Live encoder for screen cap?

[sethbb]

I've done some live screen cap broadcasting with windows media encoder to wm server, but latency of 24+ seconds makes it inappropriate for some uses.

New to the wowza environment - can anyone recommend an encoder for live broadcast of a PC screen or screen region?

[charlie]

Telestream Wirecast has a plugin that does this.

Charlie

[Florent.T]

You can

• use a scan converter + analog encoder
• use software-based capture (vnc, vlc+vhscrcap, FME+vhscrcap)
• for hardware capture + directshow integration, check out epiphan's VGA2USB
• as for fully hardware-based h264 encoder, there is no such thing as this time

[sethbb]

Thanks for these suggestions, they give me some starting points.

Wasn't aware of the screencap plugin for Wirecast - sounds promising.

You can

• use a scan converter + analog encoder
• use software-based capture (vnc, vlc+vhscrcap, FME+vhscrcap)
• for hardware capture + directshow integration, check out epiphan's VGA2USB
• as for fully hardware-based h264 encoder, there is no such thing as this time

A good screencap is going to stay in the digital domain through to live webcast distribution, isn't it?, but I will take a closer look at FT's software suggestions. I knew VLC would do this, but comments about instability with Wowza in the sticky above put me off.

VNC? FME+vhscrcap? I didn't see those in the sticky threads for live encoders, but will check them out. FT, I'm looking for an encoder specifically to exploit Wowza's low-latency live broacast mode for a PC screen show, targeting 15fps.

********edit***********
VNC, realVNC, tightVNC, etc. don't seem to support the kind of framerates I'm looking for, and open up more functionality than I want to give to users. FME+vhscrcap looks deserving of some trials & benchmarking, as does wirecast.

[Florent.T]

vhsrcap being a directshow filter, you can use it with both VLC and Flash Media Encoder.

15 fps will be really hard to get on software, especially if you expect to do HD-like. As usually desktop is in high res (thus, apps are too --> unsuitable to screen video capture), vhscrcap's cursor tracking features might be a nice addition. Moreover, you most probably won't find hardware-based cursor tracking.

Btw, i'm not affiliated to hymeloff labs in any sense, just used it for dev purposes and it was quite stable. Need some horsepower though...

Alternatively, you can take a look at haivision's Mako HD which has VGA input (but 10k$). If anyone knows a better solution, ...

[sethbb]

Thanks for the suggestions and followup.

I'm working 8fps at 1200x700 on windows media encoder with an external wm server host, using the WM9 screen codec with a limited color pallette at about 370Kbps, hoping for improvements from a wowza solution. Actually, if I could replicate this performance with only a few seconds of latency it would be a big win, as I can't directly manage the WM server to adjust/optimize its built-in default latency of about 24 seconds.

Unfortunately no time today to go right into benchmarking

I suppose codec performance is also going to be an area to investigate, both for the originating box and out of server...

[dpMediaDev]

vhsrcap being a directshow filter, you can use it with both VLC and Flash Media Encoder.

Well, this seems to be a really nice solution. But it does not really work in FME 3 here. I can see the preview screen before I start the streaming to the server or to a local file. But if I press start nothing gets captured and the bitrate encoding statistics of audio and video are 0 all the time.

Sincerely,
Robin