How do I implement DeviceSource for streaming from webcam in Live555? - c++

I am working on a webcam streaming server project, using Live555 as the server.
I need to be able to stream from ordinary USB Webcams, which requires me to implement DeviceSource.cpp as I read on live555's FAQ page. However, I am currently not having enough knowledge or clue on how to implement this.
I intend to use ffmpeg as the encoder.
Can anybody provide me with some proper directions that I can follow?

Related

How to create a video streaming httpserver?

I'm using c++ and poco libraries. I'm trying to implement a video streaming httpserver.
Initially i used Poco::StreamCopier.
But client failed to stream.
Instead client is downloading the video.
How can i make the server to send a streamresponse so that client can stream the video in browser instead of downloading?
While not within POCO, you could use ffmpeg. It has streaming servers for a number of video protocols and is written in C (which you could write POCO-like adapters for).
http://ffmpeg.org/ffmpeg.html#rtp
http://ffmpeg.org/ffmpeg.html#toc-Protocols
http://git.videolan.org/?p=ffmpeg.git;a=tree
And it has a pretty liberal license:
http://ffmpeg.org/legal.html
You need to research which video encoding and container that is right for streaming -- not all video files can stream
Without using something to decode the video at the other end but simply over HTTP, you can use The mime encoding "content-type:multipart/x-mixed-replace; boundary=..." and send a series of jpeg images.
This is actually called M-JPEG over HTTP. See: http://en.wikipedia.org/wiki/Motion_JPEG
The browser will replace each image as it receives it which makes it look like it's video. It's probably the easiest way to stream video to a browser and many IP webcameras support this natively.
However, it's not bandwidth friendly by any means since it has to send a whole jpeg file for each frame. So if you're going to be using this over the internet it'll work but will use more bandwidth than other method.
However, It is naively supported in most browsers now and it sounds like that is what you're after.

Display streaming video in desktop app

I have a Windows native desktop app (C++/Delphi), and I'm successfully using Directshow to display live video in it from a 'local' video capture device.
The next thing I want to do is display video from a 'remote' capture device, streamed over the LAN.
To stream the video, I guess I can use something like Expression Encoder or VLC, but I'm not sure what's the easiest way to receive/decode the streamed video. Inserting an ActiveX VLC or Flash player might be one option (although the licensing may be an issue then), but I was wondering if there's any way to achieve this with Directshow...
Application needs to run on XP, and the video decoding should ideally be royalty free.
Suggestions, please!
Using Directshow for receiving and displaying your video can work, but the simplicity, "openness" and performances will depend on the video format and streaming method you'll be using.
A lot of open/free source filters exist for RTSP (e.g. based on live555), but you may also find that creating your own source filter is a better fit.
The best solution won't be the same for H264 diffusion through RTP/RTSP and for MJPEG diffusion through simple UDP.

Designing live video stream for wxWidgets

In my application we will present the video stream from a traffic camera to a client viewer. (And eventually several client viewers.) The client should have the ability to watch the live video or rewind the video and watch earlier footage including video that occurred prior to connecting with the video stream. We intend to use wxWidgets to view the video and within that we will probably use the wxMediaCtrl.
Now, from the above statements some of you might be thinking "Hey, he doesn't know what he's talking about." And you would be correct! I'm new to these concepts and I confused by the surplus of information. Are the statements above reasonable? Can anyone recommend a basic server/client architecture for this? We will definitely be using C++ wxWidgets for the GUI, but perhaps wxMediaCtrl is not what I want... should I be directly using something like the ffmpeg libraries?
Our current method seems less than optimal. The server extracts a bitmap from each video frame and then waits for the single client to send a "next frame" message, at which point the server sends the bitmap. Effectively we've recreated our own awkward, non-standard, inefficient, and low-functionality video streaming protocol and viewer. There has to be something better!
You should check out this C++ RTMP Server: http://www.rtmpd.com/. I quickly downloaded, compiled and successfully tested it without any real problems (on Ubuntu Maverick). The documentation is pretty good if a little all over the place. I suspect that once you have a streaming media server capable of supporting the typical protocols (which rtmpd seems to do), then writing a client should fall into place naturally, especially if you're using wxWidgets as the interface api. Of course, it's easy to write that here, from the comfort of my living room, it'll be a different story when you're knee deep in code :)
you can modify your software such that:
The server connect, server grabs an image, passes it to ffmpeg establishing stream, then copy the encoded data from ffmpeg stream and send to client via network, if the connection drops, close the ffmpeg stream.
Maybe you can use the following to your own advantage:
http://www.kirsle.net/blog.html?u=kirsle&id=63
There is a player called VLC. It has a library for c++ and you can use it to embed the player in your GUI application. It supports a very wide range of protocols. So you should leave connecting, retrieving and playing jobs to VLC and take care of the starting and stopping jobs only. It would be easy and probably a better solution than doing it yourself.
For media playing facility, both music and audio, you can a look on GStream. And talking about the server, I think Twisted (A network library in Python) should be good option. The famous live video social website justin.tv is based on Twisted. Here you can read the story from here. Also, I built a group of server for streaming audio on Twisted, too. They can serve thousands of listener on line in same time.

Play RTP video stream using Qt?

I want to create a Qt widget that can play incoming RTP streams where the video is encoded as H264 and contains no audio.
My basic plan for implementation is this:
Create a Phonon MediaSource object (Stream type).
Connect it with a QIODevice subclass that provides the data
Obtain the video data using either:
The JRTPLIB client library
The GStreamer gstrtpbin plugin. This plugin takes care depayloading the packages and decoding the video. Maybe this improves the chances that Phonon will recognize the data.
My environment:
Ubuntu 9.10
Qt 4.6
My questions:
Is my approach a good one? Perhaps I'm overlooking a more obvious or simple solution?
I'm currently experiencing this issue: when trying to play the video stream the state of the MediaObject turns to ErrorState with errorType FatalError. Can anyone tell me what I'm doing wrong?
Edit
One solution I found is using libVLC in combination with Qt, which I learned about in this thread. Here's a code sample for the interested.
I'm still looking for a Phonon-based solution.
Ideally I would only need to provide an SDP file and job is done.
I was able to get it to work using the libVLC solution. I can't garantuee that this is the best solution though as I simply stopped looking after that.
Here's a link to the libVLC sample.
The way I understand Phonon works at least in Windows is that QT provides a phonon backend plugin for DirectShow (\plugins\phonon_backend\phonon_ds94.dll) and GStreamer in your case. Then you would either obtain or write your own DirectShow filter which can accept RTP streams as a source. DirectShow takes care of the decoding, and Phonon will take care of the rendering.
So if the backend works, the application code is as simple as:
Phonon::MediaObject *media = new Phonon::MediaObject();
Phonon::VideoWidget *video = new Phonon::VideoWidget();
Phonon::createPath(media, video);
media->setCurrentSource(source);
media->play();
Seems that the problem lies with the GStreamer backend accepting RTP as a source. Can you playback that source in standalone GStreamer without any problems?

How can I stream video from my application to the web?

I have an application that grabs video from multiple webcams, does some image processing, and displays the result on the screen. I'd like to be able to stream the video output on to the web - preferably to some kind of distribution service rather than connecting to clients directly myself.
So my questions are:
Do such streaming distribution services exist? I'm thinking of something like ShoutCAST relays, but for video. I'm aware of ustream.tv, but I think they just take a direct webcam connection rather than allow you to send any stream.
If so, is there a standard protocol for doing this?
If so, is there a free library implementation of this protocol for Win32?
Ideally I'd just like to throw a frame of video in DIB format at a SendToServer(bitmap) function, and have it compress, send, and distribute it for me ;)
Take a look at video LAN client (or VLC for short) as a means for streaming video.
As for distribution sites, I don't know how well it works with ustream.tv and similar new services.
ustream.tv works by using Adobe Flash's support for reading input from a webcam. To fake it out, you need a fake webcam driver. Looking on the ustream.tv site, they point to an application called WebCamMax that allows effects and splicing in video. It works by creating a pseudo-webcam that mixes video from one or more cameras along with other sources. Since that app can do it, your own code could do that too, although you'll probably need to write a Windows driver to get it all working correctly.