OK, now that we know what laserdiscs are and why they never achieved mass-market adoption,
let’s look at some of the technical details of the format as well as how it evolved overtime.
So first, I haven’t yet made the exact distinction between CAV discs and CLV discs.
These stand for Constant Angular Velocity, and Constant Linear Velocity.
Their names explain the difference.
A CAV disc rotates at constant 1,800 RPM.
Each rotation contains exactly one frame of video.
This encoding method was simpler and let the player do some neat things, but it limited
recording time to 30 minutes per side.
A CLV disc slows the disc’s rotational speed as it progresses.
See, as the laser moves towards the edge of the disc, the circumference of the disc along
the spot it’s reading continually increases.
Constant Linear Velocity encoding slows the disc down as the laser progresses to keep
the speed of the disc relative to the laser constant, rather than keeping its absolute
rotational speed constant.
This allowed recording an hour per side of the disc.
But it also could increase crosstalk noise, and because the number of encoded frames per
revolution was constantly changing, the trick-play features of the CAV disc were eliminated.
Pioneer would reduce crosstalk by modifying CLV into CAA, which slowed the rotational
speed in steps.
CAA, standing for Constant Angular Acceleration, was more of a behind-the-scenes alteration,
though, and these discs were still marked as CLV on their sleeves.
Real cinephiles want CAV discs.
There are a number of reasons for this, but one of the most interesting is the way the
discs are indexed.
Play a CLV disc and the display acts like you would expect.
You get the chapters available, and the time counts up from zero.
But a CAV disc, well just watch.
That’s right, these are frames.
In a CAV disc, each frame is directly accessible by number, and you can simply type in a frame
number and the player will nearly instantly get to it.
And that freeze frame is perfect.
This opened up a lot of interactive possibilities.
Of historical note is the Museum of Science and Industry in Chicago’s use of Laserdiscs
to allow guests to view every front page of the Chicago Tribune newspaper.
This was back in 1980.
There were also arcade games--and even home video game systems--developed which used laserdisc
as a random access video system.
Remember how I said the collector’s market saved laserdisc from dying completely?
Well, much of that was due to special editions like this Pocahontas box set.
I know, there could be better films to explore, but this box set is actually perfect for showing
what Laserdisc had to offer.
Look at all this extra stuff!
The first three sides are the film itself in CAV format.
The analog soundtrack contains a commentary track on the left channel, though it’s mastered
very, very poorly for some reason.
[COMMENTARY: Yeah the Turkish sword on John Smith’s back, that was, uh, I think John
Pomeroy was the one who, uh, who led the character in animation.]
The right channel contains dolby digital sound.
[Digital static sounds]
--more on that briefly.
The fourth side is in CLV, as it’s an hour long making-of feature.
But the third disc is where it gets really interesting.
First of all, look at all these chapters.
There are 48 alone in special features.
But the Laserdisc was able to tell the player to freeze the frame.
This was used extensively in box sets like this to organize collections of still images.
I’m not going to show you much of the actual content, because I don’t really want to
get in trouble with Disney, but I will go through some of the title cards so you can
get an idea of how this is navigated.
After a brief intro, the disc automatically stops and you see the little leaf with STEP appear.
That’s because what follows is a sequence of still frames.
If you press play, the player will just resume normal playback and you’ll get an infoblast-style
mess until it receives the next command to stop.
But on the remote, the STEP button allows you to advance just one frame at a time.
And since each of these frames has a discrete number, you can get back to it simply by entering
the frame number.
When there’s a segment of actual video, the leaf instead says PLAY so you know what
to do next.
You’ll see that there are also a lot of commentaries here as well on the analog tracks.
Sure, the special features section on a DVD can do all these same things, but it’s really
something that an analog format from so long ago can do it, too.
And I’m left to wonder if there’s anything on these Laserdiscs that hasn’t made its
way onto a DVD or Blu-Ray release.
In fact, there’s a lot of content on Laserdisc that hasn’t left the realm of Laserdisc.
And one more thing before we move on, the search-by-chapter nature of the laserdisc
made it prime material for the education market.
This disc here, well it’s a weird one.
A showcase of computer generated imagery from 1986.
I kid you not, this disc is the vaporwave community’s dream, and I know this because
when I learned what vaporwave was, there was a video featuring this laserdisc’s opening clip.
[Distinctly 1980’s, synthesized Jungle-like music]
Ah but there’s more.
There’s this:
[NARRATOR: This time consuming process creates highly detailed and spectacular images]
...and this...
[INTERVIEWEE: Where you’re trying to get across a look and a feeling in ten seconds,
you can pick some perfect blue for your object… but you don’t know what color it’s really
going to be until you light it]
...and it also features this creepy talking head!
[Fulfilling absolute decree in casual simplicity]
I’m fairly sure this was meant as an educational disc, but I’m not certain.
Oddly enough, the Voyager Company, the producers of the disc, was the publisher of the Criterion Collection,
perhaps the most famous collector’s edition laserdiscs.
Anyway, having near instant random access to any part of the disc made Laserdisc great
for teachers.
If there was a particular clip that would easily show a concept, you could cue it right up.
This was particularly useful in science classes, to show experiments quickly.
A VHS tape would require a lot of effort and patience to cue up, but if the lesson on Newton's
Third Law of Motion was Chapter 14 of a Laserdisc, just type in 14 and you’re ready to go.
On that note, CLV discs took significantly longer to cue up a new chapter.
Because of the disc’s enormous size, it takes a while to speed up and slow down.
So when searching for a chapter that’s well away from the start, the disc needs to slow
down a lot to get to the correct speed.
The laser doesn’t take much time to get from one chapter to the next, but it has to
wait for the disc to get to the right speed before it can actually play.
Now I’ve stepped a little far ahead here, showing discs with digital sound and Dolby Digital.
Let’s take a step back and look more at the evolution of the format.
I had mentioned in my introductory video on Laserdisc that while the format began its
life as a product of a joint venture between Philips and the Music Corporation of America
called Discovision, the Pioneer company of Japan would sort of take over the format.
They were part of the official renaming of the format to Laservision, and they were the
ones that branded their own players as LaserDisc.
From the mid 1980’s until the end of its life, Pioneer was almost the only manufacturer
of Laserdisc players.
There were others, with Sony producing a good show, but it was Pioneer that kept pushing
the format and adding new innovations.
Perhaps the first major innovation was the use of a solid state laser.
You might have noticed that this machine is massive.
It’s a lot wider that the VCR we were putting it up against, which itself is big and bulky,
and this by far the largest piece of A/V equipment I have ever run across.
Much of its width comes from the laser carriage.
Initially, Laserdisc players used a helium-neon laser tube as its source of laser light.
This tube is quite large, and so is the necessary optical path the beam has to make to be focused
onto the disc and reflected back to the light sensor.
I’ll be doing a teardown of this machine in a later video, but let’s take a quick peek.
This entire carriage moves left and right as it scans the disc.
Oddly enough, this tiny little motor is responsible for moving this whole thing.
And yes, that black crud is from the completely disintegrated belt that was on here when I
got this machine.
I have a somewhat suitable replacement on here, but it seems to have trouble reversing
the carriage.
It advances just fine, though.
Inside this black plastic shield are a pair of mirrors attached to small wiggly things,
and by shifting the angle that the beam hits the glass ever so slightly, you could maintain
fine tracking on the disc.
See, unless the disc is exactly perfectly centered, which with this fine of a data stream
it most certainly won’t be, the laser will need to be constantly moving left-right-left-right
to follow the spiral groove of pits.
I strongly suspect that’s what’s wrong with this player, as it exhibits severe crosstalk
when playing a CAV disc.
It does appear to be able to maintain focus distance, as the objective lens can move and
it produces a picture, but without fine tracking control the output will be a mess.
I don’t want to get started on this project quite yet, though.
That will have to wait…
In either 1983 or 1984--it seems there's some date disagreement--Pioneer introduced the
LD-700 player which incorporated a solid state laser.
This was also the first player to introduce a tray-loading system.
By switching to a solid-state laser, the machines could be much smaller as the laser assembly
was a small fraction of its previous size.
But there was a small compromise made.
The helium neon laser produced a red-orange light, but the laser diodes used in Laserdisc
players shared the same infrared light of the compact disc audio format.
The longer wavelength of the infrared light couldn’t be focused quite as tightly as
the shorter wavelength red-orange light.
This meant a player with a solid state laser would be more susceptible to crosstalk, and
scratches or other damage to the disc would affect its ability to read the pits to a greater
degree.
However, the many advantages of a solid-state laser pickup system greatly outweighed this
single disadvantage, and thus infrared became the way to go.
By 1984, it was clear that Laserdisc would stay in the realm of the videophile, as the
videocassette recorder seemed perfectly fine for the masses.
With that in mind, Pioneer started adding new features to their players and updated
the format along the way.
The first main addition was that of DIGITAL SOUND!
Hah, you thought FM stereo wasn’t enough, how about uncompressed 16 bit stereo PCM audio!
When introducing a player with digital sound capabilities, Pioneer killed two birds with
one stone by also letting it play the newly introduced Compact Disc.
The digital audio on a laserdisc is encoded much the same as a CD, so Pioneer already
had the circuitry onboard to process the digital audio from a CD.
Thus the CLD-900 could play both.
Weirdly, though, this player contained an odd mechanism with two separate spindles with
one for holding a CD and the other a Laserdisc.
Looking on the laserdisc archive, it seems many early players were designed this way.
I’m guessing this was due to difficulty in designing and controlling one spindle motor
capable of spinning both the massive LaserDisc and the tiny CD correctly.
Eventually, though, a single spindle with a collapsible center was used for both CDs
and Laserdiscs.
Because laserdiscs held two separate audio tracks in NTSC discs, one of these could be
replaced with the digital soundtrack while the other could remain as an analog conventional
soundtrack.
A signal on the disc would indicate to the player that the disc contained digital sound,
and it would switch to the secondary soundtrack containing the data.
The analog soundtrack stayed on the primary channel, and older players would just ignore
the signal to switch to the secondary track.
But the addition of digital audio caused some compatibility issues.
For one, PAL discs didn’t have two separate audio tracks.
Not sure why, but they didn’t.
This meant that a PAL laserdisc was either digital or analog, and an analog only player
could not play a disc with digital sound.
This probably didn’t help the already poor sales in Europe…
At first, pioneer had to sacrifice playing time to fit digital audio on the discs.
The first digital audio discs only held 55 minutes per side, which left some titles like
this copy of Back to the Future released as analog-only even though digital sound was
available at the time of its release.
Because this film is one hour and 56 minutes, it would fit on a single disc with analog
sound, but would need a second disc for digital sound.
So they stuck with analog to keep it on a single disc.
[DOC BROWN: This is truly amazing.
A portable television studio!]
By 1987, Pioneer had figured out how to get an hour runtime and still have digital sound.
Hey look, MCA!
Then we get to surround sound.
Laserdisc was pretty much the only way to get true surround sound until DVD came along,
but the way surround was encoded was, to put it kindly, messy.
If a disc contained a Dolby AC-3 soundtrack, the AC-3 data was FM-modulated on the right
channel of the analog track, and required the use of a receiver capable of demodulating
this into a digital output.
Modern receivers don’t have this functionality, so to get the Dolby AC-3 soundtrack off a
laserdisc requires an external AC-3 demodulator.
But because a Dolby AC-3 encoded disc uses one channel of the analog track and leaves
standard stereo digital sound in place, these discs can only be played in mono on an analog
only laserdisc player.
Not that many of those stuck around for very long, as once digital sound was introduced
nearly every player manufactured could utilize it.
Then there’s DTS audio.
A DTS encoded disc uses the digital tracks, so to play it on a normal player required
switching back to the analog tracks.
As an example, this copy of Casper has a DTS soundtrack because if there’s any movie
that needs DTS surround, it’s Casper.
When you play it, the player doesn’t know it shouldn’t be reading the digital track,
and it’s producing a garbage output.
You need to manually switch back to the analog soundtrack if you want to hear the movie.
So, if you wanted digital surround sound, you’d need to match your player to a compatible
receiver, and then also make sure you’re buying the right discs.
There certainly are people who are that dedicated, but not many.
OK, so aside from format technicalities, let’s look at some of the more clever things Pioneer did.
My personal favorite is what they dubbed Both Side Play.
Just as auto reverse cassette recorders came on the scene to save you the trouble of flipping
the tape, Pioneer also developed laserdisc players that can play both sides of the disc.
And the way they go about it is, just so awesome.
Seriously, Both Side Play is my favorite example of forced engineering--I’ll explain what
I mean there but first let’s have a look at a machine with this feature.
This is a Pioneer CLD-D502.
Their model naming scheme, by the way, helps explain what the machine can do.
It wasn’t entirely consistent over the years, but in general the C in CLD means it can also
play audio CDs and CD-Video discs--not video CDs, though.
The D means it plays both sides.
And the 502 is the model number, with higher numbers generally having more features.
For example, the CLD-D702 added extra AV out ports, featured an altered VFD display, and
had better video performance.
A model like the CLD-S201 could only play a single side.
There were also the CLD-M models, which featured a 5 disc CD changer alongside normal laserdisc
operation.
This channel used to have a video featuring one of those machines, however I’ve taken
it down temporarily because I want to re-do that video properly and not in the very rambly
style of the first incarnation.
Stay tuned for its replacement.
Anyway, you might know what’s involved in playing the second side, but for those who
don’t, see if you can guess.
I’ll start this disc on Side A.
[Various mechanical noises]
OK, so it spun the disc
up and is now playing.
But listen to what happens when I switch to Side B.
[More mechanical noises, with a pronounced whirring added]
You probably noticed it stopping the disc, then the motor that moves the tray
in and out did some moving about, and there was a third sound you haven’t heard yet,
along with the disc spinning back up.
Obviously a good deal of stuff just happened, so let’s look inside.
In addition to usually being a little bit taller than a single-sided laserdisc player,
Both Side Play models generally have this protrusion out the back.
This houses the laser turn mechanism.
That’s right, in these machines, the entire laser assembly is moved to the top side of
the disc.
This is some pretty crazy engineering in a number of ways.
So let’s see it in action.
The laser assembly normally sits here and rides along the bottom rails.
But when it needs to read Side B, it travels all the way to the rear of the machine, where
it enters a sort-of ferris wheel like contraption.
This lifts the laser to the top as well as flips it upside down, and then the laser moves
forward and engages with a second set of rails on the top.
The disc stops to reverse direction, as it would otherwise be spinning the wrong way.
Let's look at that in slow motion.
Because why not.
This is no simple feat, as the laser needs to derail itself from the bottom and re-attach
to the top.
It also requires a relatively complex and delicate ribbon cable situation to actually
send power and retrieve signals from the laser head assembly.
But the fact that this was necessary hints to yet another reason laserdisc didn’t achieve
mass market success.
See if someone were interested today in making a CD or DVD player that could read both sides
of a disc --which admittedly isn’t really ever necessary-- almost certainly the cheapest
and simplest way to do it would be to place a second laser assembly on the top, and simply
change which one was being used.
In fact, there were a number of stylized CD changers available that simply had multiple
CD player mechanisms stacked in a tower.
Obviously it was pretty cheap the make a CD player assembly.
But clearly there was something about the laser assembly of a laserdisc player that
made it much more expensive.
And I’m not talking about the rails or the motor that moves it, I mean this guy itself.
If it were easy to make, why not just use two of them?
Why bother with engineering and manufacturing this elaborate mechanism?
I suspect that the analog nature of the laserdisc meant tighter tolerances and higher quality
components were required here.
See, with a digital format, the “clarity” of the signal coming from the laser is pretty
much irrelevant.
So long as a pit can be distinguished from a land, the output would be the same.
In other words, a fuzzy and hard to decipher
[volume diminished with added static sound] one-zero-zero-one-one-one-zero-zero
[static ends and volume returns] means the same thing
to a digital to analog converter as a strong and clear one-zero-zero-one-one-one-zero-zero.
In OTHER other words, the signal to noise ratio is irrelevant in a digital format.
Either the signal is there or it isn’t.
Signal to noise ratio can get really bad before the data is not recoverable.
But since laserdisc was an analog format, the signal to noise ratio did matter.
If the pits become harder to distinguish from the lands, then the picture it produces gets
less clear as well.
I suspect that the laser assemblies of compact disc players could be made much more cheaply
than laserdisc players due to this fundamental advantage of a digital format.
If you look at the list price of a basic CD player made around the same time as this Laserdisc
player, you’ll see that they could be had for about 100 dollars.
This laserdisc player is listed at $459, and the CLD-S201, a single side machine, is listed
at $319.
Now if manufacturers could turn a profit on a CD player at just over $100 dollars, that
laser pickup probably didn’t cost more than $30 or so to make.
Of course, a laserdisc player has much more circuitry and a larger spindle motor than
a CD player, but the way the data is read from the disc is the same.
I’m sure if Pioneer could have figured out how to make an acceptable analog laser pickup
for $30, this mechanism would have been ditched for a second laser permanently attached to
these upper rails.
But that clearly wasn’t possible, as pioneer was forced to keep using similar laser transfer
mechanisms until the end of Laserdisc.
Digital formats were also helped by the implementation of error correction.
A CD player can detect errors and correct them through Cross-interleaved Reed-Solomon
coding, and it can also use interpolation to mask a very large error.
In fact, I have a copy of Lincoln by They Might Be Giants which has a bunch of small
holes in the aluminum layer.
You can hold it to a light and see right through them.
But it still plays fine, as even with chunks of missing data the CD player’s robust error
correction allows it to make it through.
A Laserdisc enjoys this sort of redundancy in its digital soundtrack, but the video has
no such error correction.
A large enough scratch on the disc will be visible, sometimes as a simple black spec.
In a CAV disc, the speck would briefly stay on screen in the same place, but in a CLV
disc, it would dart around the screen.
And then there’s laser rot.
Ah yes, laser rot.
Someone in the comments noted that it’s called disc rot as it has nothing to do with
the laser, which is technically correct, but Laser Rot is the term used when specifically
talking about disc rot occurring on laserdiscs.
The original Discovision manufacturing plants made their discs very sloppily.
It wasn’t uncommon for the aluminum reflective layer to start to oxidize and lose its reflectivity,
likely due to poor adhesive which didn’t seal the discs correctly.
You can forgive them a little though, as they were literally writing the book on how to
make an optical disc.
Oxidation of the aluminum layer would cause a disc to exhibit more and more visual artifacts,
and eventually become unplayable.
This copy of Star Trek the Motion Picture from 1980 exhibits severe laser rot.
You can see that this disc is completely gone just by looking at it.
It should NOT look like that.
But its companion, while not showing physical signs of rot, doesn’t play well at all.
Take a look.
[COMPUTER: Intruder unidentified.
Believe luminescent cloud to be enormous power field surrounding alien vessel...]
[Star Trek theme plays with choppy static and noise...]
[CHEKOV: Photon torpedo load status...]
[UHURA: Transporter system fully repaired…]
Aside from the frequent signal dropouts, the player isn’t able to maintain tracking and
sometimes gets locked reading the same spot.
[You haven’t logged a single star hour in two-and-a-half years.
That plus your unfamiliarrrrrr (disc becomes locked here)]
Most discs don’t rot so badly
that you can simply tell at a glance.
This disc is a true disaster.
Laser rot wasn’t that common, possibly affecting as few as one percent of discs according to
the Laserdisc Database--of course that exists-- but certain factories were notorious for producing
discs that are rotting today.
The DADC plant in Terre Haute, Indiana seems to have been the worst offender, with 1,490
titles from this factory known to have rot.
Including this disc of Fargo, the 21st most commonly reported disc with rot.
[MARGE: OK.
Yeah.
Think I’ll take a drive down there, then.]
[STATE TROOPER: Oh yeah?
Twin cities?]
[NORM: Oh yeah?]
[JERRY: No, Wade, they were real clear.
They said they’d call tomorrow with instructions and it’s gotta be delivered by me alone.]
[WADE: It’s my money, I’ll deliver it.]
Wow, this video got long quickly.
We’re almost done with this saga on laserdisc, and I’ll leave you with this machine.
This is a Pioneer DVL-700.
The D at the beginning means it can also play DVDs.
This is a very early DVD player, from 1997.
As we know, DVD was a huge success, and they continue to sell in large numbers.
Already DVD is as old as Laserdisc was when it died, but DVD shows no signs of dying quite yet.
In the next video, we’ll look at some of Laserdisc’s features that we didn’t get
in the States, and we’ll also see why DVD was able to succeed where Laserdisc failed.
Thanks for watching, I hope you enjoyed the video!
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[NARRATOR: With the advent of three-dimensional computer animation, different looks and styles
have evolved]