Function decodeMatrix

src/decoder/decoder.ts:288–325

(matrix: BitMatrix)

}

function decodeMatrix(matrix: BitMatrix) {
  const version = readVersion(matrix);
  if (!version) {
    return null;
  }

  const formatInfo = readFormatInformation(matrix);
  if (!formatInfo) {
    return null;
  }

  const codewords = readCodewords(matrix, version, formatInfo);
  const dataBlocks = getDataBlocks(codewords, version, formatInfo.errorCorrectionLevel);
  if (!dataBlocks) {
    return null;
  }

  // Count total number of data bytes
  const totalBytes = dataBlocks.reduce((a, b) => a + b.numDataCodewords, 0);
  const resultBytes = new Uint8ClampedArray(totalBytes);

  let resultIndex = 0;
  for (const dataBlock of dataBlocks) {
    const correctedBytes = rsDecode(dataBlock.codewords, dataBlock.codewords.length - dataBlock.numDataCodewords);
    if (!correctedBytes) {
      return null;
    }
    for (let i = 0; i < dataBlock.numDataCodewords; i++) {
      resultBytes[resultIndex++] = correctedBytes[i];
    }
  }

  try {
    return decodeData(resultBytes, version.versionNumber);
  } catch {
    return null;
  }
}

export function decode(matrix: BitMatrix): DecodedQR {
  if (matrix == null) {