Created
November 18, 2018 00:16
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Read MJPEG int CGImage using Swift4, URLSession, OSX
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// | |
// main.swift | |
// MJPEGreader | |
// | |
// Created by michal on 17/11/2017. | |
// Copyright © 2018 michal. All rights reserved. | |
// | |
import Foundation | |
let configuration = URLSessionConfiguration.ephemeral | |
var urlComponents = URLComponents(string: "http://192.168.0.27:8080")! | |
urlComponents.query = "action=stream" | |
let url = urlComponents.url! | |
enum MjpegReadError: Error { | |
case badResponse, parseImage | |
} | |
class MjpegRead: NSObject, URLSessionDelegate, URLSessionDataDelegate { | |
let startMarker: Data = Data(bytes: [0xFF, 0xD8]) | |
let endMarker: Data = Data(bytes: [0xFF, 0xD9]) | |
var buffer: Data = Data() | |
let configuration = URLSessionConfiguration.ephemeral | |
var session: URLSession? | |
var task: URLSessionDataTask? | |
var handler: ((CGImage?, MjpegReadError?)->())? | |
func readStream(_ url: URL, handler: @escaping (CGImage?, MjpegReadError?)->()) { | |
self.handler = handler | |
session = URLSession.init(configuration: configuration, delegate: self, delegateQueue: nil) | |
task = session?.dataTask(with: url) | |
task?.resume() | |
} | |
func stopStream() { | |
task?.cancel() | |
task = nil | |
} | |
// MARK: Session Delegates | |
func urlSession(_ session: URLSession, dataTask: URLSessionDataTask, didReceive data: Data) { | |
guard let response = dataTask.response as? HTTPURLResponse, response.statusCode == 200 else { | |
handler?(nil, .badResponse) | |
return | |
} | |
if data.range(of: startMarker) != nil { | |
print("started new frame") | |
buffer = Data() // clean up buffer | |
} | |
buffer.append(data) | |
// frame has ended if not nil | |
if data.range(of: endMarker) != nil { | |
print ("finished frame") | |
let frame = parseFrame(buffer) | |
handler?(frame, nil) | |
} | |
} | |
private func parseFrame(_ data: Data) -> CGImage? { | |
guard let imgProvider = CGDataProvider.init(data: data as CFData) else { | |
handler?(nil, .parseImage) | |
return nil | |
} | |
guard let image = CGImage.init(jpegDataProviderSource: imgProvider, decode: nil, shouldInterpolate: true, intent: CGColorRenderingIntent.defaultIntent) else { | |
handler?(nil, .parseImage) | |
return nil | |
} | |
return image | |
} | |
} | |
let mjpegRead = MjpegRead() | |
mjpegRead.readStream(url) { image, error in | |
if let error = error { | |
print(error.localizedDescription) | |
} | |
if let image = image { | |
print("image:", image.width, image.height) | |
} | |
} | |
dispatchMain() |
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Thanks for this, you saved my life. Worked perfectly.