add ryfi decoder module

decoder_modules/ryfi_decoder/src/ryfi/framing.h

@@ -0,0 +1,86 @@
+#pragma once
+#include "dsp/processor.h"
+#include <stdint.h>
+
+namespace ryfi {
+    // Synchronization word.
+    inline const uint64_t SYNC_WORD = 0x341CC540819D8963;
+
+    // Number of synchronization bits.
+    inline const int SYNC_BITS      = 64;
+
+    // Number of synchronization symbols.
+    inline const int SYNC_SYMS      = SYNC_BITS / 2;
+
+    // Possible constellation rotations
+    enum {
+        ROT_0_DEG       = 0,
+        ROT_90_DEG      = 1,
+        ROT_180_DEG     = 2,
+        ROT_270_DEG     = 3
+    };
+
+    /**
+     * RyFi Framer.
+    */
+    class Framer : public dsp::Processor<uint8_t, dsp::complex_t> {
+        using base_type = dsp::Processor<uint8_t, dsp::complex_t>;
+    public:
+        /**
+         * Create a framer specifying an input stream.
+         * @param in Input stream.
+        */
+        Framer(dsp::stream<uint8_t>* in = NULL);
+
+        /**
+         * Encode a frame to symbols adding a sync word.
+        */
+        int encode(const uint8_t* in, dsp::complex_t* out, int count);
+
+    private:
+        int run();
+
+        dsp::complex_t syncSyms[SYNC_SYMS];
+    };
+
+    class Deframer : public dsp::Processor<dsp::complex_t, dsp::complex_t> {
+        using base_type = dsp::Processor<dsp::complex_t, dsp::complex_t>;
+    public:
+        /**
+         * Create a deframer specifying an input stream.
+         * @param in Input stream.
+        */
+        Deframer(dsp::stream<dsp::complex_t> *in = NULL);
+
+    private:
+        int run();
+
+        inline static constexpr int distance(uint64_t a, uint64_t b) {
+            int dist = 0;
+            for (int i = 0; i < 64; i++) {
+                dist += ((a & 1) != (b & 1));
+                a >>= 1;
+                b >>= 1;
+            }
+            return dist;
+        }
+
+        // Frame reading counters
+        int recv = 0;
+        int outCount = 0;
+
+        // Rotation handling
+        int knownRot = 0;
+        uint64_t syncRots[4];
+        dsp::complex_t symRot;
+        const dsp::complex_t symRots[4] = {
+            {  1.0f,  0.0f }, //   0 deg
+            {  0.0f, -1.0f }, //  90 deg
+            { -1.0f,  0.0f }, // 180 deg
+            {  0.0f,  1.0f }, // 270 deg
+        };
+
+        // Shift register
+        uint64_t shift;
+    };
+}