Posted by Bill Vermillion on 02/11/07 19:55

In article <45BF6FC8.8DB78C80@nospam.com>,
Ted <nospamforted@nospam.com> wrote:
>
>
>Doug Jacobs wrote:
>>
>> In alt.video.dvd Ted <nospamforted@nospam.com> wrote:
>>
>> > Yes there was. It wasn't much of a fight because no one in their right
>> > mind wanted DIVX to win that war, but it there was a question of whether
>> > or not the studios would successfully cram DIVX down the throat of
>> > consumers. mInstead they successfully crammed DVDs down our throats, as
>> > many a laserdisc enthusiast will tell you...
>>
>> Divx came out too late to be a serious threat to DVD. DVD had already
>> started to accelerate in the market when Divx showed up abruptly one
>> Christmas.
>
>I was still reading the LD group at the time, and there was continuing
>chatter about the format war. DIVX was largely hated more deeply than DVDs
>
>>
>> Problem is, although the DVD players and DVDs were more expensive than
>> Divx players/discs, the extra cost was easily justified.
>>
>> As for LD vs. DVD, doesn't DVD still win out because of higher resolution
>> video and better audio? Or is this just a matter of capacity != format,
>> meaning you could concievably use LD to hold a DVD-quality movie - it's
>> just that the studios decided to move on to DVD?
>
>More than anything else, DVD won out by weight and size. Laserdiscs are
>incredibly heavy and take up huge amounts of space. The size also
>probably led to a minimum cost relating to shipping weight/shelf space
>that is substantially higher than for DVDs; DVDs were almost immediately
>cheaper than LDs. As LD players also need to cope with that weight, they
>themselves need to be similarly large, and that almost certainly leads
>to increased cost as well.

>There are certain other issues with laserdisc that DVD avoids; disc rot,
>cross talk, and disc flipping among them. Many early DVDs (and lots of
>cheaply done current DVDs) had lots of digital compression artifacts
>tho, and LD avoids that.

>Laserdisc is supposedly theoretically analog; however, it also was made
>using pits and lands, meaning I don't understand how the hell it's
>supposed to be analog; it is at the very least not digitally compressed.
>In theory, if it is truly analog, the underlying video information could
>be far more exact than on any existing digital medium. But even if
>theoretically true, it doesn't happen in practice (think of the audio
>fidelity of an analog meduium like wax cylinders compared to a CD;
>analog isn['t always better). The video on LDs is also composite, and
>while comb filters can improve this issue, DVD avoids it entirely.
>General experience of laserdisc quality could have been improved with
>continually improving player technology, but LD had some problems and
>had had a successful but never breakthrough 20 year run.

An LD signal starts as an FM video signal. Then the tops and
bottoms of the video signal are cut out - to leave only the middle
section of the wave - so it looks somewhat squarish. This is what
is put on the disk. Then when the pulses are read back they are
filtered and the original FM video signal is recovered.

It's definatetly not intuitive. And to have an LD better than DVD
you'd have to expand the bandwidth of the video signal - which sort
of limits what you'd be able to play it upon to get that
improvement, plus you'd have to cut the time of any video
to be able to fit the additional analog information onto the disk.

And as to analog being more exact than digital - digital has finite
bounds - as you have to filter the content. Analog can be expanded
- however every little bit of bandwidth you gain in analog costs a
lot. Every component in an analog chain can contribute to
1)noise, 2) distortion, 3) no-linearity and 4) the artifacts
of the medium upon which it is stored.

The old rule of thumb in audio was the last 5% of improvement was
95% of the cost.

And cylinder records were truly accoustic devices with no
electronics involved anywhere. You comparison would need to be
made with electreically recorded records [ 78's after the late
1920s, 45's and LPs.

Bill
--
Bill Vermillion - bv @ wjv . com

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