[Python] iOS - Failed to upload video file from Swift to FastAPI backend

I took the code for uploading the video file from this question; however, an error occurs.

This is the code to select a video from an album:

var videoURL: URL?

extension ViewController: UIImagePickerControllerDelegate, UINavigationControllerDelegate {
func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [UIImagePickerController.InfoKey : Any]) {

picker.dismiss(animated: true, completion: nil)
if let pickedVideo = info[UIImagePickerController.InfoKey.mediaURL] as? URL {
videoURL = pickedVideo
}


This is the code to upload the video to the server:

func uploadImage(imageURL: URL?) {

let URL = "http://127.0.0.1:8000/uploadfiles"
let header : HTTPHeaders = [
"Content-Type" : "application/json"]

let timestamp = NSDate().timeIntervalSince1970

AF.upload(multipartFormData: { multipartFormData in
multipartFormData.append(imageURL!, withName: "video", fileName: "\(timestamp).mp4", mimeType: "\(timestamp).mp4")

}, to: URL, usingThreshold: UInt64.init(), method: .post, headers: header).response { response in
guard let statusCode = response.response?.statusCode,
statusCode == 200
else { return }


@IBAction func ButtonClicked(_ sender: UIButton) {
do {
uploadImage(imageURL: videoURL!)

} catch {
}
}



This is the FastAPI server code:

from fastapi import FastAPI, File, UploadFile
from typing import List
import os

app = FastAPI()

@app.get("/")
def read_root():
return { "Hello": "World" }

@app.post("/files/")
async def create_files(files: List[bytes] = File(...)):
return {"file_sizes": [len(file) for file in files]}

@app.post("/uploadfiles")
async def create_upload_files(files: List[UploadFile] = File(...)):
print('here')
UPLOAD_DIRECTORY = "./"
for file in files:
contents = await file.read()
with open(os.path.join(UPLOAD_DIRECTORY, file.filename), "wb") as fp:
fp.write(contents)
print(file.filename)
return {"filenames": [file.filename for file in files]}


This is the error:

INFO: 127.0.0.1:65191 - "POST /uploadfiles HTTP/1.1" 422 Unprocessable Entity

Continue reading...