Date: Fri, 5 Nov 1999 18:18:40 -0500 From: Randall Hopper <aa8vb@ipass.net> To: marc rassbach <marc@tandem.milestonerdl.com>, Amancio Hasty <hasty@rah.star-gate.com> Cc: freebsd-hardware@FreeBSD.ORG, multimedia@FreeBSD.ORG, Roger Hardiman <roger@cs.strath.ac.uk> Subject: Re: bt848 w/ 3.3 Message-ID: <19991105181840.A1124@ipass.net> In-Reply-To: <Pine.BSF.4.05.9911042307560.86480-100000@tandem.milestonerdl.com> References: <Pine.BSF.4.05.9911042307560.86480-100000@tandem.milestonerdl.com> <199911050422.UAA51410@rah.star-gate.com> <199911050341.TAA51090@rah.star-gate.com> <Pine.BSF.4.05.9911042307560.86480-100000@tandem.milestonerdl.com>
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Amancio Hasty: |marc rassbach: |> Also, keep in mind that the BT series of chipset seem to have a problem |> where the odd and even frame get confused. (The chipset puts the odd |> where the even should be and visa versa.) | |This is a bug in the driver and not on the chipset unless of course |you can prove me wrong 8) Are we sure that this is really a bug? I've heard ruminations before but nothing more. We should keep in mind that NTSC does not raster scan two interlaced fields of a "freeze frame" 30 times per second. Time goes on as the raster scans the first field, and then retraces to scan the second. The time difference between fields of course equals 1/60th of a second. TV has long persistence phosphors, so even during fast motion sequences, the differences in the fields isn't as apparent as it is on a computer monitor where both the phosphor persistence is shorter and the spatial resolution is a good bit higher. I think this may account for the difference we see. To demonstrate, zoom the TV (right click in fxtv), and freeze frame on a scene while a pure-color computer overlay sweeps across the display. There is significant difference between the fields of course. But (because they are pure colors), its very easy to see that switching the fields is not going to make any difference. The fields are just very different What would be interesting is to know whether the same is visible in the MS Windows apps. If not, wonder if the bt848 has some temporal filtering/interpolation feature which they have turned on and we don't. Randall To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-multimedia" in the body of the message
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