Justin Schoeman wrote: > > Gunther Mayer wrote: > > > > Hi, > > > > the 1st line of the tv picture is constantly dashed here, e.g. > > - - - -- - -- -- - - -- -- ---------------------- > > > > This is a cosmetic problem but nevertheless annoying ! > > I think this problem existed since the early days of bttv. > > > > Do others see this artefact, too? > > Any clueful hints on causes for this? > > > > Regards, Gunther > > > > P.S. > > Further data/Kind-of-Workaround: > > When switching to "grabdisplay" in the default size 384x288 > > the line is fine (and the pictures increases sligtly in size, > > both horizontal and vertical) ! > > > > This does not help as soon as vsize>288, so this could be > > a subtle scaling problem in the BTTV-Risc code or similar? > > > > Side note: With "grabdisplay" unfortunately the last line is wrong:-( > > | ------------------- | > > > > The artefacts combination depends on the tv channel selected: > > RTL (CH60) in the only channel without artefacts, here! > > I am pretty sure the operation of bttv is correct. The problem comes > in, because bttv will capture the ENTIRE video image (including the > half-line scans). Many broadcasters transmit some information (looks > like a timestamp to me) in the first half of the first visible display > line, and this is probably what you are seeing. Analog TVs cut off the > top, bottom, and borders of the visible image, so you don't usually see > this. This doesn't explain why "grabdisplay" is different from "overlay". If you are right about ill-use of the first line (and the last line, too), of course these lines should (optionally) not be shown in xawtv ! Ralf ? Regards, Gunther
