1 files changed, 74 insertions, 0 deletions
diff --git a/contrib/edi/Interleaver.h b/contrib/edi/Interleaver.h
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+++ b/contrib/edi/Interleaver.h
@@ -0,0 +1,74 @@
+/*
+   Copyright (C) 2017
+   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 "edi/PFT.h"
+
+namespace edi {
+
+class Interleaver {
+    public:
+        using fragment_vec = std::vector<PFTFragment>;
+
+        /* 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);
+
+        /* Move the fragments for an AF Packet into the interleaver and
+         * return interleaved fragments to be transmitted.
+         */
+        fragment_vec Interleave(fragment_vec &fragments);
+
+    private:
+        size_t m_latency = 0;
+        size_t m_fragment_count = 0;
+        size_t m_interleave_offset = 0;
+        size_t m_stride = 0;
+
+        /* Buffer that accumulates enough fragments to interleave */
+        std::deque<fragment_vec> m_buffer;
+
+        /* Buffer that contains fragments that have been interleaved,
+         * to avoid that the interleaver output is too bursty
+         */
+        std::deque<PFTFragment> m_interleaved_fragments;
+};
+
+}
+