[FFmpeg-user] drawtext to a (transparent) bounding box
jannes.faber at gmail.com
Fri Feb 27 18:54:11 CET 2015
Using drawtext on a transparent background does not seem to work.
On 23 February 2015 at 17:55, Jannes Faber <jannes.faber at gmail.com> wrote:
> Video editting newbie here.
> I'm trying to use addtext onto a box and then overlay that box on a video.
> That works fine, except when I try to make the bounding box transparent.
> The problem is that the text itself becomes transparent too, not just the
> bounding box.
> I asked this question here and included some screenshots and example code:
> The very helpful comment I got so far:
> "I think what's happening is that drawtext isn't writing the alpha
> channel, so overlay just sees a rectangle with uniform alpha. The opacity
> controls for drawtext just affect how it blends its text into the frames it
> draws on." - Peter Cordes
> It feels a bit like a bug in ffmpeg to me, but I'm sure there's a good
> explanation. And I'm wondering if there's another/better way to do it?
> Thank you.
More information about the ffmpeg-user