Digitizing VHS Inefficiency Question

[megasaja]

Hello everyone, great Forum!

I am trying for a short while now to digitize VHS tapes and am expiriencing this milde culture shock:

VHS Quality movies on the Internet in AVI format are 700 Mega Bytes or thereabout. I could fit VHS Quality Movies on a CD-
Yet when digitizing VHS tapes the same video takes up huge amounts of space.
If i could fit at least a full VHS Cassette(4 hrs) on a DVD without trouble and quality loss i could accept that, seeing that DVD's are cheaply bought, albeit even that is ridiculously inefficient.. Just wanted to see if someone here hasnt felt the same.

[sanlyn]

Hello everyone, great Forum!

I am trying for a short while now to digitize VHS tapes and am expiriencing this milde culture shock:

VHS Quality movies on the Internet in AVI format are 700 Mega Bytes or thereabout. I could fit VHS Quality Movies on a CD-
Yet when digitizing VHS tapes the same video takes up huge amounts of space.
If i could fit at least a full VHS Cassette(4 hrs) on a DVD without trouble and quality loss i could accept that, seeing that DVD's are cheaply bought, albeit even that is ridiculously inefficient.. Just wanted to see if someone here hasnt felt the same.

Hi, megasaja, and welcome. The following is just one member's opinion (you'll find lots of opinions here):

IMHO (and the opinion of many others), those 700MB movies look kinda bad. You, too, can obtain similar results by submitting your large AVI captures to lossy compression that will do a very efficient job of degrading your product into a tiny bundle a mere fraction of its original size. People do it all the time. It's easy. And often fast. Browse through the Tools section of this site and look for compression codecs. In the end, your original VHS will look better than the 4-hour compressed digital version. It all depends on your expectations.

[megasaja]

thx for you reply, however:
i'm fairly certain those movies are not worse quality than VHS, but maybe you see my point when we go the other way round:
Movies you buy on DVD are higher Quality than VHS, no? And yet digitized VHS takes something like the same space..

[poisondeathray]

thx for you reply, however:
i'm fairly certain those movies are not worse quality than VHS, but maybe you see my point when we go the other way round:
Movies you buy on DVD are higher Quality than VHS, no? And yet digitized VHS takes something like the same space..

Compression works by encoding differences between frames. When you have lots of noise, it requires more bitrate. Noise is very difficult to compress

A movie from DVD will likely be "cleaner" than the same movie from VHS source. So the DVD sourced movie will have higher quality yet take less room

So in order to reduce bitrate requirements, most people pre process the VHS transfers (clean them up, filter them etc...). This will end up consuming less bitrate, and higher subjective quality

[themaster1]

It's possible to fit 4 hours of footage on a dvd and keep pretty decent quality but not in mpeg2 . x264 would be the way to go but then no interactive menu unless you make blu ray and buy bd discs (expensive)...

[Mini-Me]

Hello everyone, great Forum!

I am trying for a short while now to digitize VHS tapes and am expiriencing this milde culture shock:

VHS Quality movies on the Internet in AVI format are 700 Mega Bytes or thereabout. I could fit VHS Quality Movies on a CD-
Yet when digitizing VHS tapes the same video takes up huge amounts of space.
If i could fit at least a full VHS Cassette(4 hrs) on a DVD without trouble and quality loss i could accept that, seeing that DVD's are cheaply bought, albeit even that is ridiculously inefficient.. Just wanted to see if someone here hasnt felt the same.

It all depends on what encoder you use: It sounds like you might be capturing uncompressed or losslessly compressed video. When I do that, a 2 hour VHS capture can take up as much as 40-60 GB. That's a great intermediate format for processing work and such, but hardly anyone actually keeps those files forever! Instead, you can further compress your VHS captures to your heart's content with an MPEG-2 encoder. By doing so, you can fit as much video as you want on a DVD, depending on how many compression artifacts you're prepared to put up with. If you just want small files, and DVD isn't your destination format, you can encode to an even more efficient format like H.264 using a good encoder like x264.

It's also important to understand a major difference between VHS captures and commercial DVD's: Commercial DVD's are encoded with very little noise, and they've generally been downscaled to 720x480 resolution from a higher quality source. In contrast, actual VHS tapes only contain about 360x480 pixels worth of luma resolution (and even worse chroma resolution), but the peaks and valleys in the analog signal don't always correspond to captured pixels, which is why we generally capture at a higher resolution like 720x480 to avoid losing information (look up sampling theory, the Nyquist limit, etc.). This difference in source resolution makes VHS captures take up as much as twice as much space as they really would in an ideal world. On top of that, the signal on a VHS tape is very noisy, and the capture process may add some noise too...and noise can take up just as much space as real detail, or sometimes even more. Both of these factors make VHS captures inherently less efficient than commercial DVD's in terms of quality/space. Video encoders have trouble differentiating noise from real detail when they compress your video, so the only way to mitigate the noise factor is to denoise before encoding.

[edDV]

Further to poisondeathray, compression result quality relates directly to source quality. Compared to digital broadcast or DVD, VHS suffers as a source in the following ways

1. Noise
2. Timebase jitter
3. Low luma bandwidth (max 3 MHz or about 240 changes across a horizontal line)
4. Low chroma bandwidth (~0.5 MHz or about 40 changes across a horizontal line)

Noise and timebase jitter combine to make even a still look like it is in motion. This causes MPeg interframe compression to fail. To get around this many people resort to the following.

1. Deinterlace (causes motion artifacts)
2. Noise reduction filters* (blurs the noise and timebase jitter to appear flat)

The result can be compressed much more but at the cost of luma detail.

Good quality source will compress without these artifacts.

* good noise reduction filters use motion detection to isolate motion from near still images. The eye perceives noise in slow moving images but not with images in motion. Problem is timebase jitter defeats most motion detectors. Everything appears to be in motion.

[orsetto]

Well, a lot depends on exactly what you're comparing to: we can't really help you unless we know what the reference is that you're trying to achieve. "VHS quality 700MB movies on the internet" is too vague: you could be referring to ANYTHING, we have no idea.

But for arguments sake, let's assume you're talking about the really good quality 700MB AVI files posted by fans of certain movie genres or TV series. You have to consider what those people are using as their source: I guarantee you it isn't moldy old VHS tapes recorded at the abandoned LP speed that no four-head VCR since 1982 has been able to play properly. Those fantastic-looking AVIs are made from high-quality studio DVDs or BluRay discs, compressed thru decent software operated by people with some good idea how to use it. Last month, I went looking for a couple Scandinavian movies that were not released in North America: the DVD rips I found were 699MB average and looked better than such movies do when shown on American cable channels like IFC. When American TV began airing a remake of the Australian comedy series "Wilfred," I downloaded the original Aussie series from someone there who had ripped the PAL dvds. All 16 episodes + a "making of" feature, in compressed AVI form, fit on a single DVD which plays beautifully on my multi-region player connected over HDMI to my 32" Sony LCD: the AVIs look as good as typical off-air network broadcasts. TV shows that originate on hi-def digital video to begin with are the best sources: until recently you could find episodes of "Big Bang Theory" compressed to approx 190MB apiece. These look phenomenal even on a large screen TV, because its difficult to screw up such pristine HD source material.

When we try the same tricks with our own VHS recordings, we don't get within a mile of that quality even at the earliest uncompressed stage. It all goes downhill from there: as poisondeathray, MiniMe and edDV noted, efficient encoding and compression is impossible when the source is noisy VHS (because noise is random frame to frame, confusing the predictive algorithms that expect small differences from frame to frame). If you happen to look at some of the VCR threads here, you'll see much discussion of the old top-line SVHS and DVHS VCRs that had built-in TBC (time base correction) and DNR (digital noise reduction). Those circuits clean up a lot of VHS crud right at the spinning video heads, so your line outputs are nice, smooth, easy to encode. But this only goes so far: removing noise means removing detail and screwing up natural motion reproduction, you trade one set of artifacts for another. And LP is LP: honestly there is nothing you can do to make LP look good (its the bastard format all VCRs gave short shrift after the very early eighties when EP took over: few VCRs today track LP well enough to get a clean encode). With SP you can fit 120-160 minutes on a DVD in passable quality using MPEG2 (DVD recorder or PC system), push that to four hours and you'll get murky mud. If the original tapes are LP or EP, DVD encoding gets progressively worse and you'll be lucky to get two hours per DVD. You can use a PC to make uncompressed AVIs instead, but these take up a lot of room and aren't likely to look stunningly better.

Transferring VHS to digital is sort of a pointless excercise: most of us are doing it to preserve a lifelong investment in recording, its a nostalgia trip: we learn to accept it looks like crap on todays flat-screen monitors. And digital video is not at all comparable to analog: it isn't a simple question of a 1:1 match, esp with the lossy MPEG2 DVD standard. Just because you could put four hours of video on a VHS cassette, and get away with it by the skin of your teeth because our beautiful old CRT televisions were fast enough to cover a multitude of sins, doesn't automatically mean you'll be able to dub those same four hours to a single DVD and not hate the sight of it. DVD is a different beast: much more than two hours of VHS dubbed to it and it falls apart. To get passable results, you need to split LP or EP tapes over multiple discs. Considering you can fit a dozen DVDs in the same storage space as a single VHS, that's not a bad compromise.

[jagabo]

4 hours of VHS at 352x576 on a single layer DVD doesn't look too bad. Especially after a line TBC and a bit of noise reduction.

[orsetto]

It would still depend what your expectations and benchmarks are, and your source tapes.

If you're a geek, you know the reality of what can and can't be achieved. You know the homemade dub to AVI (or worse, DVD) of your old Embassy Video VHS release of the "Blade Runner" European cut is not going to look a tenth as good as any random 900MB Ukranian AVI bootleg off the DVD release thats floating around. If you have the sort of mind/eye synchronicity to live with certain compromises, yes: you can shove four hours of dubbed VHS to an SL DVD at 352x576.

But those four hours of VHS had better be damned good VHS to begin with: made on a top VCR at SP speed from off-air using a roof antenna the size of a Greyhound bus. Anything less than this, and four hours of VHS dubbed to a DVD using MPEG2 blows.

The tape was recorded from 90s-era analog cable, not off air? Have fun coping with the staggering amount of "invisible" analog cable distortion and noise that will send most standalone DVD recorders and nearly every PC encoder into a tailspin.

The tape is an old commercial release with early "no idea what the hell we're actually doing but Hollywood is paying for it" MacroVision protection? Thats more fun, involving filter or TBC degradation just to get past the encoder DRM barrier.

The tape is LP? Spend the next two years combing pawn shops looking for a functional vintage Matsushita 2-head VCR that won't jitter to death and flag at LP.) EP/SLP? Thats easier, just be aware the line TBC and DNR in your super-duper VCR that cleans up SP and LP so nicely may unexpectedly decide to overlay a hailstorm of white pseudo-dropouts at EP/SLP, giving you the choice of smooth image with dropouts or noisy image with no added dropouts.

If you're using a DVD recorder instead of a PC, the recorder may have restrictions on what resolution and/or bitrate it allows when running at four or six hours per DVD (352x576 might not be an option). A single four hour DVD made from a single four hour (LP) VHS tape may look watchable, even good, on a Trinitron CRT old-school TV. On a 32, 42 or 50 inch flatscreen- not nearly as good.

Not trying to be a crank, or contradict jagabo: he knows a lot more than I do, esp about PC workflow. But I talk to a surprising number of people who are only now, in 2012, suddenly deciding they want to make DVDs of their VHS. Most of them don't want to know from TBCs, software, buying anything extra or learning anything. They fully expect to run an old LP or EP tape straight across from any random VCR into any random DVD recording hardware, cram the entire six hours onto a single 10-cent junk Staples-brand blank DVD, and have the DVD look exactly like the gorgeous compressed bootlegs they get from torrent downloads. This just isn't possible. Not saying Megsaja thinks this way, but a lot of other people do, and they shouldn't be encouraged in "magical thinking" that will lead to disappointment. Can it be done? Sure- anything can be done if you spend enough time, money and effort. Can it be done ten minutes after you decide you want to do it, using just the gear you already own? Usually no.

[edDV]

...of your old Embassy Video VHS release of the "Blade Runner" European cut is not going to look a tenth as good as any random 900MB Ukranian AVI bootleg off the DVD release thats floating around.

I managed to get the Blu-Ray Final (Director's) Cut Blade Runner for $7.99 in a Frys sale. Makes little sense to bother with SD compressed crap.

Just wait for the purchase opportunity or rent it.

[megasaja]

great replies! =)

what if i play the VHS on a large screen and capture it with a good digital camera, would that be more efficient?
i still have a CD with Star Wars Episode I on it that was captured with a digital camera in a cinema..

[jagabo]

what if i play the VHS on a large screen and capture it with a good digital camera, would that be more efficient?

No.

[megasaja]

From what i'm gathering the 2,8 GB per hour in good quality that i'm achieving with my terratec grabster av450mx isn't that bad efficiency wise. What could i achieve with more optimal hardware like canopus advc 300 and usage of codecs like divx?

[sanlyn]

Divx will give you smaller files, depending on settings. It's a very lossy compressor. You can get really tiny files with it. Don't expect a great image using Divx in that manner, unless file size is preferred over quality. There's no way to get 4 hours of high-quality digital video using low bitrates. The lower the bitrate, the less data bits you have to describe the image. The higher the compression (very high compression = smaller file size), the more data you lose.

[jagabo]

Given the same high quality source, Divx can deliver about the same quality as MPEG2 at about half the bitrate. h.264 can deliver about the same quality as MPEG2 at about 1/3, maybe 1/4, the bitrate.

[sanlyn]

There are many possibilities. Much depends on the source, how clean it is to begin with (expect plenty of noise from slow-speed tape), and how well your post-processing cleans it up. You just have to try it and see.

[megasaja]

'try and see' is a bit difficult when asking about hardware i don't own _^

[sanlyn]

codecs are software, not hardware. Almost all codecs we see around this forum are free.

[oldfart13]

...of your old Embassy Video VHS release of the "Blade Runner" European cut is not going to look a tenth as good as any random 900MB Ukranian AVI bootleg off the DVD release thats floating around.

I managed to get the Blu-Ray Final (Director's) Cut Blade Runner for $7.99 in a Frys sale. Makes little sense to bother with SD compressed crap.

Just wait for the purchase opportunity or rent it.

Well now that's the problem with a lot of cherished films that will never come out and were never released on tape or DVD. At least I'm getting good quality copies of the 12 Bomba The Jungle Boy films starring Johnny Sheffield off TCM. No release for those. How about The Devil's 8 with Fabian? No release. Tons of others. This is why some of us choose to preserve the old films that we like...whomever owns the rights (and even that is up in the air on many titles) won't release them.

[edDV]

...of your old Embassy Video VHS release of the "Blade Runner" European cut is not going to look a tenth as good as any random 900MB Ukranian AVI bootleg off the DVD release thats floating around.

I managed to get the Blu-Ray Final (Director's) Cut Blade Runner for $7.99 in a Frys sale. Makes little sense to bother with SD compressed crap.

Just wait for the purchase opportunity or rent it.

Well now that's the problem with a lot of cherished films that will never come out and were never released on tape or DVD. At least I'm getting good quality copies of the 12 Bomba The Jungle Boy films starring Johnny Sheffield off TCM. No release for those. How about The Devil's 8 with Fabian? No release. Tons of others. This is why some of us choose to preserve the old films that we like...whomever owns the rights (and even that is up in the air on many titles) won't release them.

In those cases you need to deal with what you have but for popular releases there are high quality source files. No need to fiddle with VHS.

I cap old VHS mainly for nostalgia local programming, documentaries and major news clips. Also, some of the best are music performances from the 80's that will never be released due to quality.

[edDV]

Given the same high quality source, Divx can deliver about the same quality as MPEG2 at about half the bitrate. h.264 can deliver about the same quality as MPEG2 at about 1/3, maybe 1/4, the bitrate.

That only works with "high quality source", not noisy-jittery VHS.

[lordsmurf]

Garbage in, garbage out.
It's really not much more complex than that.

You can, of course, work to make the "out" look less like garbage.

But a VHS tape will never look like a DVD or Blu-ray release remastered from studio film archives.

[megasaja]

i dont want it to look better, VHS quality is fine by me- i just want the filesize to stay reasonable -which has to be a consideration for people who want to digitize a whole library of tapes(300+ in my case).
converting dv-avi into h.264 gives my mediacoder trouble, did someone here do this before and can suggest the right tool for conversion?

[orsetto]

megasaja, not to beat a dead horse but you still haven't given us the slightest clue exactly what kind of VHS you're trying to digitize. You may think it doesn't matter, but it does. All this chatter about starting with lossless AVI then shrinking the file size with H.264 or whatever secondary codec doesn't mean jack if the source tapes don't have enough real video information to support being shrunk and recoded. This can be even more crucial in a PAL country like Germany (the glut of badly-coded, to the point of unplayable, compressed PAL VHS files posted online should scare you). Top-quality recent Hollywood studio VHS releases MIGHT tolerate this treatment, off-air recordings of perfect-reception TV might. Everything else? Forget it: you need to recalibrate your expectations and not get carried away with misguided notions of "efficiency." First of all, this may come as a shock to you, but your "300+" tape collection is laughably small compared to the average video-addict here (who typically has 1500+ tapes to cope with). Even with the most common "inefficient" workflow of using a DVD recorder and keeping to two-three hours per DVD would contain your entire digitized collection within 10-12 "50ct" DVD cakeboxes occupying the space of 50-60 VHS tapes. If you stuff it all onto a dedicated external HDD, it will take a mere three VHS worth of physical storage space.

Assuming you don't care about backing up to non-HDD optical media, and your efficiency quest is strictly related to bang-for-the-buck HDD storage, your options are still fairly limited. What LordSmurf said about "garbage in, garbage out" is a twisty road that doesn't always lead where you'd expect. It is logical to assume crummy quality VHS video can be shrunk to small file sizes more easily than good quality video, but often the reverse is true. Really superb SP-speed VHS can be shrunk down in HDD file size: somewhat (not nearly as much as you'd hope). Blurry, noisy, or slow-speed VHS that appears to have little to no picture detail is actually much harder to digitize, requiring more bandwidth to preserve what little detail exists and handle the "invisible to your eye" underlying signal defects. As I've already mentioned, this is much more important now with our standard-def-hostile flat screen displays than it was with CRTs: a good CRT concealed an amazing amount of visual gunk, a capability flatscreens aren't even close to achieving even after a decade of rapid evolution. Maybe in ten more years, as OLED and other dramatically-better technologies become affordable enough to replace the lousy commodity LCDs we have today.

More and more, I'm getting the feeling all you really want to do is find an "efficient" way to store your entire VHS collection on your main computer HDD for easy access without it dominating the drive. If I'm right, your answer is as simple as "delay your digitizing project until next fall." Prices for HDDs are currently way off track due to factory damage in Thailand. Once new factories come up to speed, HDDs will resume their rapid trend of offering ever more storage for ever smaller prices. Wait until you can once again buy a 2 TB drive for $100, and your "efficiency" dilemma is solved: buy a great big cheap primary HDD. As an alternative, look into getting a BluRay burner: a single BD-R will hold about 10 hours of decently-encoded VHS (it won't be directly playable on a BD player, but makes nice efficient "offline" file archives).

[megasaja]

AGFA GX E-240 VHS Pal Secam Made in Germany
like this only 240 minutes..

€dit: I wanted to store on dvd
Edit2: i would call anyone misguided who accepted a ratio of worse than 1dvd/1cassette while digitizing 300 tapes, or just desensitized to producing mountains of electro junk down the road

[poisondeathray]

€dit: I wanted to store on dvd

dvd media, as in a data disc that can hold different formats such as h.264?

or dvd-video as in authored and playable in a dvd player ?

Your inefficiency question has already been answered to death - noise, motion are all hard to encode, difficult to compress. Either you clean it up and stabilize it using hardware +/- software methods, or take (easily) 2-10x more storage room (I'm assuming this is typical VHS footage)

[megasaja]

on disc
care to elaborate on those cleaning up methods?

[poisondeathray]

on disc
care to elaborate on those cleaning up methods?

So you're using DVD5 media as data disc storage - not an authored DVD playable in a regular DVD player

Of course the methods used would depend on the source condition. Ideally you would use a TBC + software . Have a look at the various sub forums like the capture forum and restoration forum, or at least post some representative footage. For example , is this professionally shot footage, tripod, rigs with lighting setup? or some handheld home video. BIG difference.

Even pristine retail VHS tapes have noise and can benefit from processing.

There is a lot to learn, or were you more interested in a simple solution, not caring much for quality ?

Edit2: i would call anyone misguided who accepted a ratio of worse than 1dvd/1cassette while digitizing 300 tapes, or just desensitized to producing mountains of electro junk down the road

This is quite low bitrate; 4hours / 4.37GB is about 2.6Mb/s, not even counting the audio or overhead.

Everyone has different opinions on acceptable quality or quality loss

There are a bunch of tradeoffs you'll have to make

[megasaja]

thank you poisondeathray, i'll try to post some footage later, from digitizing with the terratec media grabber av450mx
on a different note: i could get a pinnacle studio moviebox dv firewire for little money. is that a preferable device to the one i'm using, seeing that the grabster wants to encode directly into mpeg2?