Virtualdub and VHS Tapes - Capturing
and Encoding techniques
UT CK
Senior Member
posts: 51
(1/19/01 3:57:27 pm)
Reply Some basic background on Video Capturing.
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I want to thank Doom9 for demonstrating flexibility and extending the
forum with this topic.
And so begins the process of sharing and learning.....
I own an extensive library of VHS titles which are in great quality. I
want to preserve my VHS library and "digitize" it to CD's. The growing
pains have been difficult, but I am very satisfied with the results. If
you can offer suggestions for improvements, I would be grateful.
Digitizing rationale:
VHS tapes have a tendency to deteriorate due to many factors. VHS can
degrade by being played; it loses it's coating while rubbing on the VCR
mechanisms (ie: rubber, heads, etc....). The tape can also stretch as a
result of being accelerated and decelerated (rewind, pause, fast forward).
And finally, the environment in which you store VHS tapes can have adverse
effects on it's physical attributes; storing in a dry environment will
make the VHS tape more brittle and subject to breakage, too much humidity
and it will damage as well as cause VCR problems.
Quality factor:
A VHS tape which has been properly digitized can be quite visually
pleasing. I won't even try to compare it to DVD quality, this is not my
objective. I will say however that if my results look good on my PC
screen, I will undoubtedly be very pleased with the results on TV. My
objective is to try to digitize my analogue tapes while retaining as much
original quality as permits. Many enthusiasts have keepsakes on VHS, this
is a way of preserving history.
PC Capture factors:
Digitizing a tape, is better known as "Video Capturing" (ie: the process
of taking the analogue media and converting it into bits and bytes. The
factors which affect this process are a combination of hardware and
software conditions. Almost invariably, having a hardware device which is
dedicated to "Capture" will produce more desireable results. The reason
for that is that the equipment carries onboard circuitry whose sole
purpose in life is to do just that(ie: encode and decode). The CPU
interacts with this equipment, but plays a secondary role. On the rise,
are products which combine video capture capabilities with gaming and/or
graphical specializations, these video cards are called hybrid or "all in
one" cards. These hybrid cards are very popular, but they are not the
solution for videophiles with a passion for capture, they are for the
hobbyist who wants to do many things while sacrificing some aspect of the
functions. You will have to do research to come up with the solution best
suited for your needs.
Another important aspect of capturing video to PC, is the amount of space
you can reserve for the process. Also, the speed of your storage device
(hd) should ideally be 7200 RPM. The new IDE ATA66 capable drives are
ideal for this application. For the serious hobbyist, I would suggest a
minimum of 30 GB of disk space, dedicated to your captures. Capture
success is also dependent on the resolution you select and the CPU power
that you have at your disposition, if you opted for the hybrid solution,
you will require more CPU power to compensate for the lack of a dedicated
hardware capture device.
Economical factors:
Why on earth would someone want to "digitize" their VHS library ?
(economically speaking)..
To all those people who bought a capture card, you did it because you
wanted to take analogue information and convert it to digital. Converting
DVD's to CD's does not require a capture card, it requires a PC DVD player
and a lot of knowledge (to be good at it). So you spent money on that card
and now you want to get benefits from it. If you're like me, you have many
VHS tapes which you consider to be "quite nice to watch". You also know
that playing them takes it's toll on the quality. You would like to go out
and replace them all with DVD's. You already spent good money on your VHS
collection and you would prefer to keep your money for buying new DVD
titles that you haven't seen. What's the solution ? Well, mine is to spend
$2 on 2 Cd's , capture my VHS tape to disk and then burn that onto 2 CD's.
When I've completed that, I can (if I want to), selll my VHS tape for
about $4 (they're all good titles). But being who we are and given the
fact that we are enthusiasts, we will keep them and let them deteriorate
on the shelf until they break in our VCR's (if we still have one, after it
breaks). I know one thing.... I won't go out and buy another VCR, so what
would I do with all these VHS tapes after that ? Hmmm maybe my mom is
looking for some movies to watch..... { : (B)
To summarize, it makes good sense to convert your VHS library now, before
you are faced with an unwelcome situation. Converting my VHS library to
CD, will take me 6 months at 1 per night, it will cost me $2 per
conversion, that's a total of roughly $400 CDN. If I decide to replace
them all with DVD's it will cost me $4000. Have I demonstrated a viable
application for the harware you purchased ?
I look forward to sharing my experiences and learning from yours.... I
intend to post here regularly. I will be posting my capture process in the
very near future and invite you to critique it and help me improve on this
challenging quest.
Regards,
CK
Coca Lola
Registered User
posts: 5
(1/20/01 2:02:30 pm)
Reply Filters
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I have been playing around a bit with the VirtualDub filters and I believe
that they are very useful.
I use this setup:
VHS -> DC10+ via composite cable
M-JPEG compression, framesize at about 59K
at full resolution 720*540 using VirtualDub capture
using driver brightness setting a bit higher than
default
VirtualDub Filters:
TV filter 5x5 chrominance average
Level correction filter, I cut away the lowest and
highest levels in the video. Using the scan video
function a can get a good estimate of where
the video's real levels are. (The levels I cut away
are the unused ones, so the video will use the full
frequency range)
Smoother, smoothing away the noise will increase
the encoding quality considerably. I sometimes use
the noise prefilter in the filter howewer I find that it
will remove detail incorrectly because it can treat
fine detail as noise. So it depends on how bad the input
is. A low filter setting is hardly noticable, because the
filter doesn't touch the edges in the video.
Frameserve via VirtualDub's experimental VCM mode
to WM8 at around 700 - 780K, 48 or 64 Kbps audio. VBR2
Do you know of any place where I can get more filters?
Coca Lola
Registered User
posts: 8
(1/23/01 12:45:03 pm)
Reply Re: Later in the week
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About 10 GB for two hours of video I would say.
It the depends on the quality setting for the compression
codec. I use about 59K per frame which is a compression
ration of about 19:1.
chemmajik
Registered User
posts: 6
(1/23/01 1:35:53 pm)
Reply Re: Some basic background on Video Capturing.
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Since I do alot of 720x480 captures, I will say this, my cel366at550 cas2
ram(bh6) I have to usually make my audio of less quality to prevent
dropped frames. Since I'm using a vcr its really a waste anyways of using
stereo, since its a mono anyways. I've been satisfied with 44Khz 8bit for
most movies, then recompress with mp3 radium pro 64k. Also I'm using a
sblive value. I've found m4c is the way to go, I just consider wm8 just to
much a hassle, and its really not much faster then m4c. I'll pass until it
has gotten out of beta, now if someone could convert m4c into pure
assembly mpeg4 codec. Also after looking at opendivx, it has a year to go,
bec it hardly uses assembly.
okami111
Junior Member
posts: 13
(1/26/01 2:58:37 pm)
Reply VD filters list
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stuwww.kub.nl/~s527912/
(dynamic noise reduction,static noise reduction...)
home.bip.net/gunnart/video/
(deinterlace pal movie,deinterlace are based...)
flaxen.dynip.com/vdf/
Especially the fxVHS filter!!
Regards,
-----
Okami
http://www.flexion.org/team/okami
Albertw2
Please register!
(1/27/01 3:20:11 am)
Reply Why VCD better than VHS?
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I have read different articles stating that you should
copy your VHS tapes every seven years. Ok, they do degrade, but that fast?
Also writeable CD's do to.
What re-recording interval would be recommended for the
CD's? Would it depend on the maker of the CD-R or
CD-RW?
Kodak, Maxell, Acer, Verbatim.
I have read CD-RW should last 30 years? Is that all?
Al
UT CK
Senior Member
posts: 91
(1/27/01 9:03:17 pm)
Reply Re: Why VCD better than VHS?
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On copying your VHs after 7 years... You will get yourself another 7
years, but you will lose quality during the transfer and you will be
copying a VHS which has degraded significantly to begin with. Your
original will be poor.
Copying your CD later, you will lose 0% quality since it's digital.
I've done some reasearch on that subject and there is a basic formula that
will give you an approximate idea of the longetivity of various CD
recordable media.
Unrecorded media:
On average the shelf life of any UNRECORDED CD recordables is roughly 6
years. The unrecorded media is subject to being "corrupted" by light
seeping in , hence burning the media prematurely and rendering it useless.
(it can be used as a coaster for your drinks). Ideally you would want to
store the unrecorded media in a dark room, with comfortable levels of
humidity. Roughly 45 % humidity.
Once recorded:
The "green" / "blue" coloured CD's (recording surface) are generally made
from a cyanide based dye. They are cheaper to manufacturer but are subject
to break down "chemichally" much faster than the "silver" or "gold". They
last around 15 to 20 years on average. Again store any CD in a dimly lit
area and they will last longer.
The "silver" coloured CD's are the "working class" and most popular "good
grade" recordable Cd's. They last about 50 years before they break down.
The "silver/gold" hybrid Cd's last about 75 years.
The "Gold" Cd's last about 100 years. ( These are all estimates).
The manufacturers of Cd recordable media are always experimenting with
cost versus quality. Kodak is the company to closely monitor. Their CD's
are a way to measure the cost vs quality of recordable CD's. Kodak started
out making striclty GOLD CD's , then they tried a mixture of "green/blue".
They quickly abandoned the "green/blue" because they discovered the
savings did not justify the degradation in quality. Most "kodak" customers
store their keepsakes on CD's in the form of Photographs and Video.
Kodak's reputation could not be compromised to the extent of trying to
compete with the "green/blue" market. Kodak opted for quality and
longetivity for the reasons I mentionned. Today, Kodak is selling a hybrid
"Gold/Silver" InfoGuard for roughly 1.49 (CDN) and the pure "Gold" for
1.99 (CDN).
Regards,
CK
{ : (B)
