From e5fb5f4b7593512a09fd189254f4a433d304898e Mon Sep 17 00:00:00 2001
From: Kamal Mostafa <kamal@whence.com>
Date: Mon, 30 May 2011 18:57:19 -0700
Subject: [PATCH] minimodem: NRZI code (not enabled)

---
 src/minimodem.c | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/src/minimodem.c b/src/minimodem.c
index 5ac2d09..3948eb8 100644
--- a/src/minimodem.c
+++ b/src/minimodem.c
@@ -331,8 +331,17 @@ reprocess_audio:
 
 	if ( carrier_detect )
 	{
+	    unsigned char physical_bit;
 	    carrier_nsymbits++;
-	    bit = signbit(msdelta) ? 0 : 1;
+	    physical_bit = signbit(msdelta) ? 0 : 1;
+
+#undef NRZI
+#ifdef NRZI
+	    bit = lastbit != physical_bit;
+	    lastbit = physical_bit;
+#else
+	    bit = physical_bit;
+#endif
 
 #if 0
 	    static unsigned char lastbit_strong = 0;
@@ -351,7 +360,9 @@ reprocess_audio:
 
 	skipped_frames = 0;
 
+#ifndef NRZI
 	lastbit = bit;
+#endif
 
 	// save 11 bits:
 	//           stop--- v        v--- start bit