[MPlayer-dev-eng] libmpcodec and strides

[Nick Kurshev]

Hello, Arpi!

On Sun, 10 Mar 2002 15:16:03 +0100 you wrote:

> Hi,
> 
> > Which stuff should determine possibility of DR usage: libmpcodec or libvo?
> vd_*.c files set flags they support (like ACCEPT_STRIDE etc) and
> requirements they need (like READABLE, PRESERVE).
> then vd.c will call get_image() of libvo's control(), passing this mpi
> struct. the libvo driver can check if it can provide such buffer, then it
> sets stride + pointers and set DIRECT flag.
> this works fine with mga, xmga and xv drivers.
In many cases xv drivers accepts any strides (even when pitch == 1)
because it uses SW "C"-convertion yv12_to_yuy2.
You can find that looking at xc/Xserver/hw/xfree86/drivers/mga_video.c:

static void
MGACopyMungedData(...

So with vo_xv we always have double buffering mode through RAM with picth=1.
> 
> > Current implementation of libpcodec doesn't check this fact but old
> > dec_video did that?
> old dec_video didn't support DR at all.
> (except your hack but it worked only for width%16==0 and vidix)
No! The last version of my hack was acceptable for any picthes.
The 405.avi has width == 356 which can't be DR'ed even on radeons.
> 
> > In short: 405.avi with vidix+DR+dshow doesn't display correctly.
> > 
> > Indeed I can fix that within of vosub_vidix but before it was detected only 
> > once
> > within init_video_vaa() function. If it should be implemented in libvo drive
> > r then
> > those unnecessary compting will be performed for each frame.
> ?
Indeed, it's no question. Your voctrl_get_image provides much less info than bes_da_t
(which contains info about pitches) and in this connexion only way to compute possibility
of DR usage is in libvo.
> 
> 
> A'rpi / Astral & ESP-team
> 
> --
> Developer of MPlayer, the Movie Player for Linux - http://www.MPlayerHQ.hu
> _______________________________________________
> MPlayer-dev-eng mailing list
> MPlayer-dev-eng at mplayerhq.hu
> http://mplayerhq.hu/mailman/listinfo/mplayer-dev-eng
> 


Best regards! Nick
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 189 bytes
Desc: not available
URL: <http://lists.mplayerhq.hu/pipermail/mplayer-dev-eng/attachments/20020310/a0ceb5b7/attachment.pgp>