all files / src/webWorker/decodeTask/decoders/ decodeJPEGLS.js

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let charLS;
 
function jpegLSDecode (data, isSigned) {
  // prepare input parameters
  const dataPtr = charLS._malloc(data.length);
 
  charLS.writeArrayToMemory(data, dataPtr);
 
  // prepare output parameters
  const imagePtrPtr = charLS._malloc(4);
  const imageSizePtr = charLS._malloc(4);
  const widthPtr = charLS._malloc(4);
  const heightPtr = charLS._malloc(4);
  const bitsPerSamplePtr = charLS._malloc(4);
  const stridePtr = charLS._malloc(4);
  const allowedLossyErrorPtr = charLS._malloc(4);
  const componentsPtr = charLS._malloc(4);
  const interleaveModePtr = charLS._malloc(4);
 
  // Decode the image
  const result = charLS.ccall(
    'jpegls_decode',
    'number',
    ['number', 'number', 'number', 'number', 'number', 'number', 'number', 'number', 'number', 'number', 'number'],
    [dataPtr, data.length, imagePtrPtr, imageSizePtr, widthPtr, heightPtr, bitsPerSamplePtr, stridePtr, componentsPtr, allowedLossyErrorPtr, interleaveModePtr]
  );
 
  // Extract result values into object
  const image = {
    result,
    width: charLS.getValue(widthPtr, 'i32'),
    height: charLS.getValue(heightPtr, 'i32'),
    bitsPerSample: charLS.getValue(bitsPerSamplePtr, 'i32'),
    stride: charLS.getValue(stridePtr, 'i32'),
    components: charLS.getValue(componentsPtr, 'i32'),
    allowedLossyError: charLS.getValue(allowedLossyErrorPtr, 'i32'),
    interleaveMode: charLS.getValue(interleaveModePtr, 'i32'),
    pixelData: undefined
  };
 
  // Copy image from emscripten heap into appropriate array buffer type
  const imagePtr = charLS.getValue(imagePtrPtr, '*');
 
  if (image.bitsPerSample <= 8) {
    image.pixelData = new Uint8Array(image.width * image.height * image.components);
    image.pixelData.set(new Uint8Array(charLS.HEAP8.buffer, imagePtr, image.pixelData.length));
  } else if (isSigned) {
    image.pixelData = new Int16Array(image.width * image.height * image.components);
    image.pixelData.set(new Int16Array(charLS.HEAP16.buffer, imagePtr, image.pixelData.length));
  } else {
    image.pixelData = new Uint16Array(image.width * image.height * image.components);
    image.pixelData.set(new Uint16Array(charLS.HEAP16.buffer, imagePtr, image.pixelData.length));
  }
 
  // free memory and return image object
  charLS._free(dataPtr);
  charLS._free(imagePtr);
  charLS._free(imagePtrPtr);
  charLS._free(imageSizePtr);
  charLS._free(widthPtr);
  charLS._free(heightPtr);
  charLS._free(bitsPerSamplePtr);
  charLS._free(stridePtr);
  charLS._free(componentsPtr);
  charLS._free(interleaveModePtr);
 
  return image;
}
 
function initializeJPEGLS () {
  // check to make sure codec is loaded
  Iif (typeof CharLS === 'undefined') {
    throw new Error('No JPEG-LS decoder loaded');
  }
 
  // Try to initialize CharLS
  // CharLS https://github.com/cornerstonejs/charls
  Eif (!charLS) {
    charLS = CharLS();
    Iif (!charLS || !charLS._jpegls_decode) {
      throw new Error('JPEG-LS failed to initialize');
    }
  }
 
}
 
function decodeJPEGLS (imageFrame, pixelData) {
  initializeJPEGLS();
 
  const image = jpegLSDecode(pixelData, imageFrame.pixelRepresentation === 1);
 
  // throw error if not success or too much data
  if (image.result !== 0 && image.result !== 6) {
    throw new Error(`JPEG-LS decoder failed to decode frame (error code ${image.result})`);
  }
 
  imageFrame.columns = image.width;
  imageFrame.rows = image.height;
  imageFrame.pixelData = image.pixelData;
 
  return imageFrame;
}
 
export default decodeJPEGLS;
export { initializeJPEGLS };