Snell & Wilcox TBS24 for VHS to digital transfers ?
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To swipe a quote from a Creative Cow user post: Quote:
This Snell & Willcox, for example, appears to be a TBC + proc amp. You're correct, I don't have specifics on this particular model, nor first-hand experience with its use. But I do have some general observations about rackmounted TBCs. These were built for non-VHS analog workflows that pre-date digital conversion work. As such, most of them make for poor additions to your VCR + capture card. At worst, this may turn out to be a great proc amp, and it has that added noise reduction. It may be because of the simple reason given in the above quote: a base TBC can correct a signal, but it cannot "frame sync" (not the same as genlock). Modern TBCs, designed during and for the digital conversion era, were made by companies like DataVideo and Cypress. These are essentially a version of TBC + frame synchronizer, to provide a steady and stable stream of video data to the capture card or DVD recorder. Without a stable/continuous signal, the capture session will barf itself and halt. The one issue with these is they appear to do nothing for horizontal jitter, unlike line TBCs in higher-end VCRs. I don't think the Leitch SPG-130N is a frame sync, but rather a genlock. That's of no use to you. The reason these rack mounted TBCs tend to have "good prices" is because nobody wants them anymore -- they're next to useless for consumers and hobbyists, as well as broadcasters (and even colleges) that moved up to all-digital workflows. The few holdouts for such gear are transfer and post houses, when dealing for broadcast sources (Betacam, S-VHS, etc). But even then, work has dwindled, and they have all the gear they could use -- including backups and extra parts. If anybody has contrary information, please post it. Opinions are also welcome, be it in agreement or in dissent. All discussion is welcome. Thanks. [:)] You may also find this article/post useful: What is a TBC? Time Base Correction for Videotapes I wrote that a couple of years ago.
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Interesting. I thought standalone TBC's would also take care of horizontal jitter (in fact, I thought that was the main purpose of creating a new sync signal!)
I was wondering why the NovaTrol NovaMate2 TBC I had was doing worse than my SR-V10U's TBC on one of my tapes with really bad horizontal distortions. So far the AG-1980 wins in this category among my limited amount of equipment. So what I'm wondering, then, is if it's possible to use a VCR without a TBC and still use some external equipment to cure horizontal issues? For example, I think I'd like the results I get with my older 9400U if I could correct horizontal jitter. I have TBC-1000 on the way, but from the sound of it that might not do the trick... |
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Ah, Betamax. None of those floating around my house anywhere... I almost wish there were because I've never seen/used any Beta tapes or VCR's.
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It's also discussed here: What is a TBC? Time Base Correction for Videotapes I use that method, and it's quite good. One workflow is currently: Panasonic AG1980 > Panasonic ES10 > JVC DR-M10 VCR for tape transport, ES10 for jitter, DR-M10 for chroma removal (XP mode capture). After the hardware has done its work, video is further processed in Avisynth + VirtualDub, then finally Premiere CS4. (Audio has hardware/software work too, but concentrating on video for conversation.) And it does quite well. Note that our workflows are temporary, based on the project. Gear is swapped around, re-wired, etc, as needed. Nothing stays connected for very long. Most items don't even stay in the same spot on the custom racks more than a few months max. I'd be curious to see what the S&W NR controls can do, if anything of significance. |
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I've been eyeing up some ES10's, but some (I think including Lordsmurf) say that it over-processes video and even introduces artifacts when used as a pass-through? Or is that only if you actually use the ES10 as the authoring burner... |
Yeah, the ES10 is not totally transparent on passthrough. I don't notice any artifacts in light scenes, but in very dark scenes it tends to make the light parts of the picture noticeably posterized. That's my experience given my ES-10 interacting with my other equipment, YMMV.
If there was a device that can do the miracle work the ES-10 can do, but more transparently, I'm all ears :) |
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Back to TBCs. One reason why pro external units seem to be unloved is by the mid to late 90s almost all pro VTRs had one built in. Built in TBCs have the advantage of being able to directly servo lock the VTRs transport to an external genlock source (helps avoid frame dropping by TBC). The best TBCs can do the following: 1. Correct severe horizontal jitter (including flagging/curling). Rumor has it, the JVC SR-VD400US (pro version of the HM-DH40k DVHS deck) can fix curling, the Digipure circuit on this model differs from past units having 6MB frame buffer. 2. Provide dynamic noise reduction, particularly chroma noise reduction (DigiPure) 3. Provide clean continuous sync output. External genlock is nice, but not needed for DVD transfers. 4. Provide dropout compensation. This one is TOUGH to find. JVC's Digipure and the popular AVT-8710/Datavideo TBC-1000 DON'T do this. 5. Basic proc-amp controls. |
FML
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Now I'm really wishing I hadn't missed it! http://cgi.ebay.com/JVC-SR-VD400U-D-...item4157c13f03 In any case, I just picked up a Snell & Wilcox NRS30 noise reducer. It has a built-in TBC, but I'm excited to see how it stacks up against NeatVideo. In Hardware vs Software processing, hardware almost always wins. I'd love to have something like the VDub Neatvideo plugin that runs as hardware in realtime. More info on NRS30: http://home.tiscali.nl/rajduim/Video...Processing.pdf (See page 7 of PDF) EDIT: Also, I have an HM-DH40000U sitting in my living room that I was getting ready to sell. Any idea if this has that 6MB buffer circuit also, or is it just the pro version? I didn't seem to get any results from it that made it worth keeping in my obnoxiously large stack of equipment. |
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The only reason I picked this up was the price and to go through these 80+ DVHS tapes I got... one of them has to have a decent movie on it... I hope. I'm still on the lookout for a nice AG-1980 and/or Mitsu HS-HD2000U for transfers though. No rush since the big 20 tape job is finished... now to deal with that guy's stack of MiniDV tapes... |
Well then in that case, nice snag! I probably would've bid you up to $75 had I not been out somewhere with friends :p
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Okay, the unit arrived today. I came up with a good test to do right from the start. I have an EP tape that is a second-generation transfer from VHS-C to full size VHS. It has a lot of chroma noise at the beginning of the recording, I think the full-size tape was also recycled (I was 9 years old so it's hard to remember!)
I tried the Chroma Noise Reduction feature, and it had pretty good results! Picture 1 attached is without noise reduction, and picture two is with Chroma NR set to "High" (Available settings: Off, Low, Med, High) Notice how the purple vertical bar across the brown paper shopping bag and drawer on the right, as well as the horizontal one across the middle-left of the picture are significantly reduced. During the black portion of the video a few seconds before this, noise was also significantly reduced (although this would be "easier" for the filter since it is filtering obvious noise using a series of all-black frames). I will post more noteworthy results as I get into using this unit more. I found, though, that just as expected, the TBC on this unit does absolutely nothing for horizontal jitter, which is very severe on this tape. (Even though the AG-1980's TBC was off, though, that VCR still seems to reduce jitter immensely when compared to non-TBC JVC units like my HR-S9400U). Attachment 1353 Attachment 1354 |
Interesting! Not quite as dramatic as I expected, but it seems to do a good job, at least on certain aspects of the image. Looking at the date-stamp reveals a big improvement in the waviness of the image as well.
One thing I noted though -- look at the purple hue on the white cushion(?) under the cabinets on the left side of the screen, it appears to show a bit more in the after image than in the before. The reduction of edge enhancement is more prominent for certain aspects of the image than others between the shots too. Looking at the lines in the wood paneling underneath the cabinet show a big difference between shots, with the appearance of the grooves nearly vanishing as you go down the wall. However that effect does not seem nearly as pronounced when looking at the floor tiles as they move from away from the camera. Perhaps the dark color of the paneling makes the effect more pronounced. I'd be curious to see the same shot on the "low" and "medium" settings. |
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Now a test of the Median Noise Filter.
Same tape as before, but in a darker scene with some blank wall in the background and also some objects with detail to get a good overall feel for the noise reduction. Same settings as the Chroma NR test... the picture setting on the AG-1980 is "DETAIL." Decent noise reduction, but it can't keep up with NeatVideo. Not bad for a realtime solution, though. The NeatVideo example was profiled using the auto-profile feature and a blank wall in a different, brighter video frame. Picture 1: Median filter off. Attachment 1355 Picture 2: Median Filter on. Attachment 1356 Picture 3: VirtualDub NeatVideo plugin, for reference. Attachment 1357 |
Yeah, I think what might be a good idea is to start a new thread to talk about this unit. I don't have major plans during the day this Saturday... I can perform some more thorough tests and share the results.
This unit also has horizonal and vertical enhancement filters that I'd like to test out, along with a few other things. |
Going back a few posts...
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And then replying to the more recent posts... Quote:
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Still interesting, nonetheless. :) |
I've always noticed that the "detail" switch on the 1980 was essentially the same as setting the witch to NOR and sliding the soft/sharp slider to the middle position. I guess I switched it to detail because I figured it would "lock in" the middle-of-the-road sharpening setting.
As far as the median filter, the instruction manual says: Quote:
The Median Filter switch selects the following filter characteristics:- Quote:
Finally, yes I was very lazy when I ran NeatVideo that time. I need to become more familiar with it in order to get better results. I'll come back with some more test results later. |
Lazy is okay, when you're just testing. :)
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Jumping back to our SR-VD400U/HM-DH40000U tangent for a moment...
I popped in the tape used for the captures above, which has distinct time base errors. The 400U/40000U definitely has a solid TBC in it. However, I'm finding with my unit that I can't capture more than 3 or 4 seconds of MPEG2 via firewire using CapDVHS. The capture just hangs up and stops after a few seconds... I never had that issue with my HM-DH30000U's before. Any issues like this NJRoadFan? I have plenty of disk space, so that's not the problem. |
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