From 6bc101d180b61bc51c51795a04f6d29fcf9a40df Mon Sep 17 00:00:00 2001
From: Jonathan Naylor <naylorjs@yahoo.com>
Date: Fri, 8 Jul 2016 07:12:24 +0100
Subject: [PATCH] Further addition of basic operations.

---
 DMRTrellis.cpp | 70 ++++++++++++++++++++++++++++++++++++--------------
 DMRTrellis.h   |  1 +
 2 files changed, 52 insertions(+), 19 deletions(-)

diff --git a/DMRTrellis.cpp b/DMRTrellis.cpp
index b8ee592..b618730 100644
--- a/DMRTrellis.cpp
+++ b/DMRTrellis.cpp
@@ -20,10 +20,10 @@
 #include <cassert>
 
 const unsigned int INTERLEAVE_TABLE[] = {
-	0U, 4U,  8U, 12U, 16U, 20U, 24U, 28U, 32U, 36U, 40U, 44U, 48U,
-	1U, 5U,  9U, 13U, 17U, 21U, 25U, 29U, 33U, 37U, 41U, 45U,
-	2U, 6U, 10U, 14U, 18U, 22U, 26U, 30U, 34U, 38U, 42U, 46U,
-	3U, 7U, 11U, 15U, 19U, 23U, 27U, 31U, 35U, 39U, 43U, 47U};
+	 0U, 16U, 32U, 48U, 64U, 80U,  96U, 112U, 128U, 144U, 160U, 176U, 192U,
+	 4U, 20U, 36U, 52U, 68U, 84U, 100U, 116U, 132U, 148U, 164U, 180U,
+	 8U, 24U, 40U, 56U, 72U, 88U, 104U, 120U, 136U, 152U, 168U, 184U,
+	12U, 28U, 44U, 60U, 76U, 92U, 108U, 124U, 140U, 156U, 172U, 188U};
 
 const unsigned char DIBITS_TO_POINT[] = { 11U,  12U,   0U,   7U,  14U,   9U,   5U,   2U,  10U,  13U,   1U,   6U,  15U,   8U,   4U,   3U};
 const unsigned char POINT_TO_DIBITS[] = {0x2U, 0xAU, 0x7U, 0xFU, 0xEU, 0x6U, 0xBU, 0x3U, 0xDU, 0x5U, 0x8U, 0x0U, 0x1U, 0x9U, 0x4U, 0xCU};
@@ -34,10 +34,9 @@ const unsigned char ENCODE_TABLE[] = {
 	1U,  9U, 5U, 13U, 3U, 11U, 7U, 15U,
 	5U, 13U, 3U, 11U, 7U, 15U, 1U,  9U,
 	3U, 11U, 7U, 15U, 1U,  9U, 5U, 13U,
-	7U, 15U, 1U, 9U,  5U, 13U, 3U, 11U,
+	7U, 15U, 1U,  9U, 5U, 13U, 3U, 11U,
 	2U, 10U, 6U, 14U, 0U,  8U, 4U, 12U,
-	6U, 14U, 0U,  8U, 4U, 12U, 2U, 10U
-};
+	6U, 14U, 0U,  8U, 4U, 12U, 2U, 10U};
 
 const unsigned char BIT_MASK_TABLE[] = {0x80U, 0x40U, 0x20U, 0x10U, 0x08U, 0x04U, 0x02U, 0x01U};
 
@@ -61,6 +60,10 @@ void CDMRTrellis::decode(const unsigned char* data, unsigned char* payload)
 
 	// unsigned char points[49U];
 	// deinterleave(data, points);
+
+	// unsigned char tribits[49U];
+
+	// fromtribits(tribits, payload);
 }
 
 void CDMRTrellis::encode(const unsigned char* payload, unsigned char* data)
@@ -88,15 +91,20 @@ void CDMRTrellis::encode(const unsigned char* payload, unsigned char* data)
 void CDMRTrellis::deinterleave(const unsigned char* data, unsigned char* points) const
 {
 	for (unsigned int i = 0U; i < 49U; i++) {
-		unsigned int n = INTERLEAVE_TABLE[i] * 4U;
-		if (n > 108U) n += 48U;
-
+		unsigned int n = INTERLEAVE_TABLE[i] + 0U;
+		if (n >= 98U) n += 68U;
 		bool b1 = READ_BIT(data, n) != 0x00U;
-		n++;
+
+		n = INTERLEAVE_TABLE[i] + 1U;
+		if (n >= 98U) n += 68U;
 		bool b2 = READ_BIT(data, n) != 0x00U;
-		n++;
+
+		n = INTERLEAVE_TABLE[i] + 2U;
+		if (n >= 98U) n += 68U;
 		bool b3 = READ_BIT(data, n) != 0x00U;
-		n++;
+
+		n = INTERLEAVE_TABLE[i] + 3U;
+		if (n >= 98U) n += 68U;
 		bool b4 = READ_BIT(data, n) != 0x00U;
 
 		unsigned int dibits = 0U;
@@ -120,15 +128,20 @@ void CDMRTrellis::interleave(const unsigned char* points, unsigned char* data) c
 		bool b3 = (dibits & 0x02U) == 0x02U;
 		bool b4 = (dibits & 0x01U) == 0x01U;
 
-		unsigned int n = INTERLEAVE_TABLE[i] * 4U;
-		if (n > 108U) n += 48U;
-
+		unsigned int n = INTERLEAVE_TABLE[i] + 0U;
+		if (n >= 98U) n += 68U;
 		WRITE_BIT(data, n, b1);
-		n++;
+
+		n = INTERLEAVE_TABLE[i] + 1U;
+		if (n >= 98U) n += 68U;
 		WRITE_BIT(data, n, b2);
-		n++;
+
+		n = INTERLEAVE_TABLE[i] + 2U;
+		if (n >= 98U) n += 68U;
 		WRITE_BIT(data, n, b3);
-		n++;
+
+		n = INTERLEAVE_TABLE[i] + 3U;
+		if (n >= 98U) n += 68U;
 		WRITE_BIT(data, n, b4);
 	}
 }
@@ -154,3 +167,22 @@ void CDMRTrellis::totribits(const unsigned char* payload, unsigned char* tribits
 
 	tribits[48U] = 0U;
 }
+
+void CDMRTrellis::fromtribits(const unsigned char* tribits, unsigned char* payload) const
+{
+	for (unsigned int i = 0U; i < 48U; i++) {
+		unsigned char tribit = tribits[i];
+
+		bool b1 = (tribit & 0x04U) == 0x04U;
+		bool b2 = (tribit & 0x02U) == 0x02U;
+		bool b3 = (tribit & 0x01U) == 0x01U;
+
+		unsigned int n = 143U - i * 3U;
+
+		WRITE_BIT(payload, n, b1);
+		n--;
+		WRITE_BIT(payload, n, b2);
+		n--;
+		WRITE_BIT(payload, n, b3);
+	}
+}
diff --git a/DMRTrellis.h b/DMRTrellis.h
index c3b852b..3496c24 100644
--- a/DMRTrellis.h
+++ b/DMRTrellis.h
@@ -26,6 +26,7 @@ private:
 	void deinterleave(const unsigned char* in, unsigned char* points) const;
 	void interleave(const unsigned char* points, unsigned char* out) const;
 	void totribits(const unsigned char* payload, unsigned char* tribits) const;
+	void fromtribits(const unsigned char* tribits, unsigned char* payload) const;
 };
 
 #endif