More on saving VHS as DVD

wufred wrote on 10/28/2008, 4:04 AM
I read many of the threads in this forum regarding converting old VHS tapes to DVD, especially appreciate the time and again John's mention of option #1, recording directly through a camera to a DVD recorder. My question has to do with what is the best way to preserve the maximum amount of information, (quality). It seems that I can only record my video as VOB files using my Daewoo recorder. I am worried that there is so much compression that I will be loosing more of the already scant quality that I have left. If I want to save them as mpeg2, I would have to do Option #2, and indeed, I do have too many tapes. Am I worrying too much ? I just don't know enough about formats and compression that may be I am more dangerous to myself than not knowing anything at all. btw, John also mentioned somewhere that you break your files up to 20min segments, were those mpeg2 files ? I also have many many hours on D8 tapes, does it make sense to break them up and save them as avi files on multiple DVD's?

Comments

farss wrote on 10/28/2008, 4:49 AM
If you capture your VHS tapes as DV AVI files then you can fit 20 minutes worth onto a DVD as a data file.
D8 tapes can be transferred to DV or DVCAM with no loss or recompression. That's definately the best option for them.

Bob.

Chienworks wrote on 10/28/2008, 5:48 AM
If you're going to save the old VHS video as DV .avi files in 20 minute chunks, i think it makes a lot more sense to buy a few extra hard drives and store them that way. A DVD disc with 20 minutes of DV on it isn't very convenient. You won't be able to play it in a set-top player. You may not even be able to play it on your PC without copying it back to the hard drive first. And, you'll need 6 discs to hold 2 hours worth of video. That's a lot of disc shuffling.

On the other hand, a 500GB external hard drive available for under $100 these days will hold over 35 hours of DV, or about 105 DVD's worth. You can store an enormous library of video in one little package while you pick and choose which scenes you want to make video DVDs from.
farss wrote on 10/28/2008, 6:19 AM
You'd trust a HDD for as long as VHS has held up on a shelf?
Even duplicate HDDs don't improve the situation.
More troubling is that 5 of them in RAID 5 aren't as reliable as I thought they'd be either. So far so good, none of the drives in my RAID have failed but I need to find something more reliable in the next few years.

Bob.
johnmeyer wrote on 10/28/2008, 9:01 AM
If this is VHS, and not SVHS, try encoding to MPEG-2 at 6,000,000 bps or higher (average) and then encode the same thing to DV AVI. Play back both files to your TV set. If you can tell any difference, then you have better eyes than mine.

My point is that VHS is pretty yucchy quality (technical term), and MPEG-2, if properly encoded, will give you results that are pretty much as good as the original, as long as you keep the average bitrate pretty high. Heck, even with pristine DV, if I encode at 7,500,000 bps average, I have a VERY hard time seeing any difference, even with extremely fast motion. I did LOTS of test several years ago on basketball footage taken in a well-lit gym of video taken with a DV camcorder. You have the ball, the lines on the court, and the players all moving against various backgrounds, with the camera zooming and panning. It's a great test for encoding. I could easily see differences as soon as I went below 7,000,000 bps, but if I kept the average well above that, it was extremely difficult to see the difference. I then did some work with external encoders and those small differences disappeared. Since the crispness and resolution of DV is many times greater than even good VHS, much less the average stuff that is on most tapes, I can tell you from both testing and from experience that you'll be just fine encoding to MPEG-2.

At 7,000,000 bps, you can get almost one hour and twenty-five minutes onto a single DVD. If you want to fit an entire 2-hour VHS tape onto one DVD, you'll either need to go down to 4,800,000 bps, at which point you'll need to use 2-pass encoding, or you'll need to use dual layer media. If you use dual layer media, you can easily fit two hours and thirty minutes of video at 7,000,000 bps. In fact, you can encode at 6,000,000 bps and fit three hours, which is exactly half a 6-hour tape. Since the 6-hour tape quality is REALLY bad, 6,000,000 bps is plenty enough. So, get a bunch of dual layer discs, and a bunch of 2-DVD cases, and just encode directly to dual layer at 6,000,000 and you can have one DVD case for each 6-hour tape.
John_Cline wrote on 10/28/2008, 2:27 PM
John, I'm going to have to respectfully disagree with what seems to be your contention that the poorer the quality of the video to begin with, the lower the bitrate you can use to encode it to MPEG2. In my experience, exactly the opposite is true.

Since 6-hour mode VHS is quite noisy, virtually every pixel in the image changes a great deal from one frame to the next and this is a complete worst case scenario for MPEG2 compression. If your video is extremely clean and has very little movement, you can encode at much lower bitrates and get great results. If the video is noisy or has a lot of movement, then you must encode at a higher bitrate to obtain acceptable results.
musicvid10 wrote on 10/28/2008, 2:36 PM
Many set-top combo units have built-in noise reduction an enhancements optimized for VHS -> DVD conversion.

My Panasonic unit advertises and comes through with DVDs that are in many cases superior to the original VHS, and certainly much better than anything I've been able to accomplish with VHS -> Canon camcorder -> Firewire -> DV-AVI capture on my computer. Keep your material to <= 2 hrs per DVD (T-120 SP) and the results are better than one might expect, even with my decades-old off-the-air recordings.
johnmeyer wrote on 10/28/2008, 2:40 PM
John,

I agree with you that noise is a bitch to encode and requires a higher bitrate in order to get the same apparent quality for the real motion in the video. However, I still stick with my original statement because the spatial quality of VHS is so low that it doesn't take many bits per second to capture both the spatial detail and the temporal movement. I recommend that anyone planning to encode a large number of VHS tapes to DVD do some testing. Try different bitrates, and also different resolutions. Remember that you can encode a legal DVD at resolutions lower than 720x480. You might want to try 352x480, which Vegas does support (Vegas does not seem to support 352x240, and I wouldn't recommend that resolution anyway).

Back to John's point, if you are going to encode in Vegas, then applying a LITTLE noise reduction from Neat or Mike Crash's implementation of the VirtualDub denoiser will certainly produce better results.

But, my main point is this: TEST, TEST, TEST. There is no cookbook for this stuff, and you have to look at the results yourself before you commit weeks of your time to a big project. I still think that MPEG-2 will provide terrific results that will be so close to what you would get if you were to save as DV that I don't think most people will notice the difference.

IMHO, saving VHS tapes to DV format is nuts.

musicvid10 wrote on 10/28/2008, 6:14 PM
**IMHO, saving VHS tapes to DV format is nuts.**
John, now I'm confused. Going from a VHS deck through a camcorder with DV-out to firewire to a capture utility, how could you capture and save it as anything but DV?
johnmeyer wrote on 10/28/2008, 6:29 PM
John, now I'm confused. Going from a VHS deck through a camcorder with DV-out to firewire to a capture utility, how could you capture and save it as anything but DV?Yeah, I guess I could have said things more clearly.

Yes, when you bring the video in through the DV camera pass through, you will normally save it as DV video. However, you CAN take that connection and save it directly to MPEG-2 (just use a capture application that does real-time MPEG encoding). Alternatively, you can go ahead and save the captured file as DV, but then encode to MPEG-2 and save that file on your permanent storage (DVD or hard drive) instead of the DV file.

I think the confusion comes from the word "save." I was using it to mean what you do with the final, ultimate file you create, and was not referring to any intermediate file that results from the capture.
farss wrote on 10/28/2008, 6:54 PM
"I don't think most people will notice the difference"

That's very true and a very dangerous way of evaluating outcomes. Most people can't hear the loss from mp3 encoding either.
It's completely irrelevant for archival purposes because at some point in the future the media will again undergo another format shift and the errors add up cumulatively and possibly horribly.

An example of this is one of our local broadcasters decided to dub their huge library of 2" and 1" tapes to BetaSP, it looked just fine even on their high end monitors. Recently they've had to shift all that SP to Digibeta and it looks bad. Dubbing straight from the 1" masters to DB the results are way better. The costs of going back and re transferring warehouses full of tapes is staggering.

One could argue that DV itself is not good enough for archiving VHS where the intent is to retain as much of the original data as possible. Saying it looks good enough is not the benchmark at all!

Of course all of this depends on what the intent is. If it's just home movies that'll NEVER be of any commercial value and where it's unlikely no one will even be interested in them after a generation then anything goes. On the other hand a long time ago a lot of material was considered to be of no ongoing commercial value and yet today it is.

Bob.
musicvid10 wrote on 10/28/2008, 7:33 PM
**On the other hand a long time ago a lot of material was considered to be of no ongoing commercial value and yet today it is.**

Hehe Bob, I've often wondered what it would be like for future archaeologists, millennia after the next Pompeii, coming across millions of polycarbonate discs, and their reactions upon listening and viewing them after figuring out the primitive technology needed to decode them. Just a persistent musing . . .
johnmeyer wrote on 10/28/2008, 7:47 PM
That's very true and a very dangerous way of evaluating outcomes. Most people can't hear the loss from mp3 encoding either.But Bob, this is VHS tape, not Beta SP. The initial quality is already junk. I have done MP3 encodes of AM broadcasts and I am in no way worried about accumulated errors or losses. It just won't be noticed given the 6kHz fidelity, static, fade, etc. of the original AM. Same thing with VHS. And, as already noted by another poster, the act of digitizing often makes the video look better than the VHS because there is an inherent elimination of any time base errors (because there is no time base once it is digitized, meaning that there is no longer an analog timebase that can shift or degrade with additional generations).
farss wrote on 10/28/2008, 8:19 PM
Agreed the initial quality is junk. The question is how much junkier does it get and how much of the information that could be used to correct the junk is lost in the process of digitising it.
Time base correction obviously improves the image. What is the impact of DV's chroma subsampling and 8 bit quantization compared to analogue video. I don't know the answer to that of course.
What I have seen and heard though is that great quality vision and sound will withstand all manner of compression way better than the poor quality material i.e. the bad stuff needs lots of TLC to avoid making it even badder. But what I don't know is even if it looks OK how it'll hold up over subsequent recompressions and format shifts or what impact throwing data away today will have in decades to come when someone tries to restore the sound or vision using more advanced technology.

Bob.
corug7 wrote on 10/29/2008, 12:51 PM
To quote Strother Martin, "What we've got here is a failure to communicate."

The original poster was concerned about the quality of his VOB files from a standalone DVD recorder over the quality of MPEG-2. The reality is that VOB files ARE MPEG-2 wrapped in a way that will play back on a DVD player. So, my friend, you have MPEG-2 already, and if you were to create a DVD with the MPEG-2 files you created in Vegas, they would become VOB files also, usually without recompression if you encoded them properly.

The hardware encoders on most of the DVD recorders out there today are pretty good. Some are great, rivaling the excellent Minerva Publisher encoder we used in our workplace up until last year (and which cost about $50,000 when new, if I'm not mistaken). Your Daewoo DVD player is probably doing just as good as the Mainconcept codec would, especially if you are keeping the recordings in the one hour mode. Two hour mode usually drops you down to about 5 Mbps, which can still be very good if there isn't a lot of motion. On most of these recorders, 4 hour mode drops you down to 352 x 480 resolution, which is still pretty good. I have noticed that color sampling tends to take a hit here. 6 or 8 hour mode is usually MPEG-1 at 320x240 resolution, and can range from acceptable on some recorders to unwatchable on others.

To clear up a statement made earlier by one of the Johns, the DVD spec does not support MPEG-2 at 352x240. It uses MPEG-1 for this and the accepted bitrate is usually no higher than 1.8 Mbps for video.

That said, the original poster may get the best quality going directly to his recorder. For better quality, he may want to run the video through a Time Base Corrector first. Some consumer versions, such as the Sima CT-200, can be had for as little as $50.00 US and work quite well for what they are.
jazzmaster wrote on 10/29/2008, 1:34 PM
Other great Strother Martin quotes from "Cool Hand Luke":

"When a man's mother dies, he tends to get rabbit in his feet. So we're lockin' you up tonight. It's for your own good, Luke."
(Luke: I wish you'd stop bein' so good to me, boss.")

"You run onct, you git one set o' chains. You run twict, you get two set o' chains. Ain't gonna be no third time, cause we gonna get your head straight."

"Well...like I tol' ya...he brought it on hisself."


(sorry for this!)
wufred wrote on 10/30/2008, 2:47 AM
John, John, Bob, Kelly and everyone else, thank you , thank you very much for spending time to answer my posting. You are all the trusted and respected pillars of this forum. I have made searches so many times and have gotten so many answers and learned so much. I think I do speak for many who visited, thank you !!
I am looking for the best method, or methods, to help archive 49 years of performance for a dance troupe. The tapes started from half inch B/W tapes on 6" and 8" reels to professional Betacam, to VHS, Analog 8, Digital 8 and now DV. They do come in an exceedingly wide variations of quality. (In fact, can someone tell me if it is even possible to enhance the white-out faces of dancers when they end up in the bright follow spotlight when cameras did not have autoexposure capability.) It will be a labour of love, but I would still like to control it to a reasonable, manageable and sane amount of time.
I do worry that if I do not save the data in the best quality I know today, newer technologies come along and I'll end up doing a disservice to this remarkable piece of history. That's why I thought about saving in the avi format. I am worry too how long I can keep the data and how reliable are the 1Tb drives that I can buy today for $199 at Fry's. I know V8.0 will render at 6Mb bitrates, should I set the minimum to 6Mb as well ? I also great confidence in John's test data, but for testing myself, I don't have the equipment nor the experience to tell a good video from a better video.
My tendency right now is maybe to use my recorder to do the really old tapes, and move up to capturing and rendering into high bitrate mpeg2 for the more recent ones. What really is the difference between VOB and mpeg2 ? and how do I properly encode with minimum loss ?
I am sorry if I started some technical debate, but I believe they are all for exchange of great ideas and opinions. If you guys have more ideas please keep them coming, this was indeed the kind of discussion I was hoping to learn from, but did not dare to ask for.

lynn1102 wrote on 10/30/2008, 5:47 AM
I'm going to throw one more suggestion in here. If these are that valuable to you or anyone else, make sure you use archival quality discs. I have had event masters sit on a shelf here for 6 months and refuse to play on anything. I have had some actually separate while sitting on the shelf. The slight extra cost will be worth it.
Our local historical society started storing much of their stuff on dvd in the past few years. They also found this out the hard way, and now use "medical" type archival discs.

Lynn
RexA wrote on 10/30/2008, 5:51 AM
I've often wondered what it would be like for future archaeologists, millennia after the next Pompeii, coming across millions of polycarbonate discs, and their reactions upon listening and viewing them after figuring out the primitive technology needed to decode them.

Assuming the remnants of our civilization are lost by the time the discs are found, I would think figuring out that they contain data and extracting that to a binary stream would be a difficult task. Then the archaeologists may gradually figure out that there are different types of streams and extracting some with simple coding like text may lead to stuff to examine for years to extract the ancient language.

Figuring out that some of it is video and reverse engineering the encoding method, seems to me ultra difficult. Jpeg or mpeg don't seem obvious to me unless you have a priori knowledge about what the encoders were thinking. Add encryption that most of us can't crack when we know the content, and I think it gets prohibitively difficult.

Should we be sending messages to the future? CDs or DVDs probably will last, but are they any kind of record? Look at the ancient rock scratchings that we only partially understand now. Film would be intuitive if it lasts, but the digital versions without lots of easy hints saved too... I think just shiny disks.

Do we care? Maybe we can stop Hollywood and megacorps protection schemes as preserving a possible message to posterity?

It'll be a short period anyway, it will either be all evaporative data streams soon from the megacorps disks or we'll be back approaching the stone carvings soon.

johnmeyer wrote on 10/30/2008, 10:20 AM
First, you cannot save or do anything to improve burned out faces. Underexposure can sometimes be corrected; overexposure cannot. The details are gone.

But your last point brings up a FAR more important issue than whether you save in MPEG-2 (and VOB is the same thing, as was astutely pointed out by someone else) or DV or any other file format. As I've stated several times, I don't think this is going to be a big deal, either now, or in the future if your work gets transferred to some future format. So, go with the more compact and easier to produce format.

However, now that I understand the specifics of what you are doing and the scope of your project, the more important issue is the quality of your transfer. I won't re-iterate all the posts I've made on this subject over the years, but the difference between capturing analog video correctly (the correct cables, the correct equipment, the proper settings on that equipment -- most notably the dub switch on VHS decks -- and also the post capture settings will all make a HUGE difference in the quality of your work.

I recently did a disc -- strictly for my own use -- which recreated a commercially produced performance from bits and pieces that had been transferred to several DVDs by the studio, combined with the complete performance which was only released on VHS tape back in 1985. The trick was to make the VHS transfer good enough that it would look the same as the DVD.

I achieved that goal.

While you can see the change in detail when the video cuts between the DVD and the VHS segments, I was able to completely eliminate all the VHS artifacts -- chroma noise, luma noise (snow), fringing, etc., and was able to use Vegas to get the color and contrast to match almost exactly. I am very proud of the results and am sorry I cannot share it (since it is copyrighted material and I am doing this only within the confines of my own home).

The point is that if you capture that old video by tuning to channel three, or without a TBC (which you may need for some of that really old stuff), you may end up with something pretty bad, when it could actually be pretty good.

So, don't worry about the capture format. Just go ahead and use your DVD recorder with the parameter set to high, but DO spend a lot of time making sure you have perfected your analog to digital capture techniques.



craftech wrote on 10/30/2008, 11:10 AM
I can see the point of converting VHS home videos to DVD if you don't have anything better than VHS or 8mm originals, but at $5 each for commercially produced DVDs from places like Walmart, what is the point of going through all that to convert VHS movies over? Throw them out and go buy $5 DVD versions. If space is a problem throw out the jackets and put several of them in double or triple DVD cases. Or are we talking about rare movies?

John
johnmeyer wrote on 10/30/2008, 11:44 AM
what is the point of going through all that to convert VHS movies over? I agree, but I think that wufred is trying to convert his personal collection of dance recitals. My project was to recreate an original performance, and there is no complete DVD of that performance, only a few select pieces that have been transferred to biography DVDs, and highlight DVDs. The complete performance was only released on VHS tape, and will probably never be released on DVD, hence my work to create the best possible VHS transfer, and then overlay the better DVD video and sound when that was available.
wufred wrote on 10/31/2008, 1:55 AM
Thank you John for all the valuable advice, I will go shop for a good TBS, some high quality discs, and make sure I use good cables. I would actually try to experiment a little as well.
hazzardm wrote on 10/31/2008, 6:58 AM
I also have this VHS transfer task on my list for an upcoming anniversary party next spring. I appreciate all the adivce provided. There were 2 acronyms used in this thread that I searched for, but cannot track down a definition for:

TBC and TBS

Thanks
craftech wrote on 10/31/2008, 10:44 AM
TBC and TBS
==============
TBC is a Time Base Corrector which is used to improve the quality and stability of video signals.

TBS I never heard of.

John