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libVLC - vmem - Delay?

Posted: 18 Feb 2009 17:23
by MysticX
Hello there,

I'm using libVLC in a Windows C++ application. Currently, I'm using the vmem output module in order to access uncompressed data coming from a live webcam streaming over the network (using also VLC as a capture software and encoder). I successfully managed to reduce the delay in order that the stream is displayed correctly while streaming from my application to VLC. However, using the same settings (I load a config file), I get much larger delays in my application (two or three times bigger, haven't measured them precisely). I don't see where the delays could be in my application - I only grab the data from the memory and display it using DirectShow, very simply.

Is there a known issue about the libVLC and vmem module (I know it's still somewhat new) about delay? Is there parameters that could be ajusted for the vmem module (such as a vmem-delay or something like that)?

Thanks in advance!

Re: libVLC - vmem - Delay?

Posted: 29 Aug 2009 03:37
by willywang
would you please send me the sample code on how to use vmem to grab raw picture data, Thanks a lot,since I'm new ahout it actually.

Re: libVLC - vmem - Delay?

Posted: 29 Aug 2009 10:57
by RĂ©mi Denis-Courmont
vmem does not implement the pf_display callback that specifies when the picture must actually be displayed. Unavoidably, pf_lock is called ahead of time, and pf_unlock late.

There is no way to work around this other than patch the vmem module.