Function DoDecode

czxing/src/main/cpp/zxing/src/datamatrix/DMDecoder.cpp:388–435

}

static DecoderResult DoDecode(const BitMatrix& bits)
{
	// Construct a parser and read version, error-correction level
	const Version* version = VersionForDimensionsOf(bits);
	if (version == nullptr)
		return FormatError("Invalid matrix dimension");

	// Read codewords
	ByteArray codewords = CodewordsFromBitMatrix(bits, *version);
	if (codewords.empty())
		return FormatError("Invalid number of code words");

	bool fix259 = false; // see https://github.com/zxing-cpp/zxing-cpp/issues/259
retry:
	// Separate into data blocks
	std::vector<DataBlock> dataBlocks = GetDataBlocks(codewords, *version, fix259);
	if (dataBlocks.empty())
		return FormatError("Invalid number of data blocks");

	// Count total number of data bytes
	ByteArray resultBytes(TransformReduce(dataBlocks, 0, [](const auto& db) { return db.numDataCodewords; }));

	// Error-correct and copy data blocks together into a stream of bytes
	const int dataBlocksCount = Size(dataBlocks);
	for (int j = 0; j < dataBlocksCount; j++) {
		auto& [numDataCodewords, codewords] = dataBlocks[j];
		if (!CorrectErrors(codewords, numDataCodewords)) {
			if(version->versionNumber == 24 && !fix259) {
				fix259 = true;
				goto retry;
			}
			return ChecksumError();
		}

		for (int i = 0; i < numDataCodewords; i++) {
			// De-interlace data blocks.
			resultBytes[i * dataBlocksCount + j] = codewords[i];
		}
	}
#ifdef PRINT_DEBUG
	if (fix259)
		printf("-> needed retry with fix259 for 144x144 symbol\n");
#endif

	// Decode the contents of that stream of bytes
	return DecodedBitStreamParser::Decode(std::move(resultBytes), version->isDMRE())
		.setVersionNumber(version->versionNumber);
}

static BitMatrix FlippedL(const BitMatrix& bits)
{