Is there a way to slow the playback of a data file through an FFT Sink?
If
I recorded at 50M and I set my FFT rate to 25M, would that result in
playback twice as long?
Thanks.
On Thu, Dec 26, 2013 at 5:31 PM, Paul B. Huter [email protected]
wrote:
Is there a way to slow the playback of a data file through an FFT Sink? If I
recorded at 50M and I set my FFT rate to 25M, would that result in playback
twice as long?Thanks.
No, the sample rate of the FFT sink is just for display purposes: it
sets the range of the x-axis and nothing more.
If you want to slow down your display, assuming there is no hardware
in the loop, you can use a throttle block with a fairly low rate.
Tom
Sounds good, thanks.
Paul B. Huter
I often “speed up” the playback of large recordings by adjusting the
throttle only. In the throttle block, I just multiple the recorded
sample
rate by a factor (say 10) to get increased playback speed. Don’t change
any other blocks’ parameters - just the throttle.
Very Respectfully,
Dan CaJacob
Tom:
What would you recommend if my data was recorded at 50M for about 15
seconds and I would like to double to playback time with a throttle. If
I
set the throttle to 25M, would that do the trick, or is it more
complicated
than that? I’m waiting for a new shipment of RAM, and once I have that I
will be able to play around with things, but I just thought I would
query
the group to get a good starting point.
Thanks.
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Hi Paul,
yes, that would basically make a 1s recording (50e6 Samples) play in 2s.
Be aware however that 25Msam/s is still a lot to process, so the
throttled samples might still stress out your CPU 
Have nice new year,
Marcus
On 26.12.2013 23:31, Paul B. Huter wrote:
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Thanks, Marcus. The limiting factor for the flows I have seems to be RAM
more than anything, and I will be back at 8GB tomorrow, hopefully, and
things should be good.
Thanks, and Happy New Year.
Paul B. Huter