summaryrefslogtreecommitdiffstats
diff options
context:
space:
mode:
Diffstat
-rw-r--r--doc/advanced.mux7
-rw-r--r--src/ConfigParser.h7
-rw-r--r--src/DabMultiplexer.cpp13
-rw-r--r--src/DabMultiplexer.h9
-rw-r--r--src/DabMux.cpp21
-rw-r--r--src/Makefile.am1
-rw-r--r--src/dabOutput/dabOutput.h4
-rw-r--r--src/dabOutput/edi/Interleaver.cpp114
-rw-r--r--src/dabOutput/edi/Interleaver.h66
9 files changed, 226 insertions, 16 deletions
diff --git a/doc/advanced.mux b/doc/advanced.mux
index 41a3446..10f0b3f 100644
--- a/doc/advanced.mux
+++ b/doc/advanced.mux
@@ -399,6 +399,13 @@ outputs {
; Transportation".
fec 2
+ ; Interleave fragments from several ETI frames so as to reduce the
+ ; probability of errors when several UDP packets are lost in bursts.
+ ; This comes at the cost of larger overall latency between multiplexing
+ ; and modulation. This latency is given in milliseconds, and rounded
+ ; to nearest multiple of 24ms. Set to 0 to disable the interleaver.
+ interleave 0
+
; Length of a RS chunk, can be overriden
;default=207
;chunk_len 207
diff --git a/src/ConfigParser.h b/src/ConfigParser.h
index 6399cdd..ea48e94 100644
--- a/src/ConfigParser.h
+++ b/src/ConfigParser.h
@@ -3,7 +3,7 @@
2011, 2012 Her Majesty the Queen in Right of Canada (Communications
Research Center Canada)
- Copyright (C) 2014
+ Copyright (C) 2016
Matthias P. Braendli, matthias.braendli@mpb.li
The Configuration parser sets up the ensemble according
@@ -28,8 +28,7 @@
You should have received a copy of the GNU General Public License
along with ODR-DabMux. If not, see <http://www.gnu.org/licenses/>.
*/
-#ifndef __CONFIG_PARSER_H_
-#define __CONFIG_PARSER_H_
+#pragma once
#include <vector>
#include <string>
@@ -41,5 +40,3 @@
void parse_ptree(boost::property_tree::ptree& pt,
std::shared_ptr<dabEnsemble> ensemble);
-#endif
-
diff --git a/src/DabMultiplexer.cpp b/src/DabMultiplexer.cpp
index a0c713b..6d3a51e 100644
--- a/src/DabMultiplexer.cpp
+++ b/src/DabMultiplexer.cpp
@@ -181,6 +181,10 @@ void DabMultiplexer::prepare()
throw e;
}
}
+
+ if (edi_conf.interleaver_enabled()) {
+ edi_interleaver.SetLatency(edi_conf.latency_frames);
+ }
#endif
// Shift ms by 14 to Timestamp level 2, see below in Section TIST
@@ -707,8 +711,13 @@ void DabMultiplexer::mux_frame(std::vector<std::shared_ptr<DabOutput> >& outputs
if (edi_conf.enable_pft) {
// Apply PFT layer to AF Packet (Reed Solomon FEC and Fragmentation)
- vector< edi::PFTFragment > edi_fragments =
- edi_pft.Assemble(edi_afpacket);
+ vector<edi::PFTFragment> edi_fragments = edi_pft.Assemble(edi_afpacket);
+
+ if (edi_conf.interleaver_enabled()) {
+ edi_interleaver.PushFragments(edi_fragments);
+
+ edi_fragments = edi_interleaver.Interleave();
+ }
// Send over ethernet
for (const auto& edi_frag : edi_fragments) {
diff --git a/src/DabMultiplexer.h b/src/DabMultiplexer.h
index e2a94f5..b3e432e 100644
--- a/src/DabMultiplexer.h
+++ b/src/DabMultiplexer.h
@@ -23,8 +23,7 @@
along with ODR-DabMux. If not, see <http://www.gnu.org/licenses/>.
*/
-#ifndef __DAB_MULTIPLEXER_H__
-#define __DAB_MULTIPLEXER_H__
+#pragma once
#ifdef HAVE_CONFIG_H
# include "config.h"
@@ -35,6 +34,7 @@
#include "dabOutput/edi/TagPacket.h"
#include "dabOutput/edi/AFPacket.h"
#include "dabOutput/edi/PFT.h"
+#include "dabOutput/edi/Interleaver.h"
#include "fig/FIGCarousel.h"
#include "crc.h"
#include "utils.h"
@@ -102,6 +102,9 @@ class DabMultiplexer : public RemoteControllable {
// The AF Packet will be protected with reed-solomon and split in fragments
edi::PFT edi_pft;
+
+ // To mitigate for burst packet loss, PFT fragments can be sent out-of-order
+ edi::Interleaver edi_interleaver;
#endif // HAVE_OUTPUT_EDI
/* New FIG Carousel */
@@ -130,5 +133,3 @@ class DabMultiplexer : public RemoteControllable {
#define DEFAULT_SERVICE_ID 50
#define DEFAULT_PACKET_ADDRESS 0
-#endif
-
diff --git a/src/DabMux.cpp b/src/DabMux.cpp
index 04d1980..450179d 100644
--- a/src/DabMux.cpp
+++ b/src/DabMux.cpp
@@ -98,10 +98,6 @@ typedef DWORD32 uint32_t;
#include "input/Zmq.h"
#include "dabOutput/dabOutput.h"
-#include "dabOutput/edi/TagItems.h"
-#include "dabOutput/edi/TagPacket.h"
-#include "dabOutput/edi/AFPacket.h"
-#include "dabOutput/edi/PFT.h"
#include "crc.h"
#include "UdpSocket.h"
#include "InetAddress.h"
@@ -311,6 +307,20 @@ int main(int argc, char *argv[])
edi_conf.fec = pt_edi.get<unsigned int>("fec", 3);
edi_conf.chunk_len = pt_edi.get<unsigned int>("chunk_len", 207);
+ double interleave_ms = pt_edi.get<double>("interleave", 0);
+ if (interleave_ms != 0.0) {
+ if (interleave_ms < 0) {
+ throw runtime_error("EDI output: negative interleave value is invalid.");
+ }
+
+ auto latency_rounded = lround(interleave_ms / 24.0);
+ if (latency_rounded * 24 > 30000) {
+ throw runtime_error("EDI output: interleaving set for more than 30 seconds!");
+ }
+
+ edi_conf.latency_frames = latency_rounded;
+ }
+
edi_conf.tagpacket_alignment = pt_edi.get<unsigned int>("tagpacket_alignment", 8);
mux.set_edi_config(edi_conf);
@@ -417,6 +427,9 @@ int main(int argc, char *argv[])
}
etiLog.level(info) << " source port " << edi_dest.source_port;
}
+ if (edi_conf.interleaver_enabled()) {
+ etiLog.level(info) << " interleave " << edi_conf.latency_frames * 24 << " ms";
+ }
}
#endif
diff --git a/src/Makefile.am b/src/Makefile.am
index de2aa37..0d1c454 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -64,6 +64,7 @@ odr_dabmux_SOURCES =DabMux.cpp DabMux.h \
dabOutput/edi/TagItems.cpp dabOutput/edi/TagItems.h \
dabOutput/edi/TagPacket.cpp dabOutput/edi/TagPacket.h \
dabOutput/edi/PFT.cpp dabOutput/edi/PFT.h \
+ dabOutput/edi/Interleaver.cpp dabOutput/edi/Interleaver.h \
ClockTAI.h ClockTAI.cpp \
ConfigParser.cpp ConfigParser.h \
Eti.h Eti.cpp \
diff --git a/src/dabOutput/dabOutput.h b/src/dabOutput/dabOutput.h
index a023da9..11b78e6 100644
--- a/src/dabOutput/dabOutput.h
+++ b/src/dabOutput/dabOutput.h
@@ -69,8 +69,10 @@ struct edi_configuration_t {
unsigned int tagpacket_alignment;
std::vector<edi_destination_t> destinations;
unsigned int dest_port; // common destination port, because it's encoded in the transport layer
+ unsigned int latency_frames; // if nonzero, enable interleaver with a latency of latency_frames * 24ms
- bool enabled() { return destinations.size() > 0; }
+ bool enabled() const { return destinations.size() > 0; }
+ bool interleaver_enabled() const { return latency_frames > 0; }
};
diff --git a/src/dabOutput/edi/Interleaver.cpp b/src/dabOutput/edi/Interleaver.cpp
new file mode 100644
index 0000000..ab3a5fc
--- /dev/null
+++ b/src/dabOutput/edi/Interleaver.cpp
@@ -0,0 +1,114 @@
+/*
+ Copyright (C) 2016
+ Matthias P. Braendli, matthias.braendli@mpb.li
+
+ http://www.opendigitalradio.org
+
+ EDI output,
+ Interleaving of PFT fragments to increase robustness against
+ burst packet loss.
+
+ This is possible because EDI has to assume that fragments may reach
+ the receiver out of order.
+
+ */
+/*
+ This file is part of ODR-DabMux.
+
+ ODR-DabMux 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 3 of the
+ License, or (at your option) any later version.
+
+ ODR-DabMux 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 ODR-DabMux. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "Interleaver.h"
+
+namespace edi {
+
+void Interleaver::SetLatency(size_t latency_frames)
+{
+ m_latency = latency_frames;
+}
+
+void Interleaver::PushFragments(const std::vector<PFTFragment> &fragments)
+{
+ // Create vectors containing Fcount*latency fragments in total
+ // and store them into the deque
+ if (m_buffer.empty()) {
+ m_buffer.push_back(fragments);
+ }
+ else {
+ auto& last_buffer = m_buffer.back();
+
+ const bool last_buffer_is_complete =
+ (last_buffer.size() >= m_fragment_count * m_latency);
+
+ if (last_buffer_is_complete) {
+ m_buffer.push_back(fragments);
+ }
+ else {
+ std::copy(fragments.begin(), fragments.end(),
+ std::back_inserter(last_buffer));
+ }
+ }
+
+ m_fragment_count = fragments.size();
+}
+
+std::vector<PFTFragment> Interleaver::Interleave()
+{
+ std::vector<PFTFragment> fragments;
+
+ while ( not m_buffer.empty() and
+ (m_buffer.front().size() >= m_fragment_count * m_latency)) {
+
+ auto& first_buffer = m_buffer.front();
+
+ assert(first_buffer.size() == m_fragment_count * m_latency);
+
+ /* Assume we have 5 fragments per AF frame, and latency of 3.
+ * This will give the following strides:
+ * 0 1 2
+ * +-------+-------+---+
+ * | 0 1 | 2 3 | 4 |
+ * | | +---+ |
+ * | 5 6 | 7 | 8 9 |
+ * | +---+ | |
+ * |10 |11 12 |13 14 |
+ * +---+-------+-------+
+ *
+ * ix will be 0, 5, 10, 1, 6 in the first loop
+ */
+
+ for (size_t i = 0; i < m_fragment_count; i++) {
+ const size_t ix = m_interleave_offset + m_fragment_count * m_stride;
+ fragments.push_back(first_buffer.at(ix));
+
+ m_stride += 1;
+ if (m_stride >= m_latency) {
+ m_interleave_offset++;
+ m_stride = 0;
+ }
+ }
+
+ if (m_interleave_offset >= m_fragment_count) {
+ m_interleave_offset = 0;
+ m_stride = 0;
+ m_buffer.pop_front();
+ }
+ }
+
+ return fragments;
+}
+
+}
+
+
diff --git a/src/dabOutput/edi/Interleaver.h b/src/dabOutput/edi/Interleaver.h
new file mode 100644
index 0000000..1a2e26d
--- /dev/null
+++ b/src/dabOutput/edi/Interleaver.h
@@ -0,0 +1,66 @@
+/*
+ Copyright (C) 2016
+ Matthias P. Braendli, matthias.braendli@mpb.li
+
+ http://www.opendigitalradio.org
+
+ EDI output,
+ Interleaving of PFT fragments to increase robustness against
+ burst packet loss.
+
+ This is possible because EDI has to assume that fragments may reach
+ the receiver out of order.
+
+ */
+/*
+ This file is part of ODR-DabMux.
+
+ ODR-DabMux 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 3 of the
+ License, or (at your option) any later version.
+
+ ODR-DabMux 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 ODR-DabMux. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#pragma once
+
+#include "config.h"
+#include <vector>
+#include <deque>
+#include <stdexcept>
+#include <stdint.h>
+#include "Log.h"
+#include "PFT.h"
+
+namespace edi {
+
+class Interleaver {
+ public:
+ /* Configure the interleaver to use latency_frames number of AF
+ * packets for interleaving. Total delay through the interleaver
+ * will be latency_frames * 24ms
+ */
+ void SetLatency(size_t latency_frames);
+
+ /* Push the fragments for an AF Packet into the interleaver */
+ void PushFragments(const std::vector< PFTFragment > &fragments);
+
+ std::vector< PFTFragment > Interleave(void);
+
+ private:
+ size_t m_latency = 0;
+ size_t m_fragment_count = 0;
+ size_t m_interleave_offset = 0;
+ size_t m_stride = 0;
+ std::deque<std::vector<PFTFragment> > m_buffer;
+};
+
+}
+
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-11 05:15:51 +0000