Archived from groups: rec.video.desktop (
More info?)
"Richard Ragon" <bsema04NOSPAM@hanaho.com> wrote in message
news:QwURc.21401820$Id.3542684@news.easynews.com...
> kmc wrote:
>
> > I'm interested in converting my hi-8 tapes to digital for archiving
> > and eventual editing.
> >
> > I've read that the Canopus AVDC 100 or 300 are good units for
> > accomplishing this taak. Another method is to use a digital camcorders
> > that has an analog to digital pass-through. Apparently this allows you
> > to connect an analog source and use the digital camcorder's circuitry
> > to make the analog to digital conversion.
>
> Yep. You can't go wrong with a AVDC-100. I have a 300, and it also
> works with the Mac and PC too.
>
> > If you you've done either method, or even better, both methods, can
> > you comment on which would yield the best picture quality. And if you
> > feel one way is better, can you tell me what the pros and cons are of
> > one method over the other.
>
> Both do essentially the exact same thing. But the 300 is more for
> correcting bad VHS tape masters. Since you have a Hi-8, I'm going to
> assume that the tape quality (because its still fairly new) is still
> good. I'd stick with the 100.
>
> Also.. another alternative would be to "buy" a newer Digitl8 camcorder.
> D8 has the ability to play those Hi-8 tape, while making new tapes in
> Digital format (using the very same tapes), and it also has a Firewire
> port giving you access to digitize the video from the camera and avoid
> using a bridge like the AVDC-100.
>
I essentially agree with you, except perhaps the ADVC-300 noise reduction
is more helpful than was implied. Firstly, it can provide NR BEFORE the
digital encoding, which is VERY HELPFUL even for DV25.
The analog tape formats (e.g. VHS, SVHS, 8mm and Hi8) have noise that isn't
very visible, but does create some challenge for the DV25 encoder (and also
for any subsequent MPEG encoder.) You really want to do NR before DV25
encoding because DV25 isn't very friendly to signals with random
characteristics.
MPEG is even worse, but you can do some NR to a previously DV25 encoded
signal, but a 'challenged' DV25 encoding will already be damaged.
Note that I am being somewhat 'purist', but in some cases, the absolutely
best
quality is desired. Some of my discussion is relative to LD (and composite
video), but my claims are still mostly valid for SVHS/Hi-8 (just recognizing
that the 3D comb is only one of the improvements in the ADVC-300...)
The NR action provided by the ADVC-300 is also helpful for LD, and the
3D comb in the ADVC-300 is very very good. The TBC action of the
ADVC-300 is more than adequate for LD also (of course, works well with
tape formats also.)
When using the ADVC-300, and comparing the results with D9 (DV50), it
might be plausible that one half of the quality difference between normal
DV25 and DV50 is bridged by using the very high quality ADVC-300. When
I do the very best signal processing that I can do with my DV50 system
(grabbing
a LD, but still applicable to Hi8), I can obtain higher quality than any
DV25
combination of my system. The ADVC-300 bridges enough of the quality
difference
that the advantage of using DV50 with LD or any consumer tape format is
mitigated. The probable reason for the quality improvement is that the NR
and
excellent comb filtering (for LD) provided by the ADVC-300 allows the DV25
encoding to do the best job possible (alot of the randomness of the signal
is
removed, and PROBABLY allows for use of more coefficients for the actual
video and not wastefully encoding the noise.)
So, for normal video, the ADVC-300 does a fantastic job, and pushes DV25 up
to
the level where DV50 is less justified in at least one of my applications.
On
the other hand, DV50 does MUCH better when the signal has alot of
randomness,
and you wish that the randomness is very accurately reproduced. This would
mean
that the DV50 is justified when signal processing (NR) is deferred until
later. (This
is slightly off topic, but I am trying to give as much background as
possible.)
When using the ADVC-300, one should be very careful about avoiding TOO MUCH
processing. I have found that the minimal settings for each major feature
is the
wisest course. For very noisy signals, where quality is already severely
compromised,
then perhaps nudging up some of the noise reduction might be useful.
However, with
pristine source material by LD standards (it is still a little noisy and
normally would have
comb filter artifacts crawling around with non-3D decoders), the lowest
settings help
to provide damned good video quality for my eventual MPEG2 SDTV DVDs.
When I want to produce the absolutely highest quality DVD from an ancient
LD, I might
do an initial edit on DV50 (not necessary in your case), but equivalently,
the LD might
be grabbed by the ADVC-300 (perhaps with an essentially redundant DPS290 TBC
before
the ADVC-300, but I suspect that there might actually be a loss of quality
given the very
supurb ADVC-300, except for damaged LDs that the DPS290 actually helps to
recover.)
For the LD, the lowest settings for NR, comb, etc are adequate. Edge
enhancement should
mostly be avoided.
After grabbing onto DV25, then edit on DV25. Avoid encode/decode cycles,
because the
quality of the ADVC-300 results are so darned good. Then, I use the most
aggressive NR with
TMPGENC -- as long as motion artifacts don't appear. When I replay the
results of an old,
discontinued LD that had been copied onto DVD, the video is so good that it
never really looks
like it was an LD. AFAIR (I haven't checked recently), much of the time, it
might be difficult
to determine if the video was ever composite, and the biggest, semi-obvious
defect would have
been a little softness.
For SVHS and Hi8 (instead of LD), you'll essentially max out the quality,
and actually do better
than an analog to DV25 converter without NR. Those extra DV25 coefficients
really do help the
picture quality. The challenge to see the 'difference' can be difficult
because the DCT
is a transform that is purposefully more difficult to see when coefficients
are dropped because
of compression.
Frankly, when I use the ADVC-300, it sometimes tricks me into forgetting
that DV25 is
being used in the signal path. It would be a stretch to claim that the
ADVC-300 overcomes
the deficiencies of the DV25 relative to the DV50 format, but the improvment
is substantial.
John
Facebook
Twitter
Instagram