 1 - File Source GRC - File Sink GRC - Named Pipe 2 -
VLC - Named Pipe 1 - File Source GRC - OFDM MOD - OFDM DEMOD - File Sink
GRC - Named Pipe 2 - Mplayer
Now with hardware:
VLC - Named Pipe 1 - File Source GRC - OFDM MOD - USRP Sink- USRP
OFDM DEMOD - File Sink GRC - Named Pipe 2 - Mplayer
(FAILS!!). Reports: Segfault (core dumped). GRC file is running, VLC is
streaming. Fail occurs as soon as I open Named Pipe 2 with Mplayer
However, this is the identical GRC - USRP setup I use to repeatedly
transmit a text file successfully.
I have no reason to believe the UHDlib is failing, the segfault I think
a python crash?
The parameters I am using:
cvlc v4l2:///dev/video0 :v4l2-width=160 :v4l2-height=120
sample rate 12.5M
GRC: - not sure of the impact of these settings
These are the ones I am not so sure of:
File source, repeat yes or no?
File Sink, unbuffered on or off? append file on or off?
I am guessing my problem is related to sample rate, buffer sizes, frame
rate etc. I have tried a few permutations without luck though, but not
I have not set camera fps ->
*v4l2-fps *I have hoped the data flow back pressure would be
with by perhaps VLC with default setting (zero)? Or I’d just miss frames
Just looking for some suggestions here I as I have put a good bit of
into this now without luck…