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[[Category:Block Docs]]
[[Category:Block Docs]]
Depuncture a given block of input samples of . The items produced is based on the pattern. Basically, if:
[[Category:Stub Docs]]
This is the template for the [[:Category:Block_Docs|"Page-per-block Docs"]].  This first section should describe what the block does and how to use it, using however many paragraphs necessary.  Note that the title of the wiki page should match the block's name in GRC, i.e. the one defined in the block's .grc file. Look at the [[FFT]] Block for a good example.
k = 0
As this is a basic template, it's also in the [[:Category:Stub_Docs|"Stub Docs category"]]. Please improve it.
if _puncpat[i] == 1:
    out[i] = input[k++]
    out[i] = symbol # default sym=127
This block is designed for unpacked bits - that is, every input sample is a bit, either a 1 or 0. It's possible to use packed bits as symbols, but the depuncturing will be done on the symbol level, not the bit level.
puncpat is specified as a 32-bit integer that we can convert into the vector _puncpat used in the algorithm above:
_puncpat = [0,...]
for i in puncsize:
    _puncpat[i] = puncpat >> (puncsize-1-i)
puncsize = 8
puncpat = 0xEF  -->  [1,1,1,0,1,1,1,1]
input = [a, b, c, d, e, f, g, h]
output = [a, b, c, 127, e, f, g, h]
The gr.fec Python module provides a read_bitlist function that can turn a string of a puncture pattern into the correct integer form. The pattern of 0xEF could be specified as fec.readbitlist("11101111"). Also, this allows us to use puncsize=len("11101111") to make sure that our sizes are set up correctly for the pattern we want.
The fec.extended_decoder takes in the puncture pattern directly as a string and uses the readbitlist inside to do the conversion.
The  parameter delays the application of the puncture pattern. This is equivalent to circularly rotating the  by . Note that because of the circular shift, the delay should be between 0 and , but this is not enforced; the effective delay will simply be  mod . A negative value here is ignored.
== Parameters ==
== Parameters ==
; Puncture Size
(''R''): <span class="plainlinks">[https://wiki.gnuradio.org/index.php/GNURadioCompanion#Variable_Controls ''Run-time adjustable'']</span>
: Size of block of bits to puncture
; Puncture Pattern
: The puncturing pattern
; Delay
; Param 1 (''R'')
: Delayed the puncturing pattern by shifting it
: Description of parameter, provide any tips or recommended values.  Note that the name of the parameter above should match the param's label that shows up in grc (e.g. Sample Rate).
; Symbol
; Param 2
: The symbol to reinsert into the stream (def=127)
: blah blah blah
== Example Flowgraph ==
== Example Flowgraph ==

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