[Discuss-gnuradio] USRP and Variable Bitrate input

[Tom Hendrick]

Hello all.

I am slowly making progress on a streaming application but am coming across some problems with underruns on the transmit side.

I am using a C++ program to modulate an input signal.  Unfortunately the input signal to the C++ has a variable bitrate.  The problem is that the C++ program writes packets once enough data is filled and then sends to a GRC script which runs the USRP.    When the input to the C++ program is somewhat stable, I see no underruns on the USRP, but when the bitrate changes a bit, I see lots of underruns which is causing problems on the receive side because the signal has lots of interruptions.

Does anyone know of any tricks I might be able to try in GRC?  I don't know if there is some way to manipulate a stream like the one I have and make it appear more constant to the USRP.

Unfortunately big changes to the C++ program are difficult for me to do.
Thanks - Tom