... and TBC are expensive :( So, I can't encode those videos :( Thank you for the answer!
Does someone have any idea to solve this? :) On 8/23/11, Roger Dahl <[email protected]> wrote: > On 2011-08-23 08:56, asbesto molesto wrote: >>> I probably won''t be able to help you, but when you try to capture the >>> same section of tape multiple times, are the same frames lost each time >>> and does it freeze in the same place each time? >> It seem to freeze almost in the same place, but sometimes the result >> is better, sometime not :( >> >>> Do the frames that you are able to capture before and after the problem >>> areas look ok? Do they have any kind of horizontal sync problems at the >>> top, move vertically or have interlacing issues? Do the colors and >>> brightness look ok? >> Colors and pictures seem OK but when I play the stream directly >> (mplayer /dev/video0) i notice some weird lines at the bottom of the >> image; I made a screenshot, it's here: >> >> http://zaverio.com/~asbesto/capture1.jpg >> >> (p.s. that image was just me kidding many years ago :D hahahahahahah!!!) >> >> What are those lines and what they mean? >> >> ps everything here is PAL > > Old CRT TVs used magnetic fields to guide an electron beam across the > screen. At the end of each field, they needed time for resetting the > magnetic fields back to the beginning, upper left, screen position. That > period is called the vblank. Anything in the video signal that was > output to the TV in this period would be invisible. In addition, they > used a technique called overscan to hide issues with their power > supplies, further hiding signals output to the TV while the electron > beam was in the overscan areas. VCRs often (always?) output junk during > these times, probably related to the way the video heads scan the tape. > > I have two cards, a PVR 250 and an HVR 1600. In my experience, both of > these cards are easily confused by junk in the video signals during the > vblank and overscan. It's just bad engineering because LCD TVs have no > trouble at all with the signals. Issues I'm seeing are poor hsync at the > top of the screen, misinterpreted odd/even field signals and poor colors. > > My guess is that the tapes you're having trouble with were recorded in > some way that is causing the VCR to output junk during the vblank and/or > overscan periods that cause the card to lose track of the vsync signal > in the video. > > I think that a TBC, Time Base Corrector, would fix your issues. It sits > between your VCR and your card and cleans up the video signal. Just for > fun, you could try re-recording your tape onto another tape. That could > fix up the problems, at the cost of worse quality. If you have a DV > camera, you could try recording onto the DV camera and dump the digital > data out via FireWire. Another option is to just send the tapes off to a > company that has professional equipment to do transfers to digital, > though I would not recommend that if there are any beheadings on your > tapes :) > > Roger > > > _______________________________________________ > ivtv-users mailing list > [email protected] > http://ivtvdriver.org/mailman/listinfo/ivtv-users > -- 73 de IW9HGS - Gabriele "Asbesto Molesto" Zaverio Museo dell'Informatica funzionante - Freaknet Computer Museum http://museum.freaknet.org || http://freaknet.org/asbesto GPG Fingerprint: 8935 5586 7F2D 9C5E 51B6 BBC5 EA15 9A4E 613D 44D7 _______________________________________________ ivtv-users mailing list [email protected] http://ivtvdriver.org/mailman/listinfo/ivtv-users
