Code cleanups and refactoring.

axfor · Aug 15, 2013 · 76b4461 · 76b4461
1 parent e6d9bf2
commit 76b4461
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Showing 5 changed files with 24 additions and 19 deletions.
diff --git a/ChangeLog b/ChangeLog
@@ -1,3 +1,7 @@
+2013.08.15 Kentaro FUKUCHI <kentaro@fukuchi.org>
+	* rsecc.[ch], qrencode.c, tests/test_rc.c:
+	  - Code cleanups and refactoring.
+
 2013.08.15 Kentaro FUKUCHI <kentaro@fukuchi.org>
 	* rsecc.[ch], rscode.[ch], Makefile.am, qrencode.c:
 	  - Reed-Solomon error correction code has been completely rewritten.

diff --git a/qrencode.c b/qrencode.c
@@ -66,7 +66,7 @@ static void RSblock_initBlock(RSblock *block, int dl, unsigned char *data, int e
 	block->eccLength = el;
 	block->ecc = ecc;
 
-	RSECC_encode(el, 255 - dl - el, data, ecc);
+	RSECC_encode(dl, el, data, ecc);
 }
 
 static int RSblock_init(RSblock *blocks, int spec[5], unsigned char *data, unsigned char *ecc)

diff --git a/rsecc.c b/rsecc.c
@@ -31,12 +31,13 @@
 static int initialized = 0;
 
 #define SYMBOL_SIZE (8)
-static const int proot = 0x11d; /* stands for x^8+x^4+x^3+x^2+1 (see pp.37 of JIS X0510:2004) */
 #define symbols ((1 << SYMBOL_SIZE) - 1)
-#define max_generatorSize (30)
+static const int proot = 0x11d; /* stands for x^8+x^4+x^3+x^2+1 (see pp.37 of JIS X0510:2004) */
 
+/* min/max codeword length of ECC, calculated from the specification. */
 #define min_length (2)
-#define max_length (max_generatorSize)
+#define max_length (30)
+#define max_generatorSize (max_length)
 
 static unsigned char alpha[symbols + 1];
 static unsigned char aindex[symbols + 1];
@@ -96,7 +97,7 @@ static void generator_init(int length)
 	generatorInitialized[length - min_length] = 1;
 }
 
-int RSECC_encode(int length, int pad, const unsigned char *data, unsigned char *ecc)
+int RSECC_encode(int datalength, int ecclength, const unsigned char *data, unsigned char *ecc)
 {
 	int i, j;
 	unsigned char feedback;
@@ -106,24 +107,24 @@ int RSECC_encode(int length, int pad, const unsigned char *data, unsigned char *
 		RSECC_init();
 	}
 
-	if(length > max_length) return -1;
+	if(ecclength > max_length) return -1;
 
-	memset(ecc, 0, length);
-	if(!generatorInitialized[length - min_length]) generator_init(length);
-	gen = generator[length - min_length];
+	memset(ecc, 0, ecclength);
+	if(!generatorInitialized[ecclength - min_length]) generator_init(ecclength);
+	gen = generator[ecclength - min_length];
 
-	for(i = 0; i < symbols - length - pad; i++) {
+	for(i = 0; i < datalength; i++) {
 		feedback = aindex[data[i] ^ ecc[0]];
 		if(feedback != symbols) {
-			for(j = 1; j < length; j++) {
-				ecc[j] ^= alpha[(feedback + gen[length - j]) % symbols];
+			for(j = 1; j < ecclength; j++) {
+				ecc[j] ^= alpha[(feedback + gen[ecclength - j]) % symbols];
 			}
 		}
-		memmove(&ecc[0], &ecc[1], length - 1);
+		memmove(&ecc[0], &ecc[1], ecclength - 1);
 		if(feedback != symbols) {
-			ecc[length - 1] = alpha[(feedback + gen[0]) % symbols];
+			ecc[ecclength - 1] = alpha[(feedback + gen[0]) % symbols];
 		} else {
-			ecc[length - 1] = 0;
+			ecc[ecclength - 1] = 0;
 		}
 	}
 

diff --git a/rsecc.h b/rsecc.h
@@ -23,6 +23,6 @@
 #ifndef __RSECC_H__
 #define __RSECC_H__
 
-extern int RSECC_encode(int length, int pad, const unsigned char *data, unsigned char *ecc);
+extern int RSECC_encode(int datalength, int ecclength, const unsigned char *data, unsigned char *ecc);
 
 #endif /* __RSECC_H__ */
diff --git a/tests/test_rs.c b/tests/test_rs.c
@@ -44,7 +44,7 @@ static void compareRS(unsigned char data[])
 			dl = QRspec_rsDataCodes1(spec);
 			el = QRspec_rsEccCodes1(spec);
 			rs = init_rs(8, 0x11d, 0, 1, el, 255 - dl - el);
-			RSECC_encode(el, 255 - dl - el, data, ecc_rscodec);
+			RSECC_encode(dl, el, data, ecc_rscodec);
 			encode_rs_char(rs, data, ecc_expected);
 			assert_zero(memcmp(ecc_expected, ecc_rscodec, el), "Invalid ECC found: length %d.\n", el);
 			free_rs_char(rs);
@@ -53,7 +53,7 @@ static void compareRS(unsigned char data[])
 			el = QRspec_rsEccCodes2(spec);
 			if(dl != 0) {
 				rs = init_rs(8, 0x11d, 0, 1, el, 255 - dl - el);
-				RSECC_encode(el, 255 - dl - el, data, ecc_rscodec);
+				RSECC_encode(dl, el, data, ecc_rscodec);
 				encode_rs_char(rs, data, ecc_expected);
 				assert_zero(memcmp(ecc_expected, ecc_rscodec, el), "Invalid ECC found: length %d.\n", el);
 				free_rs_char(rs);
@@ -75,7 +75,7 @@ static void compareRSMQR(unsigned char data[])
 			el = MQRspec_getECCLength(i, (QRecLevel)j);
 			if(dl != 0) {
 				rs = init_rs(8, 0x11d, 0, 1, el, 255 - dl - el);
-				RSECC_encode(el, 255 - dl - el, data, ecc_rscodec);
+				RSECC_encode(dl, el, data, ecc_rscodec);
 				encode_rs_char(rs, data, ecc_expected);
 				assert_zero(memcmp(ecc_expected, ecc_rscodec, el), "Invalid ECC found: length %d.\n", el);
 				free_rs_char(rs);