View Full Version : Efficient capture of 8mm & Hi8 via Digital8
bonaparte_o_looneasa
15th May 2006, 06:21
I have an archive of 8mm and Hi8 tapes that I wish to digitise for storage and editing on disk.
I can do this via analogue capture or by using a Sony Digital8 camera.
The large number of tapes makes the Digital8 method attractive since it captures in one step. However I get an AVI file using the DV codec, at the usual 13GB per hour. I assume that this is wasting space, since analogue tapes do not contain as much data as miniDV.
Q: Is there another approach that will capture the analogue tapes at a lower GB/hour rate without loss of quality ? Since this is an archive I would prefer only mainstream (ie likely to be supported in the long term) solutions.
TIA.
jggimi
15th May 2006, 13:53
Hello, and welcome to the forum.Is there another approach that will capture the analogue tapes at a lower GB/hour rate without loss of quality ? The short answer is: No. Here's a slightly longer answer:
All MPEG compression is LOSSY. This includes MPEG-1, MPEG-2, or any of the many MPEG-4 codecs.
DV is also lossy, though the loss is significantly less.
The "best practice" for analog capture is to use a LOSSLESS codec when capturing (see our analog capture guide and FAQ), which consumes more disk space than DV. However, this is not for archive, but for editing, filtering, and compression to a final lossy format.
DV "storage" is usually to tape. Be warned that magnetic tapes are not of archival quality, and this is best used as a short term medium rather than archival.
We have a forum dedicated to DV which you may find helpful.
laserfan
15th May 2006, 14:58
I have an archive of 8mm and Hi8 tapes that I wish to digitise for storage and editing on disk...I have done this and believe the following:
1. To transfer via Firewire from my D8 camcorder is to retain all the quality of the origina 8 or D8 recording. I use WinDV for this and cap as Type2 avi.
2. Once capped, I have numerous options to edit, convert, re-compress, filter etc. though yes the files from the D8 camcorder are very, very large.
3. When done, my new version(s) whether set-top DVD compliant or Xvid are burnable to DVD, but I still keep the original tapes.
As much as has been said about the questionable longevity of the magnetic tape medium, in my experience writeable DVDs can actually be LESS reliable! For precious videos e.g. family home movies I would make at least two DVDs of everything.
jggimi
15th May 2006, 17:53
1. To transfer via Firewire from my D8 camcorder is to retain all the quality of the origina 8 or D8 recording. You may believe it. You can get a very acceptable level of percieved quality, and this method may be fine. But *all* the information, therefore all the possible quality, isn't there. First, as I stated above, DV uses lossy compression. There is detail loss. Secondly, DV uses a limited colorspace, which also causes loss.
laserfan
15th May 2006, 18:08
You may believe it. You can get a very acceptable level of percieved quality, and this method may be fine. But *all* the information, therefore all the possible quality, isn't there. First, as I stated above, DV uses lossy compression. There is detail loss. Secondly, DV uses a limited colorspace, which also causes loss.Well, I guess you have more faith in the analog capture process than I do--there is going to be loss outputting from the camcorder's analog outputs, and inputting to whatever gizmo the OP uses to convert this analog signal to digital.
Now I will admit, I thought that the signal on the digital tape was DV--you are saying the conversion to DV only occurs upon playback & xmission thru the firewire?
I realize this ? is somewhat OT, as the OP is talking about analog tapes, not digital...
jggimi
15th May 2006, 20:16
Don't misunderstand me, we may be both esoteric and OT -- but I was talking to using a DV device as the analog capture device.
Yes, if the source is a DV tape, then a DV "capture" via firewire is just a digital file copy, hence the "best" you'll get from a DV device.
If the input is analog video, as the OP described, then converting to digital via an A-D converter and capture card allows for a possibly better digital video file on disk, that's all.
Using a DV cam as the capture device (with its own A-D converter) while not the best possible, may still be perfectly acceptable. I've captured with both PCI capture card and DV cam, and for many purposes, and many sources, the DV cam is more-than-good-enough. :)
laserfan
15th May 2006, 22:01
I agree w/everything you said jggimi. I guess to the OP I would say as jggimi did "there is some loss of quality no matter which route you choose".
I in fact have both a Digital8 camera (that I've captured old 8 & Hi8 tapes thru) a decent MPEG2 capture card (a Canopus MVR1000), and analog PC capture card, and I tend to like the D8 playback/firewire capture method myself--you play the tape and it's on your computer and you can have at it. But honestly I've chosen that method because for me it seems easiest.
In any case converting home movies made w/8mm videotape, especially when you've ripped commercial DVDs or capped HDTV as I have, is a little like trying to make a silk purse out of a sow's ear! I wish there was a "magic bullet" for these old recordings but alas there is none. ;) :p
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