[vlc-devel] How to modify video output?

Juha Jeronen juha.jeronen at jyu.fi
Mon Sep 26 10:46:51 CEST 2011


On 09/26/2011 09:57 AM, Peter Tap wrote:
> Folks,
> After implementing a stream_filter module, I have become a bit
> comfortable with vlc development environment.
> Now, I have a new task. At a specific time during an mp4 media is
> being played, I need to draw a thumbnail image at a certain location
> over the underlying video image. The image should disappear after a
> few seconds.

If I recall correctly, VLC does something like this when a snapshot
(video screenshot) is saved, so you may be able to get some pointers on
how to do it from that code.

Basically, you need to draw the pixels of the thumbnail into the video
buffer, using the same colour format (e.g. I420) as the video being
played does.

> I am wondering what type of module do I need to develop.

I suggest a video filter module. Source directory modules/video_filter,
API name "video filter2". There's some development documentation on this
in the wiki:


If you find the doc is missing some information, ask on this list for
help. I'll then update the wiki if someone knows and posts the answer.

 -J (author of the "IVTC" and "Phosphor" deinterlacers)

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mailman.videolan.org/pipermail/vlc-devel/attachments/20110926/9a7b90ff/attachment.html>

More information about the vlc-devel mailing list