Using WebAPI to stream MJPEG always buffers - asp.net-web-api

Question

I'm using HttpSelfHostConfiguration to create a WebAPI (service). My goal is to have one route stream the mjpeg video from a security feed and have other routes available for configuration and the web interface.
The issue I'm having is that every example I've come across expects a known quantity of images in order to set the content-length for the main response. I don't have this, and flushing the stream doesn't do anything.
Here's the current code for the response. If I use this same code with raw sockets instead of through an ApiController, I can stream it just fine, but creating a webserver from scratch for everything else I'm needing doesn't seem like a lot of fun.
[HttpGet]
public HttpResponseMessage Stream(int channel)
{
var response = Request.CreateResponse();
response.Content = new PushStreamContent((outputStream, content, context) =>
{
StreamWriter writer = new StreamWriter(outputStream);
while (true)
{
using (MemoryStream ms = new MemoryStream())
{
ReadMemoryMappedFile(channel);
ms.SetLength(0);
this.Image.Bitmap.Save(ms, System.Drawing.Imaging.ImageFormat.Jpeg);
byte[] buffer = ms.GetBuffer();
writer.WriteLine("--boundary");
writer.WriteLine("Content-Type: image/jpeg");
writer.WriteLine(string.Format("Content-length: {0}", buffer.Length));
writer.WriteLine();
writer.Write(buffer);
writer.Flush();
}
}
});
response.Content.Headers.ContentType = System.Net.Http.Headers.MediaTypeHeaderValue.Parse("multipart/x-mixed-replace; boundary=--boundary");
return response;
}

Answer 1

I hope my late answer will help, since I ran into the same issue recently and it took me some time to figure it out...
My solution was to specify the boudary int the ContentType without the "--" (but you need to keep them while writing in the stream).
Try to configure the Headers like that :
response.Content.Headers.ContentType = System.Net.Http.Headers.MediaTypeHeaderValue.Parse("multipart/x-mixed-replace; boundary=boundary");
And write boundaries in the stream like that :
writer.WriteLine("--boundary");
Like this it works for me.

Answer 2

I couldn't find anywhere that explicitly states this, but I'm going to assume that HttpSelfHostConfiguration does not support the functionality I'm looking for, and always requires the stream to be closed before it will release the buffer.
I swapped HttpSelfHostConfiguration with OWIN.SelfHost and it works as expected.