basic block

from gnuradio import gr
import numpy


class stream_crc(gr.basic_block):
    " Stream CRC"

    def __init__(self, packetLength, lengthTagKey):
        gr.basic_block.__init__(
            self,
            name="stream_crc",
            in_sig=[numpy.byte],
            out_sig=[numpy.byte]
        )
        self.packetLength = packetLength

    def general_work(self, input_items, output_items):
        print 'general_work'
        print input_items

        output_items[0] = input_items[0]
        print '>>', type(output_items[0]), type(input_items[0])
        print 'len(output_items[0]) = '+str(len(output_items[0]))+' len(input_items[0]) = '+str(len(input_items[0]))
        print "output: ", output_items
        print output_items
        print '#######'
        return len(output_items[0])




    def forecast(self, noutput_items, ninput_items_required):
        """
        forecast is only called from a general block
        this is the default implementation
        """
        ninput_items_required[0] = noutput_items
        print "Forecast:\n noutput_items: "
        print noutput_items
        print "ninput_items_required: "
        print ninput_items_required[0]

        return