如何在不涉及中间服务器的情况下直接从 HTML 中输出 RTMP 视频

Question

I thought it is straightforward to establish an RTMP output stream from the browser directly to an RTMP server. It was looking possible to me when I saw some streaming video API providers offer ready-made iFrame urls that capture the PC camera and establish a stream with their servers when embedded in Html.

However - I was wrong.

It's pretty easy to get your hands on the chunks. But how to push them to RTMP server?

 navigator.getUserMedia({
       video: true,
       audio: true
 },

 function (stream) {

     var options = { mimeType: "video/webm; codecs=vp9" };
     mediaRecorder = new MediaRecorder(stream, options);

     mediaRecorder.ondataavailable = handleDataAvailable;
     mediaRecorder.start();

     function handleDataAvailable(event) {

       if (event.data.size > 0) {

         console.log(recordedChunks);

    } 
})

Answer 1

It's not possible.

Browsers do not support RTMP, nor do they allow for raw sockets required for adding support.

And RTMP does not support VP9, for what it's worth.

Answer 2

@szatmary correctly pointed out that browsers can't generate RTMP streams, and most likely will never be able to.

If you concatenate the buffers you get in your ondataavailable event handler, you get a media file in webm format. You can push the buffers one by one to a server using a web socket or socket.io. The server can assemble them into a file, which you can then play with many different media players, including the ones built into most browsers.

But webm data must be transmitted with TCP or another lossless net protocol. It is not resilient to the lost data packets inherent in datagram protocols like RTMP or RTSP.

You may want to use WebRTC with a so-called Selective Forwarding Unit server. Browsers can definitely originate WebRTC. And WebRTC is resilient to packet loss.

Some commercial vendors offer these services for a per-minute price. You can find various reviews on the intertoobz like this one. https://www.callstats.io/blog/2017/10/17/sdk-comparison

You might try one or two of these to see whether they meet your application needs. If they do, then you can make an informed "make vs. buy" decision.