RE: [xine-devel] Re: [xine-user] zoom

[James Courtier-D. <Ja...@su...>]

What about letterbox pictures encoded in 4:3 frames with top and bottom
black borders.
A 16:9 TV will just put a 4:3 frame in the centre.
If the image is a letterbox image, you will then get borders on top, bottom
and left and right,
because video out driver will think it is a 4:3 frame.
If we could introduce a new aspect ratio which could expand letterbox 4:3
images to full screen 16:9, I think it could be useful.
Cheers
James



> -----Original Message-----
> From: xin...@li...
> [mailto:xin...@li...]On Behalf Of Harm van der
> Heijden
> Sent: 28 October 2001 23:13
> To: xin...@li...
> Subject: [xine-devel] Re: [xine-user] zoom
>
>
> On Sun, Oct 28, 2001 at 10:26:05PM +0100, Torgeir Veimo wrote:
> > I've bought the latest box set of movies by Stanley Kubrik,
> which are in
> > 1:1.33 format, but more like 1:1.77 inside this format. Thus it
> would be
> > nice to be able to zoom in to avoid most of the letterbox effect.
>
> Most video out drivers should be able to cope with removing black borders.
> For YUY2 data it involves something like out_ptr = src + top_lines*width*2
> and out_height = height - top_lines - bottom_lines, if you get my drift.
> YV12 is similar, with factors /4 for U and V.
>
> Removing bits on the left and right of the picture is not really
> an option,
> as it would require video out drivers to have a sense of stride (distance
> between horizontal lines). Some, if not most, require that stride
> == width.
>
> My guess, and I'm not hampered by any real knowledge of how Xv and XShm
> drivers work, is that it would be fairly easy to add a hack for cutting
> X lines at the top and Y lines at the bottom. A more general xine solution
> would be more work.
>
> BTW, in the new dxr3enc driver, I'm doing the exact opposite: the dxr3
> hardware only supports 16:9 and 4:3, and in order to display square
> pixel video (read AVI) correctly I add black lines until I get to the
> closest supported a.r. It's all done with pointer offsets (I allocate
> more YUV memory than the decoder sees, and blacken out the borders
> in advance). Again, this trick only works with top and bottom borders.
> Stuff at the side is not possible with the current xine architecture
> (at least not without costly copy operations), due to the stride thing.
>
> Regards,
>
> Harm
>
>
>
>
>
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