if (!targetFile.exists()){
    targetFile.createNewFile();
  }

When creating a file, we may be in a series of folders. When the folder does not exist, we cannot create a file

 File targetFile = new File(videoFramesPath+File.separator + dir + File.separator + UUID.randomUUID().toString() + ".jpg");

Solution:
judge whether the folder exists before creating the file,

if (!targetFile.getParentFile().exists()){
  targetFile.getParentFile().mkdirs();
}
if (!targetFile.exists()){
    targetFile.createNewFile();
}