Re: [Discuss-gnuradio] Different input/output rate

[Holger von Malm]

Thanks a lot Martin.

Ok, now I can regulate the datastream, but one big problem has appeared. 
How do I know when the last item of an inputstream is handled in the 
general_work-function?
This is necessary because I want to add after the last item some bytes 
and the number of incoming items is always unknown.
I made some tests and when I changed the amount of the bytes going into 
my signal-block (coming from a file), I always got different chunks of 
input items in my general_work-function.
The last chunk of input_items handled in "general_work" contains 
sometimes 1 or 4 or 16 or more input_items (so 2^x).
How do I know when the last portion of input_items are handled in 
"general_work"?
Is there a function to check this?

Is it maybe possible to send some outgoing items directly from the 
forecast-function or from the deconstructor?

I hope you or someone else could help me!

Holger

Martin Dvh schrieb:

> Hi Holger,
>
> > The input of my signal block is a bytestream b. The output should
> > also be a bytestream, but with a different number of outgoing 
> > items(not a
> > multiple of b).
> > In other words, after the transformation of the inputstream some 
> > extra-bytes
> > have to be appended. For example:
> >
> > Input y Bytes -------> Output (y Bytes * x) + c ; where y and x are 
> > integers
> > and c Overhead-Bytes: independent from input items
> >
> > The number of input items is not fixed.
> >
> > Is this possible or must the number of output items always be a 
> > multiple of the
> > number of input items?
>
> Yes, this is possible.
> You have to extend from gr_block in stead of gr_sync_block.
> You have to implement your own forecast block and call consume_all 
> yourself.
>
> Look at the gr_simple_framer block. It does just this.
> (src/lib/general/gr_simple_framer.[cc,h,i)]
>
> Greetings,
> Martin