VHS Capture Problem

[sgbeattie]

Hiya Forum Guys,

I use a YUAN FUNTV Capture Card.

I capture directly from VHS and
while the quality is quite good,
there is a noticable 3-4 mm of random
colours at the very bottom of ALL captured
files. I use COMPOSITE cabling.

What is this and how can I get rid of it
from future rips?

Thanks.

[JohnnyMalaria]

Hiya Forum Guys,

I use a YUAN FUNTV Capture Card.

I capture directly from VHS and
while the quality is quite good,
there is a noticable 3-4 mm of random
colours at the very bottom of ALL captured
files. I use COMPOSITE cabling.

What is this and how can I get rid of it
from future rips?

Thanks.

It's the so-called "head switching noise" that is always present on consumer analog video. Normally you don't see it because of the overscanning employed by consumer TVs.

If you intend to create DVDs for viewing on TV, don't worry about it.

If you intend to create DVDs or other formats for viewing on a PC, you'll need to either crop the video or place a black bar over the offending noise.

Head switching There are two write heads mounted on the video head assembly. The write heads are mounted 180 degrees apart. The videotape is wound on the head drum at slightly more than 180 degrees. This allows for a slight overlap in information between the heads. The video head rotates under the tape so that the tape travels at one speed and the video head travels underneath at a much higher speed. The tracks are scanned alternately by the "A" head and the "B" head. Each track corresponds to one field of the interlaced video signal.

During the playback of the tape, the video heads are timed to avoid double playing the redundant region. The video head switching pulse falls in the "blacker than black" area below the bottom of the television. However, it can be seen by adjusting the vertical hold control so that the vertical sync pulse moves into the viewing area. Any picture disturbance during the head switch over should be hidden by the vertical over-scanning on a TV or monitor. The head drum and capston drive form a very precise control system known as a servo. Poor servo tension can cause a large switching error that is visible in the picture.