[SDL] Video with SDL/OpenGL

Blake Senftner bsenftner at earthlink.net
Tue Jul 2 07:43:01 PDT 2002


From: "Jonathan Atkins" :
> Gib Bogle wrote:
>
> > When I play an MPEG-1 file (./glmovie test.mpg) I do not see anything
> > related to the content in this mpg file.  Instead I see a fixed image,
> > which happens to correspond to the bitmap of the NeHe logo, such as is
> > used in lesson06, which I was running yesterday.  In other words glmovie
> > is somehow locating the bitmap, which apparently still resides in RAM
> > somewhere, probably on the graphics card.  It is opening the mpg file
> > and returning correct mpeg_info.width and .height, but displaying
> > something else.  BTW, plaympeg plays the file OK.
>
> this could be related to a nonfunctional glTexSubImage2D perhaps...
> I've seen many a movie player use that function, even though it isn't
supported on every gfx card...
> mplayer has multiple methods of playing through OpenGL for just this
reason...
>

So, outside of visual observation how would the mpeg player know that
glTexSubImage2D() is not working?

If the function does not operate as advertised, then that OpenGL driver is
not compliant... (as if that matters in the big scheme).

Does one have to perform some glTexSubImage2D() operation, render the
texture, read it back in and THEN test to see if the glTexSubImage2D()
performed? (cuss deleted.)

-Blake






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