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Discussion Starter · #1 ·
can someone please tell me how laser discs compare to dvds in terms of video and audio quality? in terms of resolution?


any help would be appreciated...thanks.
 

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The short version is:

**Video: LD = 425 lines vs DVD ~480 lines, with a big "but"

-> anamorphic DVD packs those lines in the whole screen while some of the LD's lines go to drawing the "black bars" (I only have letterbox LD's).

**Audio: old LD's only had PCM (like CD's), but later LD's had AC-3 just like DVD, with a possible "but"

-> LD's encoded DD @ 384kbs while MOST DVD's are at 448kbs


Bottom Line: while LD's might look OK on good players (I still have a CLD-99), a good DVD master will beat a good LD master on a good machine, especially on large screens (like projectors). The only thing I can really tolerate on my projector is progressive scan DVD and HDTV (via VGA).
 

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Discussion Starter · #3 ·
Thanks for your excellent reply! :)
 

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Quote:
Originally posted by Stanton
The short version is:

**Video: LD = 425 lines vs DVD ~480 lines, with a big "but"

-> anamorphic DVD packs those lines in the whole screen while some of the LD's lines go to drawing the "black bars" (I only have letterbox LD's).

**Audio: old LD's only had PCM (like CD's), but later LD's had AC-3 just like DVD, with a possible "but"

-> LD's encoded DD @ 384kbs while MOST DVD's are at 448kbs


Bottom Line: while LD's might look OK on good players (I still have a CLD-99), a good DVD master will beat a good LD master on a good machine, especially on large screens (like projectors). The only thing I can really tolerate on my projector is progressive scan DVD and HDTV (via VGA).
Excuse me but it is wrong.


For the IMAGE:


The difference is not in the number of horizontal lines but in vertical lines.

Both are NTSC or PAL so both have the same number of video lines.

The difference is the Bandwidth, increasing number of vertical lines (number of pixels by lines if you prefer).

LD : 425(NTSC)/440(PAL)

DVD: 720(NTSC & PAL)


The DVD is the only one to adopt anamorphic enhancement, that means that all the lines are used to present a 16/9(widescreen) image

so when you watch a movie in 1.85 format you only lose a couple of lines, and so on and so forth.

The increase in definition is about 33% above LD

DVD has a digital image stored in MPEG2 files, compression may be visible, but it is well made most of the time, and noise free.

LD image was encoded in composite, so it was noisy and some time very bad, but the THX certified LD were good, see The Lion King or the last Star Wars trilogy or Alien4 or Waterworld.... to know what it is worth.



For the SOUND:


LD was PCM or AC3 FM(Dolby Digital) or DTS(PCM)

The Good thing is for every one of these audio standard, the compression was less than the same thing on DVD.

EX:

Dolby Digital 5.1

LD=640kB/s

DVD=448kB/s


DTS

LD=always full bit rate... 1536kB/s

DVD=sometimes full bit rate but most of the time 768kB/s


PCM

LD=like CD, so 1440kB/s but it had a dynamic that only some DTS track can reproduce, and very rarely !

You can find Dolby Surround and DolbyPro Logic Track tha are really amazing !

DVD= nope, nearly none of the movies have a PCM track.


I have surely forgotten something....


RNO. ;)
 

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Quote:
Originally posted by deus-ex
The difference is not in the number of horizontal lines but in vertical lines.

Both are NTSC or PAL so both have the same number of video lines.

The difference is the Bandwidth, increasing number of vertical lines (number of pixels by lines if you prefer).

LD : 425(NTSC)/440(PAL)

DVD: 720(NTSC & PAL)
720? No, not a chance. 720 is high-definition. DVD is not high-definition; it is 480 vertical lines.

Quote:
The DVD is the only one to adopt anamorphic enhancement, that means that all the lines are used to present a 16/9(widescreen) image

so when you watch a movie in 1.85 format you only lose a couple of lines, and so on and so forth.

The increase in definition is about 33% above LD
You are distorting the numbers. Anamorphic enhancement increases the horizontal resolution by 33%, but not the vertical, which remains the same 480 lines. Thus, the difference between a non-anamorphic laserdisc and an anamorphic DVD is quite visible, but is not the jump that your 33% figure implies.

Quote:


Dolby Digital 5.1

LD=640kB/s
384kBs, actually.

Quote:
DVD=448kB/s
The bit rate on Dolby Digital for DVD is not fixed. It may go up to 448kBs, but is sometimes encoded as low as 120kBs (for some mono tracks, especially on MGM discs). Often it averages about the same as laserdisc.


Also, laserdisc Dolby Digital tracks were never "dumbed down" for better down-conversion to 2-channel stereo as is done to many DVD audio tracks.

Quote:
DTS

LD=always full bit rate... 1536kB/s
It's about 1200, actually (I don't have the exact figure handy at the moment), which is around 3/4 of the potential for "full bit rate" DTS on DVD.

Quote:
DVD=sometimes full bit rate but most of the time 768kB/s
Full bit rate DTS on DVD is all but extinct. Most studios prefer to cram a half bit rate DTS track on the same disc as a DD 5.1 track.


Advantage - laserdisc.

Quote:
Originally posted by Stanton
**Audio: old LD's only had PCM (like CD's), but later LD's had AC-3 just like DVD, with a possible "but"

-> LD's encoded DD @ 384kbs while MOST DVD's are at 448kbs
Not, not most. Some.

Quote:
Bottom Line: while LD's might look OK on good players (I still have a CLD-99), a good DVD master will beat a good LD master on a good machine, especially on large screens (like projectors). The only thing I can really tolerate on my projector is progressive scan DVD and HDTV (via VGA).
What resolution is your projector? You might consider buying a decent scaler. I have a DLP projector at XGA resolution and most laserdiscs are quite watchable. An anamorphic DVD is superior, no denying that, but a well-mastered laserdisc on a good LD player can look pretty darn good.
 

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Video:


In 4:3 frame:


DVD PAL = 576 x 720 = 414'720 pixels


DVD NTSC = 480 x 720 = 345'600 pixels


LD PAL = 576 x 567 = 326'592 pixels


LD NTSC = 480 x 567 = 272'160 pixels



Anamorphic enhancement on DVD provides the full 480 NTSC/576 PAL horizontal lines on in a 16:9 frame while a letterboxed LD or DVD only provide 360 NTSC/432 PAL lines of resolution.


For a 16:9 frame:


Anamorphic DVD (PAL) = 576 x 720 = 414'720 pixels


Anamorphic DVD (NTSC) = 480 x 720 = 345'600 pixels


Non-Anamorphic DVD (PAL) = 432 x 720 = 311'040 pixels


Non-Anamorphic DVD (NTSC) = 360 x 720 = 259'200 pixels


Letterbox LD (PAL) = 432 x 567 = 244'944 pixels


Letterbox LD (NTSC) = 360 x 567 = 204'120 pixels



Also the video information on DVD is stored in YUV while on LD only in composite.



Another advantage is that the video information on DVD can be deinterlaced/processed in the digital domain without any additional conversion since the video information is stored digital.


On LD the video information is analog which means that for deinterlacing/processing the videosignal has to be converted to digital first which deteriorates the quality.



Audio:



DVD


DTS = 754/768kbps or 1508/1536kps


DD 5.1 = 384 or 448


DD 2.0 = between 192kbps and 224kbps


DD 1.0 = between 64kbps and 192kbps


LPCM = 1536 (16bit/48kHz usually)


The encoding of DD 1.0 and 2.0 tracks actually varies.

The R2 version of The Thomas Crown Affair has the mono track encoded at 320kbps or the french version of Heavenly Creatures has its DD 2.0 track encoded at 224kbps.


LD:


DTS: = 1411kbps


DD 5.1 = 384kbps


LPCM = 1411kbps (16bit/44.1kHz)


Analog FM stereo



640kbps ist the maximum Dolby Digital can be encoded at. There has however not been a consumer accessibly medium (that I know of) that had a DD track encoded at this rate.


The max. the DVD format allows is 448kbps


The max. the LD format allows is 384kbps


On D-Theater D-VHS the DD tracks are actually encoded at 576kbps. I don't know if the D-VHS format would be capable of the full 640kbps?
 

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Quote:
Originally posted by Josh Z

720? No, not a chance. 720 is high-definition. DVD is not high-definition; it is 480 vertical lines.

Let's be very sharp.

The image is made of video lines, giving the frequency of 15.6kHz.

NTSC has 525/480 of those lines whatever is the support device

PAL has 625/576 of those lines whatever is the support device


The difference between all the older formats is the horizontal resolution, the # of mHz that provide the definition.

For DVD, it is 6.75mHz, not more.

For LD, it is less than that.

So LD can't hold as many "pixels" by line as DVD.

So LD NTSC is 425 pixels wide and DVD NTSC is 720.

And DVD PAL is 720 too instead of the LD PAL that is 440.


I am not wrong, please read along and you will see it.

Quote:
You are distorting the numbers. Anamorphic enhancement increases the horizontal resolution by 33%, but not the vertical, which remains the same 480 lines. Thus, the difference between a non-anamorphic laserdisc and an anamorphic DVD is quite visible, but is not the jump that your 33% figure implies.
It is not that simple, maintaining a format of 1.33 LD means that it can handle 1.85 format by adding black bars on the top and the bottom of the image.

Adding is not the right word as the image is STORED like that.

So draw it on a paper and you will see that you waste 28% of the image in black bars.

Try with other format if you want.


On DVD:

The image can be store in ANAMORPHIC.

That means that whatever is the format of the movie, the whole resolution is used to store the image.

During the decompression, the chipset is reformatting the image to the aspect ratio you ask, widescreen is the best, and add black bars to fill the screen.


......



Roland Wandinger, I love you :D


But are you sur of your LD resolutions ?

Because LD is told to do 425 pix wide fot NTSC and 440 pix wide for PAL. Really !
 

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Quote:
But are you sur of your LD resolutions ?

Because LD is told to do 425 pix wide fot NTSC and 440 pix wide for PAL. Really !
The 425 referrd to as the horizontal resolution of LD is actually 425pph (per picture hight).


This means in a 3:3 frame the resolution would be 480x425.

The format however is 4:3 which means that the 425 have to be multiplied by 1.33333 which comes to 567 "pixels" per line.


I have also noticed that the horizontal resolution of PAL LDs was always indicated with 440? I don't know why 440, I have been under the impression that a PAL LD also has 425pph.


In "DVD Demystified" PAL LDs are indicated to have 425pph also?


Quote:
Let's be very sharp.

The image is made of video lines, giving the frequency of 15.6kHz.
I think you mixing up things. ;) The number 15.6kHz has nothing to do with horizontal resolution or bandwidth only with the number of horizontal lines times the refresh rate.


In interlaced that is:


PAL = 625 H-Lines x 50 fields = 15.625 kHz


NTSC = 525 H-Lines x 29.97 fields = 15.734 kHz
 

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Quote:
I think you mixing up things. The number 15.6kHz has nothing to do with horizontal resolution or bandwidth only with the number of horizontal lines times the refresh rate.
That was exactly what i meant.

That the number of lines never change when you re talking of one standard.


Actually it is 59.94 (29.97*2) for NTSC ... ;)

or 25 for PAL...


You choose :D


So to finish about that thing, if the video compression is well made, the DVD is FAR superior to the same well done LD, granted to its anamorphic capability, that is the main improvement.


Are we ok Roland ?


Do you speak french Roland ?

Where do you live ?

We could meet, i will be please to do so !
 

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Quote:
Actually it is 59.94 (29.97*2) for NTSC ...
Only on videobased signals where there are 59.94 interlaced fields (not frames).

Quote:
So to finish about that thing, if the video compression is well made, the DVD is FAR superior to the same well done LD, granted to its anamorphic capability, that is the main improvement.


Are we ok Roland ?
Yes! ;)


Quote:
Do you speak french Roland ?

Where do you live ?

We could meet, i will be please to do so !
Sorry, I don't speak french. They tried to teach me but it didn't stick! ;)


I live near Zürich.
 

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Quote:
Originally posted by deus-ex
The difference between all the older formats is the horizontal resolution, the # of mHz that provide the definition.

For DVD, it is 6.75mHz, not more.

For LD, it is less than that.

So LD can't hold as many "pixels" by line as DVD.

So LD NTSC is 425 pixels wide and DVD NTSC is 720.

And DVD PAL is 720 too instead of the LD PAL that is 440.
Again, you are distorting the numbers. First off, as you well know, laserdisc is an analog medium and cannot be measured in pixels. Secondly, in your first post you claimed that DVD has 720 lines of resolution, but to back that up you instead quote the pixel count.


Taken directly from the DVD FAQ:

Quote:
Picture dimensions are max 720x480 (for 525/60 NTSC display) or 720x576 (for 625/50 PAL/SECAM display). Pictures are subsampled from 4:2:2 ITU-R BT.601 down to 4:2:0, allocating an average of 12 bits/pixel in Y'CbCr format. (Color depth is 24 bits, since color samples are shared across 4 pixels.) DVD pixels are not square. The uncompressed source is 124.416 Mbps for video source (720x480x12x30 or 720x576x12x25), or either 99.533 or 119.439 Mbps for film source (720x480x12x24 or 720x576x12x24). In analog output terms, lines of horizontal resolution is usually around 500, but can go up to 540(see 3.4.1). Typical luma frequency response maintains full amplitude to between 5.0 and 5.5 MHz. This is below the 6.75 MHz native frequency of the MPEG-2 digital signal (in other words, most players fall short of reproducing the full quality of DVD). Chroma frequency response is half that of luma.
I would add that the "usually around 500" is actually mitigated in real world terms by the fact that many DVDs are run through high-pass filtering to reduce compression artifacting, reducing the practical resolution to around 480 lines.


When you throw in the magic number 720, it sounds like, "Wow that's an amazing jump!" because you are misleading the reader into equating the number 720 with the HD resolution of 720p, which in that case is an actual measure of lines of resolution. In reality, that is not the case at all for DVD.


DVD does not measure 720 lines of resolution. That is an HD figure. DVD is not an HD format.

Quote:
It is not that simple, maintaining a format of 1.33 LD means that it can handle 1.85 format by adding black bars on the top and the bottom of the image.

Adding is not the right word as the image is STORED like that.

So draw it on a paper and you will see that you waste 28% of the image in black bars.

Try with other format if you want.


On DVD:

The image can be store in ANAMORPHIC.

That means that whatever is the format of the movie, the whole resolution is used to store the image.

During the decompression, the chipset is reformatting the image to the aspect ratio you ask, widescreen is the best, and add black bars to fill the screen.
Yes, I know that, however anamorphic enhancement only increases the resolution in one direction, not in both directions. You cannot say that DVD is 33% sharper than laserdisc when it is only 33% sharper in one direction.


Don't get me wrong, I know that an anamorphic DVD is superior to a non-anamorphic laserdisc. I also know that with the right equipment a laserdisc can look damn good in its own right.


They are both good formats. They both have their own strengths and weaknesses (you'll never see a compression artifact on a laserdisc, and I don't care what that the numbers say because laserdisc audio almost always sounds superior to DVD audio). I fully enjoy both formats for what they are and I encourage others to do the same.
 

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Hello Josh,


Let be simple.


LD and DVD have the same number of lines, exactly the same as they share the same video standard.

The difference is somewhere else.

The difference is in details on each line, DVD can handle 720 pix on each line, LD can only do 567 pix on each line.


This and the anamorphic are the only change for the resolution.

DVD is not HD, DVD is pure PAL or NTSC, LD was like SVHS or VHS, a reduced detailled NTSC or PAL, but with the same number of lines.


are we OK now ?


:)
 

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Quote:
You cannot say that DVD is 33% sharper than laserdisc when it is only 33% sharper in one direction.
Actually one can say that.

Quote:
and I don't care what that the numbers say because laserdisc audio almost always sounds superior to DVD audio
It's true, many DD and DTS tracks on LDs did sound better/fuller than their DVD counterpart. This however was not due to the format themselves but rather to the soundmix used (cooking down for 2 channel playback etc.)


I much prefer the LPCM soundtrack on LD for old mono movies compared to the 192kbps DD on DVD.
 

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On DVD:

The image can be store in ANAMORPHIC.




Well, you CAN store in anamorphic on laserdisc too.




I'm with Josh on this. A good/great LD with a great LD player will give a great picture! I great LD with a recent movie will look better than many DVD's with older movies, can't you guys see those DVD's either?


I have seen rather many LD's that are better than the DVD IMHO, because of my zero tolerance of compression artifact's. I also think that LD sound better most of the time. But DVD ARE a better format, but not always used in the best way.
 

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The point was not to say which one we prefer, or which one was the "best"...


The question is Resolution.


one last link for every one, i think you know this page, but it set every thing we talked about DVD.

http://www.cybertheater.com/Tech_Rep...projector.html


see you !
 

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Ack! More arguing fuel!


Doesn't LD actually predate CDs? If that't true LD was a fantastic technology for it's time. I don't think anyone would disagree, though, that when both formats are at their best that anyone would willfully choose LD.


Don't most if not all DVDs have a 2 channel PCM track too? I'm not positive about it, though. Remember too that even uncompressed pro-logic does NOT have full range center or rear matrixed channels. And that matrixed channels, no matter how good your processor, will have some bleeding into other channels, which for you hard-core audiophiles is an absolute no-no.


The one nice thing about LD is that there are some movies/events on LD that you'll probably never see on DVD.


Before anyone pounces on me, I'd like to say that I have a laserdisc player and about 100 movies and concerts on LD, AND I still think they're pretty darn cool.


Mike
 

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True....


I wouldn't choose LD for the 2 channel PCM, Dolby Pro Logic is past.

I like DTS, and the image quality of the new DVD from Fox and Warner.


I still have some 12/15 LDs..


Star Wars definitive collection

Indiana Jones,

The Lion King

Aladdin


some others...


Mainly what haven't been released yet on DVD.


But LD once processed via PC and Dscaler is really good !
 

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Quote:
Originally posted by otzdig
Doesn't LD actually predate CDs?
Yes, laserdiscs were first released in 1978. They originally had only analog sound. Digital sound was introduced in the mid-80s around the time that CDs came out.

Quote:
Don't most if not all DVDs have a 2 channel PCM track too? I'm not positive about it, though.
No, not at all. PCM on DVD is rare to the point of almost non-existence.


Most DVDs that offer the choice of a 2-channel sound mix (rather than just downmixing the 5.1 track) do so with a Dolby Digital 2.0 track.
 
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