[gst-devel] import image with transparent background

[Terry Leung]

Hi,

I've just complied the plugin you mentioned

The src caps are as following:
  SRC template: 'src'
    Availability: Always
    Capabilities:
      video/x-raw-rgb
                    bpp: 24
                  depth: 24
             endianness: 4321
               red_mask: 16711680
             green_mask: 65280
              blue_mask: 255
                  width: [ 1, 2147483647 ]
                 height: [ 1, 2147483647 ]
              framerate: [ 0/1, 2147483647/1 ]
      video/x-raw-rgb
                    bpp: 32
                  depth: 32
             endianness: 4321
               red_mask: -16777216
             green_mask: 16711680
              blue_mask: 65280
             alpha_mask: 255
                  width: [ 1, 2147483647 ]
                 height: [ 1, 2147483647 ]
              framerate: [ 0/1, 2147483647/1 ]

The src of it is still raw rgb(without alpha). If then , how can i use
the alpha channel of a png image?

Regards,
Terry

On Jan 3, 2008 8:34 PM, Terry Leung <terry83 at gmail.com> wrote:
> HI,
>
> I am using png and have used gst-inspect to inspect the caps of some
> common format like bitmap, jpeg and png
> It dosnt matter for what decoder to use. I just need the program to
> load a common format picture with transparent background and overlay
> the image on top of a video.
>
> By the way, any program that support output a gdkpixbufdec picture or
> convert a png with alpha channel to this format?
>
> Regrads,
> Terry
>
>
> On Jan 3, 2008 5:57 PM, Tim Müller <t.i.m at zen.co.uk> wrote:
> > On Thu, 2008-01-03 at 10:41 +0800, Terry Leung wrote:
> >
> > Hi,
> >
> >
> > > I am now writing a program to overlay an image on top of a video clip
> > >
> > > However, as I want to overlay an image with transparent background and
> > > those image decoder src pad are either raw rgb or raw yuv(without
> > > alpha), I want to ask how can i do that? can gstreamer support the
> > > transparent feature in some type of image(like png or gif)? and how?
> >
> > Which image decoder exactly? What format is your image in?
> >
> > IIRC, gdkpixbufdec outputs RGBA if the image has an alpha channel.
> >
> >  Cheers
> >   -Tim
> >
> >
> >
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