Justin Schoeman wrote: > > Ivor Cox wrote: > > > > Further tests indicate that the data for a capture (I am using mmap) is > > incomplete and confused by the remains in the buffer of the previous image. > > The incompleteness has a pattern which results in the grid I explained - but > > the image I get is a mixture of the latest and earlier images. > > > > If I have not waited correctly for sync or am reading the wrong buffer > > (effectively the same!) would I get an effect like this? > > > > BTW the image I see is undistorted so I am sure the RGB format is correct - > > it's just got bits missing in a near-regular pattern. > > > > Ivor > > This sounds like the PCI latency effects again. Try playing with the PCI > latency timers in your BIOS setup. > Hmm... Ivor, does this happen for all image sizes, or only above half size vertical? Above half size bttv gives you an interlaced image where alternate lines in the image are from the odd and even frame. I've seen a problem before (do you remember Justin? - I sent you a test program and you were able to duplicate it) where the DMA engine stopped transferring one of the odd/even frames with the result that there appeared to be a fixed ghost image in the background (odd lines in the image) with the live picture (even lines) superimposed on that.. does this sound similar? Ben
