Simple MJPEG stream decoder for Unity written in C#

[godheisenberg]

using System.IO;
	using System.Threading;
	using System.Collections;
	using System.Collections.Generic;
	using System.Net;
	using UnityEngine;
	public class MJPEGStreamDecoder : MonoBehaviour
	{
	[SerializeField] bool tryOnStart = false;
	[SerializeField] string defaultStreamURL = "http://127.0.0.1/stream";
	[SerializeField] RenderTexture renderTexture;
	float RETRY_DELAY = 5f;
	int MAX_RETRIES = 3;
	int retryCount = 0;
	byte[] nextFrame = null;
	Thread worker;
	int threadID = 0;
	static System.Random randu; // I use my own System.Random instead of the shared UnityEngine.Random to avoid collisions
	List<BufferedStream> trackedBuffers = new List<BufferedStream>();
	// Start is called before the first frame update
	void Start()
	{
	randu = new System.Random(Random.Range(0, 65536));
	if (tryOnStart)
	StartStream(defaultStreamURL);
	}
	private void Update()
	{
	if (nextFrame != null)
	{
	SendFrame(nextFrame);
	nextFrame = null;
	}
	}
	private void OnDestroy()
	{
	foreach (var b in trackedBuffers)
	{
	if (b != null)
	b.Close();
	}
	}
	public void StartStream(string url)
	{
	retryCount = 0;
	StopAllCoroutines();
	foreach (var b in trackedBuffers)
	b.Close();
	worker = new Thread(() => ReadMJPEGStreamWorker(threadID = randu.Next(65536), url));
	worker.Start();
	}
	void ReadMJPEGStreamWorker(int id, string url)
	{
	var webRequest = WebRequest.Create(url);
	webRequest.Method = "GET";
	List<byte> frameBuffer = new List<byte>();
	int lastByte = 0x00;
	bool addToBuffer = false;
	BufferedStream buffer = null;
	try
	{
	Stream stream = webRequest.GetResponse().GetResponseStream();
	buffer = new BufferedStream(stream);
	trackedBuffers.Add(buffer);
	}
	catch (System.Exception ex)
	{
	Debug.LogError(ex);
	}
	int newByte;
	while (buffer != null)
	{
	if (threadID != id) return; // We are no longer the active thread! stop doing things damnit!
	if (!buffer.CanRead)
	{
	Debug.LogError("Can't read buffer!");
	break;
	}
	newByte = -1;
	try
	{
	newByte = buffer.ReadByte();
	}
	catch
	{
	break; // Something happened to the stream, start a new one
	}
	if (newByte < 0) // end of stream or failure
	{
	continue; // End of data
	}
	if (addToBuffer)
	frameBuffer.Add((byte)newByte);
	if (lastByte == 0xFF) // It's a command!
	{
	if (!addToBuffer) // We're not reading a frame, should we be?
	{
	if (IsStartOfImage(newByte))
	{
	addToBuffer = true;
	frameBuffer.Add((byte)lastByte);
	frameBuffer.Add((byte)newByte);
	}
	}
	else // We're reading a frame, should we stop?
	{
	if (newByte == 0xD9)
	{
	frameBuffer.Add((byte)newByte);
	addToBuffer = false;
	nextFrame = frameBuffer.ToArray();
	frameBuffer.Clear();
	}
	}
	}
	lastByte = newByte;
	}
	if (retryCount < MAX_RETRIES)
	{
	retryCount++;
	Debug.LogFormat("[{0}] Retrying Connection {1}...", id, retryCount);
	foreach (var b in trackedBuffers)
	b.Dispose();
	trackedBuffers.Clear();
	worker = new Thread(() => ReadMJPEGStreamWorker(threadID = randu.Next(65536), url));
	worker.Start();
	}
	}
	bool IsStartOfImage(int command)
	{
	switch (command)
	{
	case 0x8D:
	Debug.Log("Command SOI");
	return true;
	case 0xC0:
	Debug.Log("Command SOF0");
	return true;
	case 0xC2:
	Debug.Log("Command SOF2");
	return true;
	case 0xC4:
	Debug.Log("Command DHT");
	break;
	case 0xD8:
	//Debug.Log("Command DQT");
	return true;
	case 0xDD:
	Debug.Log("Command DRI");
	break;
	case 0xDA:
	Debug.Log("Command SOS");
	break;
	case 0xFE:
	Debug.Log("Command COM");
	break;
	case 0xD9:
	Debug.Log("Command EOI");
	break;
	}
	return false;
	}
	void SendFrame(byte[] bytes)
	{
	Texture2D texture2D = new Texture2D(2, 2);
	texture2D.LoadImage(bytes);
	//Debug.LogFormat("Loaded {0}b image [{1},{2}]", bytes.Length, texture2D.width, texture2D.height);
	if (texture2D.width == 2)
	return; // Failure!
	Graphics.Blit(texture2D, renderTexture);
	Destroy(texture2D); // LoadImage discards the previous buffer, so there's no point in trying to reuse it
	}
	}

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