Re: DVDPlayback

FROM : Michael Ash
DATE : Sat Jul 08 17:50:12 2006

On 7/6/06, <email_removed> <<email_removed>> wrote:
> cocoa-dev:
>
> While the  CocoaDVDPlayer sample works fine for basic playback of a dvd or
> VIDEO_TS folder, it isn't very helpful when trying to go a little further.
>
> Specifically, I need to be able to have DVDKit draw the video into a
> gworld or other offscreen buffer so that I can draw it in a view in my
> application's window, allowing the window to contain other content.
> There's a DVDSetVideoPort(), which I thought I would be able to pass a
> gworld too, but it looks like it needs a display device id as well, as
> though it's trying to force the dvd content to be drawn only in an
> onscreen window. Also, since I can't debug the app (quits with error 45
> when run with gdb, I assume this means "licensing prevents debugging of
> dvd apps"), it makes it hard to figure out what's going on.
>
> Furthermore, I'd also like to have more access to the actual video, such
> as to find the number of samples (frame), and the locations of keyframes.


I'd be surprised if you could make this work in any simple manner.

DVDs contain a whole lot of DRM meant to prevent copying. This means
that (legal) DVD playback applications do various tricks to cooperate
with this DRM. For example, last I checked, DVDPlayer.app's video
content did not appear in screenshots taken with the built-in
screenshot mechanism. It is of course possible to get around this and
take a screenshot anyway, but you have to get into dirty tricks.

What you're describing is almost exactly what you would need to write
a very easy DVD ripper. (I'm not saying that *is* what you're writing,
but what you want to do and what you would need to do for that are
almost identical.) It follows that the DVDPlayback framework won't
easily allow you to render the video to any location where you could
get the pixel data back out.

If you want to include other controls in the playback window, I
suggest looking into putting the playback into a child window, with
the parent window containing the controls.

Mike