Do you actually mean lines, not "pixel-lines"? I know the the grabber grabs a 768x576 bitmap from a PAL signal, but that has nothing to do with lines. I'm talking about the quality of the captured signal. It's a question about analog-to-digital conversion. It's like good optic or bad optic. If you have a digital camera with 2.2 mill pixels and one with 3.2 mill pixels, then the second isn't neccesary better than the first. It depends on the optic and the quality og the analog-to-digital conversion. Therefore different videosystems have different number of lines as a measure of quality.
There must be some difference in the quality on different framegrabbers. I think there must be framegrabbers that makes better pictures than my Pinnacle PC TV on the same PAL input? Which chipset has the best analog-to-digital conversion?
Does anyone have a comment on this? Are there some video-production pepople on this list?
Thanks
- Martin O.
David Balazic wrote:
Martin Osmundsvåg wrote:Hi! Sorry to bother you all, but I can't find good information about these topics. I'm wondering if there is a framegrabber for linux capable of resolutions as good as commercial DVR-systems? I have looked into resolutions on different systems for PAL signal. VHS= ca 300 lines, SVHS= ca 400 lines, DV= ca 510 lines and a Sanyo DVR= ca 530 lines. What about the v4l framegrabbers? What chipset gives the best resolution? Another topic: Is it possible for a framegrabber to capture both fields seperately? Many of the DVR has an option to record in 25 frames or 50 fields. Then you can have fast object moving without the "echo"from the last field I get when grabbing with my Pinnacle PC TV (bttv-driver). What chipset/framegrabber could give me 530 lines of resolutions (or the best result)? Suggestions and comments would be most appreciated.The PAL video signal always has 625 lines, about 576 of them actually being a part of the picture. bt848/bt878 chips return all of this lines ( 576 is no problem, I am not sure for higher number of lines ).
