Re: [Discuss-gnuradio] Using forecast() for input dependant output?

[Martin Braun (CEL)]

On Mon, Jan 07, 2013 at 03:09:35AM -0800, MJS wrote:
> I'm currently working on an arbitrary ratio block, the idea is that the
> output rate of the block is completely dependent on the data received, ie,
> there is no way to know how much data will be output until the input data is
> processed. This doesn't seem to match exactly the definition of the
> arbitrary ratio block. Could anyone suggest an implementation for forecast()
> to accomplish this?

Hi MJS,

we're currently doing something similar on the OFDM-reimplementation.
As an example, check this out:
https://github.com/benreynwar/gnuradio/blob/ofdm/gr-digital/lib/digital_ofdm_carrier_allocator_cvc.cc

The gist:
- set_relative_rate() is simply set to the best approximation
  (if completely random, leave at 1.0)
- use a block member to 'communicate' with forecast()
- set_output_multiple() helps keeping the out buffer large enough

The 'arbitrary ratio' block (aka gr_block) doesn't necessarily need a
'ratio' between in- and output rates.
You can consume and produce as you wish.

M

-- 
Karlsruhe Institute of Technology (KIT)
Communications Engineering Lab (CEL)

Dipl.-Ing. Martin Braun
Research Associate

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KIT -- University of the State of Baden-Württemberg and
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