1 files changed, 96 insertions, 0 deletions
diff --git a/contrib/edi/AFPacket.cpp b/contrib/edi/AFPacket.cpp
new file mode 100644
index 0000000..a58a980
--- /dev/null
+++ b/contrib/edi/AFPacket.cpp
@@ -0,0 +1,96 @@
+/*
+   Copyright (C) 2014
+   Matthias P. Braendli, matthias.braendli@mpb.li
+
+    http://www.opendigitalradio.org
+
+   EDI output.
+    This implements an AF Packet as defined ETSI TS 102 821.
+    Also see ETSI TS 102 693
+
+   */
+/*
+   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 "config.h"
+#include "crc.h"
+#include "AFPacket.h"
+#include "TagItems.h"
+#include "TagPacket.h"
+#include <vector>
+#include <string>
+#include <iostream>
+#include <cstdio>
+#include <stdint.h>
+#include <arpa/inet.h>
+
+namespace edi {
+
+// Header PT field. AF packet contains TAG payload
+const uint8_t AFHEADER_PT_TAG = 'T';
+
+// AF Packet Major (3 bits) and Minor (4 bits) version
+const uint8_t AFHEADER_VERSION = 0x10; // MAJ=1, MIN=0
+
+AFPacket AFPacketiser::Assemble(TagPacket tag_packet)
+{
+    std::vector<uint8_t> payload = tag_packet.Assemble();
+
+    if (m_verbose)
+        std::cerr << "Assemble AFPacket " << seq << std::endl;
+
+    std::string pack_data("AF"); // SYNC
+    std::vector<uint8_t> packet(pack_data.begin(), pack_data.end());
+
+    uint32_t taglength = payload.size();
+
+    if (m_verbose)
+        std::cerr << "         AFPacket payload size " << payload.size() << std::endl;
+
+    // write length into packet
+    packet.push_back((taglength >> 24) & 0xFF);
+    packet.push_back((taglength >> 16) & 0xFF);
+    packet.push_back((taglength >> 8) & 0xFF);
+    packet.push_back(taglength & 0xFF);
+
+    // fill rest of header
+    packet.push_back(seq >> 8);
+    packet.push_back(seq & 0xFF);
+    seq++;
+    packet.push_back((have_crc ? 0x80 : 0) | AFHEADER_VERSION); // ar_cf: CRC=1
+    packet.push_back(AFHEADER_PT_TAG);
+
+    // insert payload, must have a length multiple of 8 bytes
+    packet.insert(packet.end(), payload.begin(), payload.end());
+
+    // calculate CRC over AF Header and payload
+    uint16_t crc = 0xffff;
+    crc = crc16(crc, &(packet.front()), packet.size());
+    crc ^= 0xffff;
+
+    if (m_verbose)
+        fprintf(stderr, "         AFPacket crc %x\n", crc);
+
+    packet.push_back((crc >> 8) & 0xFF);
+    packet.push_back(crc & 0xFF);
+
+    if (m_verbose)
+        std::cerr << "         AFPacket length " << packet.size() << std::endl;
+
+    return packet;
+}
+
+}