DataBar: fix inconsistency / plain spec violation (missing "(01)" prefix)

axxel · axxel · commit 36495ef0358c · 2025-04-03T01:11:46.000+02:00
The GS1 DataBar ISO specification clearly states in Section 9 that our two
BarcodeFormats DataBar and DataBarLimited always implicitly encode the AI
"01" prefix. This has been implemented in the new DataBarLimited version
but not in the old DataBar variant.

Also to make the HRI of all DataBar variants (including the Expanded
variant) consistent, all of them are now reported to contain GS1 data and
hence be rendered as "(01)0123...." instead of "010123....".
diff --git a/core/src/oned/ODDataBarLimitedReader.cpp b/core/src/oned/ODDataBarLimitedReader.cpp
@@ -154,7 +154,7 @@ Barcode DataBarLimitedReader::decodePattern(int rowNumber, PatternView& next, st
 			continue;
 
 		return {ConstructText(left, right),    rowNumber, next.pixelsInFront(), next.pixelsTillEnd(),
-				BarcodeFormat::DataBarLimited, {'e', '0'}};
+				BarcodeFormat::DataBarLimited, {'e', '0', 0, AIFlag::GS1}};
 	}
 
 	// guarantee progress (see loop in ODReader.cpp)
diff --git a/core/src/oned/ODDataBarReader.cpp b/core/src/oned/ODDataBarReader.cpp
@@ -140,7 +140,8 @@ static bool ChecksumIsValid(Pair leftPair, Pair rightPair)
 static std::string ConstructText(Pair leftPair, Pair rightPair)
 {
 	auto txt = ToString(Value(leftPair, rightPair), 13);
-	return txt + GTIN::ComputeCheckDigit(txt);
+	// see ISO/IEC 24724:2011 Section 9
+	return "01" + txt + GTIN::ComputeCheckDigit(txt);
 }
 
 struct State : public RowReader::DecodingState
@@ -193,7 +194,7 @@ Barcode DataBarReader::decodePattern(int rowNumber, PatternView& next, std::uniq
 		for (const auto& rightPair : prevState->rightPairs)
 			if (ChecksumIsValid(leftPair, rightPair)) {
 				// Symbology identifier ISO/IEC 24724:2011 Section 9 and GS1 General Specifications 5.1.3 Figure 5.1.3-2
-				Barcode res{DecoderResult(Content(ByteArray(ConstructText(leftPair, rightPair)), {'e', '0'}))
+				Barcode res{DecoderResult(Content(ByteArray(ConstructText(leftPair, rightPair)), {'e', '0', 0, AIFlag::GS1}))
 								.setLineCount(EstimateLineCount(leftPair, rightPair)),
 							{{}, EstimatePosition(leftPair, rightPair)},
 							BarcodeFormat::DataBar};
diff --git a/test/samples/rss14-1/1.txt b/test/samples/rss14-1/1.txt
@@ -1 +1 @@
-04412345678909
+0104412345678909
diff --git a/test/samples/rss14-1/2.txt b/test/samples/rss14-1/2.txt
@@ -1 +1 @@
-00821935106427
+0100821935106427
diff --git a/test/samples/rss14-1/3.txt b/test/samples/rss14-1/3.txt
@@ -1 +1 @@
-00075678164125
+0100075678164125
diff --git a/test/samples/rss14-1/4.txt b/test/samples/rss14-1/4.txt
@@ -1 +1 @@
-20012345678909
+0120012345678909
diff --git a/test/samples/rss14-1/5.txt b/test/samples/rss14-1/5.txt
@@ -1 +1 @@
-00034567890125
+0100034567890125
diff --git a/test/samples/rss14-1/6.txt b/test/samples/rss14-1/6.txt
@@ -1 +1 @@
-00012345678905
+0100012345678905
diff --git a/test/samples/rss14-2/0120358468019312.txt b/test/samples/rss14-2/0120358468019312.txt
@@ -1 +1 @@
-20358468019312
+0120358468019312
diff --git a/test/samples/rss14-2/11.txt b/test/samples/rss14-2/11.txt
@@ -1 +1 @@
-02001234567893
+0102001234567893
diff --git a/test/samples/rss14-2/13.txt b/test/samples/rss14-2/13.txt
@@ -1 +1 @@
-02001234567893
+0102001234567893
diff --git a/test/samples/rss14-2/14.txt b/test/samples/rss14-2/14.txt
@@ -1 +1 @@
-02001234567893
+0102001234567893
diff --git a/test/samples/rss14-2/15.txt b/test/samples/rss14-2/15.txt
@@ -1 +1 @@
-02001234567893
+0102001234567893
diff --git a/test/samples/rss14-2/20.txt b/test/samples/rss14-2/20.txt
@@ -1 +1 @@
-00012345678905
+0100012345678905
diff --git a/test/samples/rss14-2/21.txt b/test/samples/rss14-2/21.txt
@@ -1 +1 @@
-00012345678905
+0100012345678905
diff --git a/test/samples/rss14-2/22.txt b/test/samples/rss14-2/22.txt
@@ -1 +1 @@
-00012345678905
+0100012345678905
diff --git a/test/samples/rss14-2/23.txt b/test/samples/rss14-2/23.txt
@@ -1 +1 @@
-00012345678905
+0100012345678905
diff --git a/test/samples/rss14-2/24.txt b/test/samples/rss14-2/24.txt
@@ -1 +1 @@
-00012345678905
+0100012345678905
diff --git a/test/samples/rss14-2/6.txt b/test/samples/rss14-2/6.txt
@@ -1 +1 @@
-02001234567893
+0102001234567893
diff --git a/test/samples/rss14-2/7.txt b/test/samples/rss14-2/7.txt
@@ -1 +1 @@
-02001234567893
+0102001234567893
diff --git a/test/samples/rss14-2/8.txt b/test/samples/rss14-2/8.txt
@@ -1 +1 @@
-02001234567893
+0102001234567893
diff --git a/test/samples/rss14-2/9.txt b/test/samples/rss14-2/9.txt
@@ -1 +1 @@
-02001234567893
+0102001234567893
diff --git a/test/unit/oned/ODDataBarReaderTest.cpp b/test/unit/oned/ODDataBarReaderTest.cpp
@@ -33,6 +33,6 @@ TEST(ODDataBarReaderTest, Composite)
 		PatternRow row = { 2, 3, 1, 2, 1, 2, 4, 1, 3, 3, 7, 1, 1, 3, 1, 2, 1, 1, 1, 4, 2, 4, 1, 1, 2, 3, 1, 1, 2, 1, 1, 2, 8, 3, 3, 2, 2, 1, 4, 1, 1, 2 };
 		auto result = parse(row);
 		EXPECT_TRUE(result.isValid());
-		EXPECT_EQ(result.text(), "01234567890128");
+		EXPECT_EQ(result.text(), "(01)01234567890128");
 	}
 }

Original file line number	Diff line number	Diff line change
`@@ -154,7 +154,7 @@ Barcode DataBarLimitedReader::decodePattern(int rowNumber, PatternView& next, st`
`154`	`154`	`continue;`
`155`	`155`
`156`	`156`	`return {ConstructText(left, right), rowNumber, next.pixelsInFront(), next.pixelsTillEnd(),`
`157`		`- BarcodeFormat::DataBarLimited, {'e', '0'}};`
	`157`	`+ BarcodeFormat::DataBarLimited, {'e', '0', 0, AIFlag::GS1}};`
`158`	`158`	`}`
`159`	`159`
`160`	`160`	`// guarantee progress (see loop in ODReader.cpp)`