Can I butt in with some basic questions? I'd just like to understand what kinds of applications will benefit from this proposal.
We have lots of DVD players, the ubiquitous Brooktree framegrabber, and esoteric stuff like my ADV601. I know for sure it would help me. The Bt chips normally produce 25/30 interlaced frames/sec which might look lousy when displayed if there is horizontal motion. They can be programmed to decimate the frame, so you would only see say 25/30 even fields/sec Can they also be programmed to deliver 50/60 fields/sec? Does v4l support all this? Do v4l apps usually have the Bt chip writing the YUV image directly into video memory? Would Xv, or the graphics driver support odd/even fields in this case? DVD players I know nothing about. What do they do? -- Paul ----- Original Message ----- From: "Mark Vojkovich" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Friday, May 10, 2002 11:34 PM Subject: Re: [Xpert]Using Xv to display odd/even fields from a TV camera > On Fri, 10 May 2002, Billy Biggs wrote: > > > The delay stuff is less important than the field flag. > > > > Mark Vojkovich ([EMAIL PROTECTED]): > > > > > I'd like an XV_FIELD (or better named) attribute that indicates the > > > next PutImage request should upload and display the field rather than > > > the frame which is the default. "0" is top, "1" is bottom, per mpeg > > > conventions. It's a one-shot state that gets reset to frame after the > > > next PutImage happens. > > > > How does this work for full 50 or 59.94fps video? Do I upload the > > same frame twice, or does this attribute just mean: only copy from the > > source frame the even/odd field, so that the whole frame isn't coped > > twice, only half of it? > > It means that only the field is copied and only the field is > displayed. > > > > > > I'm also worried about switching from frame-mode to field-mode. In my > > DVD player for example, I'll switch between 3:2 pulldown correction in > > software, or, if I lose the phase, go back to 60fps output. Do you > > think video cards are going to have a problem switching the scaling > > width/height without artifacts? > > NVIDIA cards won't have a problem with this. I think some cheaper > cards that don't double buffer their registers and have to be programmed > during the retrace won't be able to do this very well. > > > Mark. > > _______________________________________________ > Xpert mailing list > [EMAIL PROTECTED] > http://XFree86.Org/mailman/listinfo/xpert _______________________________________________ Xpert mailing list [EMAIL PROTECTED] http://XFree86.Org/mailman/listinfo/xpert
