On Thu, 18 Oct 2001, Billy Biggs wrote: > Hi Mark (and list), apologies for keeping traffic so high, but I have > another question about XVideo and it's just too useful. :) > > Say I'm attemping to play 525/59.94 video (identical problem exists > for 625/50 systems). Ideally, I want to do software deinterlacing and > output full 720x486 images at 59.94fps. However, PCs are still slow, so > my application has three choices: > > a) full resolution 59.94 deinterlaced, > b) half-resolution 59.94 (using Xv for scaling up each field), > c) full-resolution 29.97 deinterlaced. > > Dealing with (a) and (c) is easy, but (b) is ambiguous. I see two > basic methods: > > Method 1: Create Xv images of size 720x240. Make sure the scaling of > the window is such that input scanlines are aligned to output scanlines. > > o Blit top fields to x,y of 0,0, w,h of 720,485 (scaled) > o Blit bottom fields to x,y of 0,1, w,h of 720,486 (scaled) > > Problems: > > 1) Since I usually get input as frames, I need to do an extra copy to > split the input into the two field buffers. This is really, really > awkward since at least for DVDs we often switch between progressive > and interlaced input. With the i810 at least, any time I start > blitting images of a new size, the card resets and I get a few bad > frames blit before it wakes up! :( (is this a bug?) > > It seems to me that the Xv API could have benefited from a pixel > stride parameter for blits. Is this fixable?
It's possible for the driver to offer a port attribute with top/bottom. Maybe it's best that it's write only and applies only to the next command. It could work like a hint for the next PutImage. XvMC has explicit top/bottom/frame instructions in the Put command. Mark. _______________________________________________ Xpert mailing list [EMAIL PROTECTED] http://XFree86.Org/mailman/listinfo/xpert