Help with video streaming

RayDude · Posted: Wed Apr 20, 2005 7:58 am Post subject: Help with video streaming

I didn't think this little project would be so hard.

What I'm trying to do:

Using a Sony Web cam that produces a realtime http motion jpeg stream, I want to grab the data at about 1 MB/second off of ethernet, compress it in real time on a local server, down to about 128 kilobit/second and forward the stream to a linux server sitting on the internet (with unlimited bandwidth). The local installation is behind a firewall of a satellite uplink with very limited upstream bandwidth. I want to do this without impacting my friend's network bandwidth greatly.

This will allowing multiple (maybe 40?) users to view the web content coming from the web cam.

What I have working:

Using FFMPEG I can grab the data from the camera and compress it real time to a file on a local linux server.

However I cannot stream to a fifo which is set to forward to the internet server. ffmpeg simply does not like the fifo. ffmpeg can read from a fifo but doesn't seem to want to write to one.

I have Darwin Streaming Server set up on the local box and I figure if I can generate a mov, then it can forward it to a DSS instalation on the internet server without too much trouble, but I can't figure out how to link the streams...

Has anyone done anything like this?

Any advice would be greatly appreciated.

Thanks much.

Raydude
_________________
Some day there will only be free software.

richardash1981 · Posted: Wed Apr 20, 2005 3:40 pm Post subject:

lbrtuk · l33t Joined: 08 May 2003 Posts: 910

ffmpeg comes with something useful called ffserver.

http://ffmpeg.sourceforge.net/ffserver-doc.html

And read /etc/ffserver.conf for tips on configuring it.

(darwin streaming server would probably be overkill for this)

RayDude · Posted: Wed Apr 20, 2005 4:19 pm Post subject:

Thanks.

I tried doing it this way:

RayDude · Posted: Wed Apr 20, 2005 4:21 pm Post subject:

I saw this, but from what I gathered, it couldn't convert the mjpeg to mov and it wants files, not streams.

I'll read the docs in more depth and see what I can come up with. Thanks for the help.

lbrtuk · l33t Joined: 08 May 2003 Posts: 910

Shouldn't something like this work?

RayDude · Posted: Wed Apr 20, 2005 8:45 pm Post subject:

I'll try this tonight, great idea...

Will let you know.

RayDude · Posted: Thu Apr 21, 2005 4:44 am Post subject:

Close but no cigar.

Here's the command I figured out how to get mpeg1 to work with it, managed to stream to a file with this:

lbrtuk · l33t Joined: 08 May 2003 Posts: 910

Why do you have to use this wierd piping thing? Why does

RayDude · Posted: Thu Apr 21, 2005 5:06 pm Post subject:

Good question.

ffmpeg's mpeg codec does not support the YUV422 mjpeg output of the camera directly. I have to convert the mjpeg YUV422 to YUV420 and then compress it to mpeg.

If I try to convert it directly, as below, I get an error something like, "mpeg must be YUV420." Its interesting to note that it doesn't support 15 FPS either, I have to run 25 FPS for ffmpeg to encode mpeg...

lbrtuk · l33t Joined: 08 May 2003 Posts: 910

RayDude · Posted: Sun Apr 24, 2005 7:57 am Post subject:

mepg4 totally works... Thanks for that.

I can't get ffmpeg to forward to the server though. It looks like its working but no data is going.

and ffplay even though it will play .mp4 files will not play mpeg 4 when you use -f mp4 because it says that mp4 is unknown...

I started looking into gstreamer. Its probably exactly what I need, its just I was hoping to not have to write code to do this. I'm a hardware geek, C is not my forte.

However, if I can't ffserver to behave, I'll have no other choice.

Thanks for your help and if you think of any other ideas, I'd appreciate them very much,

Raydude

lbrtuk · l33t Joined: 08 May 2003 Posts: 910

Luckily you don't have to write any c code to get a custom gsreamer pipeline going. It comes with a little app called gst-launch that lets you build a pipeline on the commandline.

You should really be able to use any video player to play the stream from the server, eg- mplayer or xine. Or vlc for windows clients.

keli · Posted: Mon Jul 17, 2006 11:58 am Post subject:

any update on this? I'm trying to achieve something similar, though I have MPEG capable cameras (SONY SNC-RZ25, RZ50) at hand too.

It would be nice if I'd manage to pipe the streams to a Darwin (as I'm planning to use a darwin on the same project for other jobs anyway)
_________________
"The future masters of technology will have to be lighthearted and intelligent. The machine easily masters the grim and the dumb."
Marshall McLuhan, 1969

RayDude · Posted: Mon Jul 17, 2006 4:29 pm Post subject:

keli · Posted: Mon Jul 17, 2006 4:49 pm Post subject:

good tip, I'll need to look into that. I know VLC, as a media player, and I knew, "in theory" that it could stream, only so far I wasn't too successful with it.

Here's a bonus question, related both to IP cameras and VLC, then

Could I possibly use it to mux two separate (video and audio) streams from an IP camera?

The cam has http://192.168.0.100/mpeg4 for video and http://192.168.0.100/audio for audio streams. Unfortunately, the camera does not offer a possibility with the audio stream embedded in the video ...
_________________
"The future masters of technology will have to be lighthearted and intelligent. The machine easily masters the grim and the dumb."
Marshall McLuhan, 1969

RayDude · Posted: Mon Jul 17, 2006 5:36 pm Post subject:

keli · Posted: Wed Jul 19, 2006 9:39 am Post subject:

RayDude · Posted: Wed Jul 19, 2006 4:37 pm Post subject: