Archived from groups: rec.video.desktop (
More info?)
wthack@aol.com wrote:
>I made my first DVD and when doing an A/B compare to the source VHS I
>am very disappointed with the degradation in both video and audio
>quality. The video lacks sharpness and saturation and the audio seems
>to saturate when compared to the 20 year old VHS tape.
>
>I am moving old VHS home movies thru a Canon ZR70 camcorder using it as
>an AV to DV converter. The DV stream is being sent to my Dell over a
>Fireware port. The video is captured as a .avi file using Sonic MyDVD.
>I use Microsoft MovieMaker to do any editing and save the file as a
>.avi again, and then I use Sonic again to burn to DVD.
NOTE: you are staying DV throughout the editing process aren't you?
Then transcoding directly from DV-AVI to MPG2.
>
>Where in this chain am I losing my fidelity? What is a resonable
>expectation for video/audio quality in a DVD made from a VHS tape?
Hi,
There are a number of places where a source tape and the resulting DVD
can vary. It might be in the coding, which others have suggested, but
that is the least likely place unless you are trying to cram a lot of
material onto a DVD. (In other words, if you are trying to put six
hours of VHS onto one DVD you are going to have to do a lot of
tweaking to get reasonable results.) You can get one or two hours on
a DVD pretty easily, but more than that can really take a lot of
effort.
Probably what is happening is that when you run your VHS output
through the SR70, it is expecting the video to have standard DV
saturation levels. However, VHS saturation is standardized at about
1/3rd the DV level, therefore, you end up with really washed out
color. To make matters worse, hue, brightness and contrast are all
different on VHS than on DV.
Another big source of trouble is that your Camcorder is really
expecting to get the color signal through it's S-Video input, and you
are probably sending the signal composite. Your TV can do a great job
of handling a composite signal from VHS, but converting to DV/DVD from
composite can lead to the loss of much of the color information.
The next loss of saturation occurs when converting the 4:1:1 DV signal
to the 4:2:0 MPG2 for DVD. If you started out with a low saturation,
it is only going to suffer in the conversion.
The easiest way to fix this difference is to use something like a Sima
Color corrector to boost the saturation, sharpness, brightness and
contrast of the VHS signal before it is encoded by your SR70 and
recorded to an AVI file. What you would want to do is capture short
(5 min?) segments at different settings and run them through your
editing setup until you get the best settings.
Your sound problems appear to be over modulation. You may have to
reduce the volume of the audio stream before it is captured. Unlike
analog recording which has a lot of spare overhead, digital recording
has essentially no safe overhead at all. The moment you move past the
maximum volume level, you immediately get massive distortion. Also,
VHS tape is normalized at -3Db, while DVDs are normalized at -20Db,
so, unless your editing software is properly set up, you are likely to
be recording your sound levels much to loud on the DVD. Also, make
sure you are recording from the "HiFi" track, if your VHS is HiFi.
There are many places that problems can come in when converting analog
video (VHS) to DV or DVDs. You have to work through your system and
see what is going wrong. One of the biggest problems can come from
expecting to have a soft 6 hr. VHS tape look great on a DVD,
especially on a new higher quality TV. What you discover is that you
don't notice how bad your VHS recordings looked until you get them all
sharp and crisp, then you discover that they really look like hell.
Hope this helps,
Susan
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