Re: [Discuss-gnuradio] Buffer: Change the oldest with the newest

[Andrej Rode]

Hi, 

> I have a GRC in which I am turning USRP stream to vectors of 1024 length.
> Then I have a DSP block (Block 1) that uses these blocks and gives an
> output of length 1024.
> 
> * Then, I want to accumulate 10 of these 1024 length blocks.
> * After 10 of these blocks accumulated, I will give these 10*1024 length
> block to another DSP block(Block 2).
> 
> After I used this 10*1024 block, I don't want this block to be completely
> erased, but I want that it should be updated with the new 1*1024 block
> coming from Block 1. Then I will use this updated 10*1024 block in Block 2.

This functionality is available as `history` function inside of a block.
If you write your own blocks you can call `set_history(9)` and then
will have 9+1 blocks in your input buffer. After you consumed this block
in the next call you again get 9+1 with the "newest" block in the
history being your previous block. Basically you will have a shift
register saving 9 previous blocks and giving them to you.

10x1024 might be more than the default buffer size will allow you, so
you also should increase that.

Cheers
Andrej

-- 
Andrej Rode
GPG Key: 750B CBBB 4A75 811A 4D5F 03ED 5C23 7FB8 9A7D A2AA

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