1 files changed, 122 insertions, 0 deletions
diff --git a/lib/edi/STIDecoder.hpp b/lib/edi/STIDecoder.hpp
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+++ b/lib/edi/STIDecoder.hpp
@@ -0,0 +1,122 @@
+/*
+   Copyright (C) 2019
+   Matthias P. Braendli, matthias.braendli@mpb.li
+
+   http://opendigitalradio.org
+
+    This program 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 of the License, or
+    (at your option) any later version.
+
+    This program 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 this program; if not, write to the Free Software Foundation, Inc.,
+    51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+#pragma once
+
+#include "common.hpp"
+#include <cstdint>
+#include <deque>
+#include <string>
+#include <vector>
+
+namespace EdiDecoder {
+
+// Information for STI-D Management
+struct sti_management_data {
+    bool stihf;
+    bool atstf;
+    bool rfadf;
+    uint16_t dflc;
+
+    uint32_t tsta;
+};
+
+// Information for a subchannel available in EDI
+struct sti_payload_data {
+    uint16_t stream_index;
+    uint8_t rfa;
+    uint8_t tid;
+    uint8_t tidext;
+    bool crcstf;
+    uint16_t stid;
+    std::vector<uint8_t> istd;
+
+    // Return the length of ISTD in bytes
+    uint16_t stl(void) const { return istd.size(); }
+};
+
+/* A class that receives STI data must implement the interface described
+ * in the STIDataCollector. This can be e.g. a converter to ETI, or something that
+ * prepares data structures for a modulator.
+ */
+class STIDataCollector {
+    public:
+        // Tell the ETIWriter what EDI protocol we receive in *ptr.
+        // This is not part of the ETI data, but is used as check
+        virtual void update_protocol(
+                const std::string& proto,
+                uint16_t major,
+                uint16_t minor) = 0;
+
+        // STAT error field and service provider ID
+        virtual void update_stat(uint8_t stat, uint16_t spid) = 0;
+
+        // In addition to TSTA in ETI, EDI also transports more time
+        // stamp information.
+        virtual void update_edi_time(uint32_t utco, uint32_t seconds) = 0;
+
+        virtual void update_rfad(std::array<uint8_t, 9> rfad) = 0;
+        virtual void update_sti_management(const sti_management_data& data) = 0;
+
+        virtual void add_payload(sti_payload_data&& payload) = 0;
+
+        virtual void assemble() = 0;
+};
+
+/* The STIDecoder takes care of decoding the EDI TAGs related to the transport
+ * of ETI(NI) data inside AF and PF packets.
+ *
+ * PF packets are handed over to the PFT decoder, which will in turn return
+ * AF packets. AF packets are directly handled (TAG extraction) here.
+ */
+class STIDecoder {
+    public:
+        STIDecoder(STIDataCollector& data_collector, bool verbose);
+
+        /* Push bytes into the decoder. The buf can contain more
+         * than a single packet. This is useful when reading from streams
+         * (files, TCP)
+         */
+        void push_bytes(const std::vector<uint8_t> &buf);
+
+        /* Push a complete packet into the decoder. Useful for UDP and other
+         * datagram-oriented protocols.
+         */
+        void push_packet(const std::vector<uint8_t> &buf);
+
+        /* Set the maximum delay in number of AF Packets before we
+         * abandon decoding a given pseq.
+         */
+        void setMaxDelay(int num_af_packets);
+
+    private:
+        bool decode_starptr(const std::vector<uint8_t> &value, uint16_t);
+        bool decode_dsti(const std::vector<uint8_t> &value, uint16_t);
+        bool decode_ssn(const std::vector<uint8_t> &value, uint16_t n);
+        bool decode_stardmy(const std::vector<uint8_t> &value, uint16_t);
+
+        void packet_completed();
+
+        STIDataCollector& m_data_collector;
+        TagDispatcher m_dispatcher;
+
+};
+
+}