1. This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.

Capture problems only with some 8mm tapes - Any Ideas?

Discussion in 'Video capturing from analog sources' started by brownmaxx, Jul 16, 2003.

  1. brownmaxx

    brownmaxx Member

    Joined:
    Jul 16, 2003
    Messages:
    1
    Likes Received:
    0
    Trophy Points:
    11
    Hi all. I have seen some similar issues to mine mentioned before on these forums but I have yet to find the solution. Maybe someone here can help....

    I am currently involved in a project of capturing home movies to my PC and transferring them to DVD. These are mainly on 8mm tapes (with some older ones on VHS). My system specs are below.

    Most of my captures look great, but there are a few tapes I have come across that cause a video problem. Although they play perfectly well on the camcorder LCD, and look fine when viewed from the camcorder on my tv, when fed in to the PC the picture gets some kind of "effect". Let me try to describe it....

    The picture looks shaky and scrambled with messed-up colors but only at the top portion of the screen (varies, sometimes it is the top 20% of the screen, sometimes the top 50%, but never towards the bottom). This looks very similar to what you might see with either a scrambled cable channel or with Macrovision, but again it is only towards the top of the screen (and of course these are home movies taken on an 8mm camcorder, so there is no Macrovision on these tapes!).

    I have now set up my camcorder so that I can view these tapes on my TV and PC at the same time. The effect is there on the PC (even when just viewing and not capturing) but not on the TV.

    All settings on the PC side are the same for these few tapes that cause this effect as for all the other tapes that do not. When I look at the captured video frame by frame I can see that some frames look perfect while others have this "distortion" effect. I can post a URL to some sample images and/or short video clips if it is helpful to understanding what I am describing.

    Anyone have any idea what could be going on with these tapes and what I can do to correct it? BTW, I seem to have the same results no matter what resolution I use for capture.

    Thanks all,
    Michael (brownmaxx)

    System Specs:
    Abit IT7 M'board
    P4 2.2GHz
    1GB DDR SDRAM
    (4) Maxtor 80GB ATA133 7200RPM Drives
    ATI AIW 8500DV
    Windows 2000 Pro
     
  2. jnihil

    jnihil Moderator Staff Member

    Joined:
    Dec 23, 2001
    Messages:
    869
    Likes Received:
    0
    Trophy Points:
    26
    Perhaps a video stablizer might help. This is what I found on dvdrhelp.com. Seem you're not the only one:

    "Capturing Hi8mm analog to AVI or MPEG2 works great. Capturing VHS tapes made within past few years works great too.

    But a major flaw has to do with old tapes. Say those recorded over 5-10 years ago. Not commercial tapes, but home videos recorded in the 80's.

    Flaw is that when playing these tapes on current generation VCR's such as Sony, JVC, (4 head, digital tracking etc), they look great on TV. But when seeing video on PC even in capture preview, there are occasional frames of distortion on top 25% of video. Can be best described as tearing or bending of the top of the video.

    Have found that by finding an old 2-head vcr from 1980's problem doesn't exist. Has something to do with AGC circuitry in current VCR's not present over 10 years ago. capture card appears to not handle this correctly. Via web/google searches have found dozens of other 8500DV owners with same complaint. Exchanged emails with a few. Even sent ATI customer support lists of complaints from others, sample pictures and they haven't responded with anything other than "will get back to you" in a month. Talked to them by phone too."


     
    Last edited: Aug 2, 2003
  3. alla

    alla Guest

    Look for this macrovision remover.
    It will help you

    ** edited by moderator. Follow the forum rules **
     
    Last edited by a moderator: Aug 2, 2003
  4. luigi2000

    luigi2000 Member

    Joined:
    Nov 26, 2002
    Messages:
    9
    Likes Received:
    0
    Trophy Points:
    11
    The distortion described is caused by a different amount of tape tension applied to the tape during playback than tension applied during the recording. Also as video tapes age the elasticity can change resulting in this same distortion. This is called skewing. The skew error is observed at the video head switch point just before the vertical blanking interval. As skew error increases the picture will flag. This is not a timebase error. The Horizontal Auomatic Frequency Control (HAFC) time constant circutry in television sets are springy by design to compensate for timing skews. Find another tape player that might playback the tapes with less skew error. Or find a technician to adjust the tape ten$ion.

    Bona fortuna.
     
  5. Tensor

    Tensor Guest

    I am currently involved with the same project, with a slightly different problem.

    I recently found a cache of tapes stored horizontally, and during playback, there is no sound played just video.
    Is this the same type of problem?
     
  6. savoy

    savoy Guest

    Try a very simple solution (and one I had to use for the same reason): put a head cleaner cassette into the 8mm camera/vcr and run it for 15 seconds. The older tapes probably stick or release metal particles onto the read heads. It solved my problem.

    Now, I have a different, but creative problem, in trying to capture only the audio from these captured tapes (on my HD now) so I can use them as overlay on new scenes. Any suggestions?
     
  7. luigi2000

    luigi2000 Member

    Joined:
    Nov 26, 2002
    Messages:
    9
    Likes Received:
    0
    Trophy Points:
    11
    Assume Tensor's audio circuitry can capture if the analog audio signal is present, but only captures silence.

    A cause of bad audio record/playback is worn pinch roller. Worn pinch roller is a major cause of edge damage to video tape. Also a tape with a loosely wound pack stored horizontally can cause damage. The audio signal is recorded next to the bottom edge of the tape. A machine with a misaligned tape path can also cause edge damage. Edge damage will keep the tape from passing smoothly over the record/play audio heads. This results in a bad audio recording or playback depending when the damage occurred. Inspect the bottom edge of the tape by lifting the door of the cassette. The bottom edge of the tape will be wrinkled. Generally the audio signal will not be recoverable when the edge is damaged. If the signal is valuable, then a savey technician can very carefully apply constant and even pressure to the back of the edge of the tape during playback to recover the audio signal.

    Another cause of bad audio is dirty or clogged audio heads. Cleaning with a lint free cloth soaked with freon or isopropyl alcohol can restore the playback signal.

    Bona fortuna.
     
  8. ronowens

    ronowens Member

    Joined:
    Feb 7, 2004
    Messages:
    3
    Likes Received:
    0
    Trophy Points:
    11
    I am trying to capture/convert the family archives from 8mm to DVD, when capturing from any device there is a "squiggly" lone along the mottom of the screen. This does not show up when the image is playe on a TV. It looks like a tracking issue. Is there anyone else who has dealt with this and found a solution. Also, the audio quality is not very good during capture. These tapes playback fine on several differnt camcorders I have tried so I do not think that it is the tape, but something in the capture process.
     
  9. beammeup

    beammeup Member

    Joined:
    Jun 11, 2013
    Messages:
    6
    Likes Received:
    0
    Trophy Points:
    11
    Hi,

    I currently have the same " blurry lines at the bottom
    of the screen " whilst capturing from VHS.

    The TV monitor doesn't show it at all, but my PC screen does.

    If it not to far up the screen, you could just try cropping the bottom 5 or 6 pixels out of the final rendered file???

    It works for me
     
  10. beammeup

    beammeup Member

    Joined:
    Jun 11, 2013
    Messages:
    6
    Likes Received:
    0
    Trophy Points:
    11
    Hi,

    I currently have the same " blurry lines at the bottom
    of the screen " whilst capturing from VHS.

    The TV monitor doesn't show it at all, but my PC screen does.

    If it not to far up the screen, you could just try cropping the bottom 5 or 6 pixels out of the final rendered file???

    It works for me
     
  11. ronowens

    ronowens Member

    Joined:
    Feb 7, 2004
    Messages:
    3
    Likes Received:
    0
    Trophy Points:
    11
    Thanks for the advice. How do you crop? We are using Premier and just getting started with it. I would also like to know what causes this if anyone has delved into it.
     
  12. taclark

    taclark Guest

    I stressed out over these squiggly lines as well. . .until I recently read that it's called NTSC crawl and that its normally okay, i.e. I don't need to worry about it (no cropping or change in capture setting). So I stopped trying to eliminate it and found that on my final product (DVD), it doesn't show up.
     
  13. ronowens

    ronowens Member

    Joined:
    Feb 7, 2004
    Messages:
    3
    Likes Received:
    0
    Trophy Points:
    11
    Thanks, I will try to do a complete project and see how it comes out.
     

Share This Page