Read Apple Maker Note Asset Identifier from a HEIC file and a MOV file (live photo)

modifyPhotoId.swift

import Foundation
import ImageIO

func modifyAndSaveHEICPhoto(atPath path: String, assetIdentifier: String) {
    let imageSource = CGImageSourceCreateWithURL(URL(fileURLWithPath: path) as CFURL, nil)
    let imageProperties = CGImageSourceCopyPropertiesAtIndex(imageSource!, 0, nil) as? [CFString: Any]
    var modifiedProperties = imageProperties!
    var appleMakerDict = modifiedProperties[kCGImagePropertyMakerAppleDictionary] as? [CFString: Any]
    appleMakerDict?["17" as CFString] = assetIdentifier
    modifiedProperties[kCGImagePropertyMakerAppleDictionary] = appleMakerDict
    let newImageData = NSMutableData()
    let destination = CGImageDestinationCreateWithData(newImageData, CGImageSourceGetType(imageSource!)!, 1, nil)!
    CGImageDestinationAddImageFromSource(destination, imageSource!, 0, modifiedProperties as CFDictionary)
    CGImageDestinationFinalize(destination)

    let newFilePath = (path as NSString).deletingPathExtension + "_modified.HEIC"
    newImageData.write(toFile: newFilePath, atomically: true)
    print("Modified photo saved at: \(newFilePath)")
}

let heicFilePath = CommandLine.arguments[1]
let assetIdentifier = CommandLine.arguments[2] 
modifyAndSaveHEICPhoto(atPath: heicFilePath, assetIdentifier: assetIdentifier)

movieId.swift

import AVFoundation
import Foundation

func fetchAssetIdentifier(fromURL url: URL) async -> String? {
  let asset = AVAsset(url: url)
  let metadata = try! await asset.loadMetadata(for: AVMetadataFormat.quickTimeMetadata)
  for item in metadata {
    let key = item.commonKey?.rawValue
    let value = try! await item.load(.value)

    if key == "identifier" {
      return value as? String
    }
  }
  return nil
}

let movieFilePath = CommandLine.arguments[1]
let movieURL = URL(fileURLWithPath: movieFilePath)
let assetIdentifier = await fetchAssetIdentifier(fromURL: movieURL)
print("Asset Identifier: \(assetIdentifier!)")

photoId.swift

import Foundation
import ImageIO

func fetchAssetIdentifier(fromHEICPhotoAtPath path: String) -> String? {
  let imageSource = CGImageSourceCreateWithURL(URL(fileURLWithPath: path) as CFURL, nil)
  let imageProperties = CGImageSourceCopyPropertiesAtIndex(imageSource!, 0, nil) as? [CFString: Any]

  let appleMakerDict = imageProperties?[kCGImagePropertyMakerAppleDictionary] as? [CFString: Any]

  for (key, value) in appleMakerDict! {
    if key as String == "17" {
      return value as? String
    }
  }
  return nil
}

let heicFilePath = CommandLine.arguments[1]
let assetIdentifier = fetchAssetIdentifier(fromHEICPhotoAtPath: heicFilePath)!
print("Asset Identifier: \(assetIdentifier)")

Usage example:

swift photoId.swift example.HEIC
swift movieId.swift example2.mov
swift modifyPhotoId.swift example.HEIC <another-id>

You can use these three scripts to combine a static photo and a short video into a Apple's Live Photo.

BTW, check out my blog about how Apple Live Photo works :)