The VideoLAN Forums

I noticed that there is about a 2 second delay in streaming content.

I was thinking about using VLC as an alternate to VNC, as a way of having a thin client and a central server. That is on a dual or quad processor system, with VLC running and capturing the screen and streaming it, and the other processors doing media, 3d graphics, or games. Using Synergy (http://synergy2.sourceforge.net/) for mouse and keyboard.

I'm using VH Screen Capture driver, for the screen capture http://www.hmelyoff.com/.

In testing this out, I set up a UDP stream and I noticed a 2 second delay. It's not the capture device, if I open the capture device there is only a few frames lag. It's not my network, because I've tried it via local host (127.0.0.1). I tried different codecs for transcoding the stream, but there was no difference.

Any ideas what this is, is it transcoding or is it part of UDP or something else?

There is some caching when streaming in UDP with VLC that you could try to decrease. Have a look at the preferences there (with Advanced options checked off):
- Stream output -> Access output -> UDP (for your server)
- Input/Codecs -> Access modules -> UDP/RTP (for your client)

Default caching is 300ms for both of them, so you could theoretically save a 600ms delay with these settings...

Thanks!!! That definetly sped it up by 600ms! The delay was about 1900ms, now its about 1300ms. I wonder what the rest of the delay could be. I'll look at the other settings, see if there is anything obvious.

There is another thing I notice. For the DirectShow settings there is a delay that defaults to 200ms. If I set this to zero, then the display is more snappy (maybe down to the minimal 1 frame delay). This works fine when I simply view it in VLC, but if I stream it with this setting, the recieving client at some point stops updating. And it seems like 200ms is a magic number, everything below it eventually causes the client to stop updating.

Hello - I am very interested in the answer to this as well. I am trying to use two DV camcorders (WinXP, directshow) in a videoconferencing application. The video looks good but delayed by the afore-mentioned 2 seconds. Interestingly, under vlc 8.2 I could not get the video to stream at all unless I set the direct show caching value to 0. As Nine mentions, 8.5 seems to like a value of 200

Hello

how can we set the same options using the comman line ?

thanks

The delay exists! I try to stream in HTTP and delay is 2 sec. It's not a UDP issue.
Please help!

Thank you.

There is some caching when streaming in UDP with VLC that you could try to decrease. Have a look at the preferences there (with Advanced options checked off):
- Stream output -> Access output -> UDP (for your server)
- Input/Codecs -> Access modules -> UDP/RTP (for your client)

Default caching is 300ms for both of them, so you could theoretically save a 600ms delay with these settings...

Are these settings related to any command parameters? What do we have to do in command line?

All command line functions (syntax) may be found by typing vlc -H on the command line in the VLC folder.

I believe you will find that by eliminating all the delays (buffering), streaming will be impossible! but you are most welcome to try.