[vlc-devel] subpicture channels and vout_ShowTextAbsolute

Antoine Cellerier dionoea at videolan.org
Fri May 23 17:20:01 CEST 2008

On Thu, May 22, 2008, jboileau wrote:
> I am trying to implement an API to display text over the video. I am
> trying to use vout_ShowTextAbsolute which seems to be the right
> candidate for the job. But the concept of channels is a bit obscure to
> me. My needs are to have more than one zone of text. For example lets
> say I want text in the four corners. If I call vout_ShowTextAbsolute
> with the correct flags for the 4 corners but use DEFAULT_CHAN for the
> channel (which is 1), only the last corner set will have text the
> others will probably have been deleted by the subsequent calls to
> vout_ShowTextAbsolute. If I use 2 as the channel number for all 4
> calls I will then see all my text in each corner. If I try using other
> channel numbers nothing is displayed. Can someone shed some light on
> subpicture channels? Is vout_ShowTextAbsolute the way to go to display
> overlaid text?

The best way I can think of is the marq subpicture filter. You don't
need to change any code to use it.

vlc --sub-filter marq somevideo.mpg

See for all the options:

Antoine Cellerier

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