HttpWebResponse with MJPEG and multipart/x-mixed-replace; boundary=--myboundary response content type from security camera not working

Question

I have an ASP.NET application that I need to show a video feed from a security camera. The video feed has a content type of 'multipart/x-mixed-replace; boundary=--myboundary' with the image data between the boundaries. I need assistance with passing that stream of data through to my page so that the client side plugin I have can consume the stream just as it would if I browsed to the camera's web interface directly. The following code does not work:

//Get response data
byte[] data = HtmlParser.GetByteArrayFromStream(response.GetResponseStream());
if (data != null)
{
 HttpContext.Current.Response.OutputStream.Write(data, 0, data.Length);
}
return;

Answer 1

Well, if you want your client to see the mjpeg stream, you need to send the whole http response. HTTP client like browser or media player like VLC need a mjpeg stream that looks like :

HTTP/1.1 200 OK
Content-Type: multipart/x-mixed-replace; boundary=myboundary

--myboundary
Content-Type: image/jpeg
Content-length: 12345

[image 1 encoded jpeg data]


--myboundary
Content-Type: image/jpeg
Content-length: 45678

[image 2 encoded jpeg data]

...

NOTE: As Ergousha said in an answer, you must have an empty line after the Content-length field.

By the way, why not redirect your client directly to the mjpeg stream ?

You can use http://ipcam/mjpg/video.mjpg AXIS IP cameras for example.

If you just need the image through HTTP, you have to set the correct header and the MIME content-type image/jpeg. To decode the image, you have to get the byte data and you will get jpeg encoding. Then you will have to decode jpeg to get an image in a specific format (something like yuv420p I think). I've check on my ip camera, and its stream is not base64 encoded I think.

Precise your needs, I will try to help more.

my2c

EDIT:

Well, I suppose you do something like :

client    : connect to proxy, 
            get example.com/camera1.mjpg,
            while not the end
                recv


yourproxy : wait connection
            connect to camera,
            get 10.0.0.123/camera1.mjpg
            while not the end
                recv buffer
                copy buffer
                send buffer to client

That to say that you must send the correct header to your client. To be sure use a tool like wireshark to spy on the packet and be sure that after your client has issued a HTTP GET you send to him the correct MJPEG stream (like the one I describe at the beginning of my post ...)

m2c

Answer 2

Good explaination about how mjpeg stream looks like. I would like to add a tip that; there are always 2 new line character before the actual data. If you make it one line, it doesnt work.

        string header =
            "--myboundary\r\n" +
            "Content-Type:image/jpeg\r\n" +
            "Content-Length:" + length.ToString() + "\r\n\r\n";