3 # Copyright 2004,2006,2007 Free Software Foundation, Inc.
5 # This file is part of GNU Radio
7 # GNU Radio is free software; you can redistribute it and/or modify
8 # it under the terms of the GNU General Public License as published by
9 # the Free Software Foundation; either version 3, or (at your option)
12 # GNU Radio is distributed in the hope that it will be useful,
13 # but WITHOUT ANY WARRANTY; without even the implied warranty of
14 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 # GNU General Public License for more details.
17 # You should have received a copy of the GNU General Public License
18 # along with GNU Radio; see the file COPYING. If not, write to
19 # the Free Software Foundation, Inc., 51 Franklin Street,
20 # Boston, MA 02110-1301, USA.
23 from gnuradio import gr, gr_unittest
24 import atsc # qa code needs to run without being installed
25 #from gnuradio import atsc
26 from atsc_utils import *
30 class memoize(object):
31 def __init__(self, thunk):
39 self.value = self.thunk()
45 Make a fake transport stream that's big enough for our purposes.
46 We generate 8 full fields. This is relatively expensive. It
47 takes about 2 seconds to execute.
49 make_transport_stream = \
50 memoize(lambda : tuple(make_fake_transport_stream_packet(8 * atsc.ATSC_DSEGS_PER_FIELD)))
53 def pad_transport_stream(src):
55 An MPEG transport stream packet is 188 bytes long. Internally we use a packet
56 that is 256 bytes long to help with buffer alignment. This function adds the
57 appropriate trailing padding to convert each packet from 188 to 256 bytes.
59 return pad_stream(src, atsc.sizeof_atsc_mpeg_packet, atsc.sizeof_atsc_mpeg_packet_pad)
62 def depad_transport_stream(src):
64 An MPEG transport stream packet is 188 bytes long. Internally we use a packet
65 that is 256 bytes long to help with buffer alignment. This function removes the
66 trailing padding to convert each packet from 256 back to 188 bytes.
68 return depad_stream(src, atsc.sizeof_atsc_mpeg_packet, atsc.sizeof_atsc_mpeg_packet_pad)
71 class vector_source_ts(gr.hier_block2):
73 MPEG Transport stream source for testing.
75 def __init__(self, ts):
77 Pad tranport stream packets to 256 bytes and reformat appropriately.
79 @param ts: MPEG transport stream.
80 @type ts: sequence of ints in [0,255]; len(ts) % 188 == 0
83 src = gr.vector_source_b(pad_transport_stream(ts))
84 s2v = gr.stream_to_vector(gr.sizeof_char, atsc.sizeof_atsc_mpeg_packet)
86 gr.hier_block2.__init__(self, "vector_source_ts",
87 gr.io_signature(0, 0, 0),
88 s2v.output_signature())
89 self.connect(src, s2v, self)
92 class vector_sink_ts(gr.hier_block2):
94 MPEG Transport stream sink for testing.
100 v2s = gr.vector_to_stream(gr.sizeof_char, atsc.sizeof_atsc_mpeg_packet)
101 self.sink = gr.vector_sink_b()
102 gr.hier_block2.__init__(self, "vector_sink_ts",
103 v2s.input_signature(),
104 gr.io_signature(0, 0, 0))
105 self.connect(self, v2s, self.sink)
109 Extracts tranport stream from sink and returns it to python.
111 Depads tranport stream packets from 256 back to 188 bytes.
112 @rtype: tuple of ints in [0,255]; len(result) % 188 == 0
114 return tuple(depad_transport_stream(self.sink.data()))
118 class qa_atsc(gr_unittest.TestCase):
121 self.tb = gr.top_block()
127 # The tests are run in alphabetical order
129 def test_loopback_000(self):
131 Loopback randomizer to derandomizer
133 src_data = make_transport_stream()
134 expected_result = src_data
136 src = vector_source_ts(src_data)
137 rand = atsc.randomizer()
138 derand = atsc.derandomizer()
139 dst = vector_sink_ts()
140 self.tb.connect(src, rand, derand, dst)
142 result_data = dst.data ()
143 self.assertEqual (expected_result, result_data)
145 def test_loopback_001(self):
147 Loopback randomizer/rs_encoder to rs_decoder/derandomizer
149 src_data = make_transport_stream()
150 expected_result = src_data
152 src = vector_source_ts(src_data)
153 rand = atsc.randomizer()
154 rs_enc = atsc.rs_encoder()
155 rs_dec = atsc.rs_decoder()
156 derand = atsc.derandomizer()
157 dst = vector_sink_ts()
158 self.tb.connect(src, rand, rs_enc, rs_dec, derand, dst)
160 result_data = dst.data ()
161 self.assertEqual (expected_result, result_data)
163 def test_loopback_002(self):
165 Loopback randomizer/rs_encoder/interleaver to
166 deinterleaver/rs_decoder/derandomizer
168 src_data = make_transport_stream()
169 interleaver_delay = 52
170 expected_result = src_data[0:len(src_data)-(interleaver_delay*atsc.ATSC_MPEG_PKT_LENGTH)]
172 src = vector_source_ts(src_data)
173 rand = atsc.randomizer()
174 rs_enc = atsc.rs_encoder()
175 inter = atsc.interleaver()
176 deinter = atsc.deinterleaver()
177 rs_dec = atsc.rs_decoder()
178 derand = atsc.derandomizer()
179 dst = vector_sink_ts()
180 self.tb.connect(src, rand, rs_enc, inter, deinter, rs_dec, derand, dst)
182 result_data = dst.data ()
183 result_data = result_data[(interleaver_delay*atsc.ATSC_MPEG_PKT_LENGTH):len(result_data)]
184 self.assertEqual (expected_result, result_data)
187 def test_loopback_003(self):
189 Loopback randomizer/rs_encoder/interleaver/trellis_encoder
191 viterbi_decoder/deinterleaver/rs_decoder/derandomizer
193 src_data = make_transport_stream()
194 interleaver_delay = 52
196 expected_result = src_data[0:len(src_data)-((interleaver_delay+viterbi_delay)*atsc.ATSC_MPEG_PKT_LENGTH)]
198 src = vector_source_ts(src_data)
199 rand = atsc.randomizer()
200 rs_enc = atsc.rs_encoder()
201 inter = atsc.interleaver()
202 trellis = atsc.trellis_encoder()
203 softds = atsc.ds_to_softds()
204 viterbi = atsc.viterbi_decoder()
205 deinter = atsc.deinterleaver()
206 rs_dec = atsc.rs_decoder()
207 derand = atsc.derandomizer()
208 dst = vector_sink_ts()
209 self.tb.connect(src, rand, rs_enc, inter, trellis, softds, viterbi, deinter, rs_dec, derand, dst)
211 result_data = dst.data ()[((interleaver_delay+viterbi_delay)*atsc.ATSC_MPEG_PKT_LENGTH):len(dst.data())]
212 self.assertEqual (expected_result, result_data)
215 if __name__ == '__main__':