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#!/usr/bin/env python
#
# Copyright 2004,2006 Free Software Foundation, Inc.
#
# This file is part of GNU Radio
#
# GNU Radio is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2, or (at your option)
# any later version.
#
# GNU Radio is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with GNU Radio; see the file COPYING. If not, write to
# the Free Software Foundation, Inc., 51 Franklin Street,
# Boston, MA 02110-1301, USA.
#
from gnuradio import gr, gr_unittest
import atsc # qa code needs to run without being installed
#from gnuradio import atsc
from atsc_utils import *
import sys
class memoize(object):
def __init__(self, thunk):
self.thunk = thunk
self.cached = False
self.value = None
def __call__(self):
if self.cached:
return self.value
self.value = self.thunk()
self.cached = True
return self.value
"""
Make a fake transport stream that's big enough for our purposes.
We generate 8 full fields. This is relatively expensive. It
takes about 2 seconds to execute.
"""
make_transport_stream = \
memoize(lambda : tuple(make_fake_transport_stream_packet(8 * atsc.ATSC_DSEGS_PER_FIELD)))
def pad_transport_stream(src):
"""
An MPEG transport stream packet is 188 bytes long. Internally we use a packet
that is 256 bytes long to help with buffer alignment. This function adds the
appropriate trailing padding to convert each packet from 188 to 256 bytes.
"""
return pad_stream(src, atsc.sizeof_atsc_mpeg_packet, atsc.sizeof_atsc_mpeg_packet_pad)
def depad_transport_stream(src):
"""
An MPEG transport stream packet is 188 bytes long. Internally we use a packet
that is 256 bytes long to help with buffer alignment. This function removes the
trailing padding to convert each packet from 256 back to 188 bytes.
"""
return depad_stream(src, atsc.sizeof_atsc_mpeg_packet, atsc.sizeof_atsc_mpeg_packet_pad)
class vector_source_ts(gr.hier_block):
"""
MPEG Transport stream source for testing.
"""
def __init__(self, fg, ts):
"""
Pad tranport stream packets to 256 bytes and reformat appropriately.
@param fg: flow graph
@param ts: MPEG transport stream.
@type ts: sequence of ints in [0,255]; len(ts) % 188 == 0
"""
src = gr.vector_source_b(pad_transport_stream(ts))
s2v = gr.stream_to_vector(gr.sizeof_char, atsc.sizeof_atsc_mpeg_packet)
fg.connect(src, s2v)
gr.hier_block.__init__(self, fg, None, s2v)
class vector_sink_ts(gr.hier_block):
"""
MPEG Transport stream sink for testing.
"""
def __init__(self, fg):
"""
@param fg: flow graph
"""
v2s = gr.vector_to_stream(gr.sizeof_char, atsc.sizeof_atsc_mpeg_packet)
self.sink = gr.vector_sink_b()
fg.connect(v2s, self.sink)
gr.hier_block.__init__(self, fg, v2s, None)
def data(self):
"""
Extracts tranport stream from sink and returns it to python.
Depads tranport stream packets from 256 back to 188 bytes.
@rtype: tuple of ints in [0,255]; len(result) % 188 == 0
"""
return tuple(depad_transport_stream(self.sink.data()))
class qa_atsc(gr_unittest.TestCase):
def setUp(self):
self.fg = gr.flow_graph()
def tearDown(self):
self.fg = None
# The tests are run in alphabetical order
def test_loopback_000(self):
"""
Loopback randomizer to derandomizer
"""
src_data = make_transport_stream()
expected_result = src_data
src = vector_source_ts(self.fg, src_data)
rand = atsc.randomizer()
derand = atsc.derandomizer()
dst = vector_sink_ts(self.fg)
self.fg.connect(src, rand, derand, dst)
self.fg.run ()
result_data = dst.data ()
self.assertEqual (expected_result, result_data)
def test_loopback_001(self):
"""
Loopback randomizer/rs_encoder to rs_decoder/derandomizer
"""
src_data = make_transport_stream()
expected_result = src_data
src = vector_source_ts(self.fg, src_data)
rand = atsc.randomizer()
rs_enc = atsc.rs_encoder()
rs_dec = atsc.rs_decoder()
derand = atsc.derandomizer()
dst = vector_sink_ts(self.fg)
self.fg.connect(src, rand, rs_enc, rs_dec, derand, dst)
self.fg.run ()
result_data = dst.data ()
self.assertEqual (expected_result, result_data)
def test_loopback_002(self):
"""
Loopback randomizer/rs_encoder/interleaver to
deinterleaver/rs_decoder/derandomizer
"""
src_data = make_transport_stream()
interleaver_delay = 52
expected_result = src_data[0:len(src_data)-(interleaver_delay*atsc.ATSC_MPEG_PKT_LENGTH)]
src = vector_source_ts(self.fg, src_data)
rand = atsc.randomizer()
rs_enc = atsc.rs_encoder()
inter = atsc.interleaver()
deinter = atsc.deinterleaver()
rs_dec = atsc.rs_decoder()
derand = atsc.derandomizer()
dst = vector_sink_ts(self.fg)
self.fg.connect(src, rand, rs_enc, inter, deinter, rs_dec, derand, dst)
self.fg.run ()
result_data = dst.data ()
result_data = result_data[(interleaver_delay*atsc.ATSC_MPEG_PKT_LENGTH):len(result_data)]
self.assertEqual (expected_result, result_data)
def test_loopback_003(self):
"""
Loopback randomizer/rs_encoder/interleaver/trellis_encoder
via ds_to_softds to
viterbi_decoder/deinterleaver/rs_decoder/derandomizer
"""
src_data = make_transport_stream()
interleaver_delay = 52
viterbi_delay = 12
expected_result = src_data[0:len(src_data)-((interleaver_delay+viterbi_delay)*atsc.ATSC_MPEG_PKT_LENGTH)]
src = vector_source_ts(self.fg, src_data)
rand = atsc.randomizer()
rs_enc = atsc.rs_encoder()
inter = atsc.interleaver()
trellis = atsc.trellis_encoder()
softds = atsc.ds_to_softds()
viterbi = atsc.viterbi_decoder()
deinter = atsc.deinterleaver()
rs_dec = atsc.rs_decoder()
derand = atsc.derandomizer()
dst = vector_sink_ts(self.fg)
self.fg.connect(src, rand, rs_enc, inter, trellis, softds, viterbi, deinter, rs_dec, derand, dst)
self.fg.run ()
result_data = dst.data ()[((interleaver_delay+viterbi_delay)*atsc.ATSC_MPEG_PKT_LENGTH):len(dst.data())]
self.assertEqual (expected_result, result_data)
if __name__ == '__main__':
gr_unittest.main()
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