Function arrayBuffer2SerializedExamples

speech-commands/src/dataset.ts:831–855

(buffer: ArrayBuffer)

/** Decode an ArrayBuffer as intermediate serialization format. */
export function arrayBuffer2SerializedExamples(buffer: ArrayBuffer):
    SerializedExamples {
  tf.util.assert(buffer != null, () => 'Received null or undefined buffer');
  // Check descriptor.
  let offset = 0;
  const descriptor = arrayBuffer2String(
      buffer.slice(offset, DATASET_SERIALIZATION_DESCRIPTOR.length));
  tf.util.assert(
      descriptor === DATASET_SERIALIZATION_DESCRIPTOR,
      () => `Deserialization error: Invalid descriptor`);
  offset += DATASET_SERIALIZATION_DESCRIPTOR.length;
  // Skip the version part for now. It may be used in the future.
  offset += 4;

  // Extract the length of the encoded manifest JSON as a Uint32.
  const manifestLength = new Uint32Array(buffer, offset, 1);
  offset += 4;
  const manifestBeginByte = offset;
  offset = manifestBeginByte + manifestLength[0];
  const manifestBytes = buffer.slice(manifestBeginByte, offset);
  const manifestString = arrayBuffer2String(manifestBytes);
  const manifest = JSON.parse(manifestString);
  const data = buffer.slice(offset);
  return {manifest, data};
}

/**
 * Get valid windows in a long snippet.