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DVD 2 disc vs. DVD 1 disc? Confused

 
 
jayembee
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      09-26-2003
http://www.velocityreviews.com/forums/(E-Mail Removed) (Wootikus) wrote:

> Thanks for all the response. I'm still a bit confused.
>
> How many gigs can a single layer hold?
> How many gigs can a double layer hold?
> Is double layer the same as DVD-9?


There are 4 basic "formats" for DVDs:

(1) DVD-5, which holds around 5 gigs, and is single-sided
and single-layered.

(2) DVD-9, which holds around 9 gigs, and is single-sided
and double-layered.

(3) DVD-10, which holds around 10 gigs, and is double-sided
and single-layered.

(4) DVD-18, which holds around 18 gigs, and is double sided
and double-layered. Quality control in manufacturing is still
problematic with these, which is why you don't see them very
often.

-- jayembee
 
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Sydney Assbasket
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      09-26-2003
>> Speaking of which, this has probably been discussed in the past but I
>> never knew about it until I bought the movie last night - why the heck
>> is "Gangs of New York" spread out across two discs? I know there's a
>> lot of extras on here, but geez, couldn't they have fit all the extras
>> on the second disc?

>
>The DTS track eats up a lot of the available bit space.
>


Each disc contains some extras, so they probably could have put the movie on
one disc and the extras on the other without splitting the film.

Remove "moc" to reply.


Whoever says "Nothing is impossible" has never tried to slam a
revolving door.
- Willy Walker
 
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Wootikus
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      09-27-2003
> There are 4 basic "formats" for DVDs:
>
> (1) DVD-5, which holds around 5 gigs, and is single-sided
> and single-layered.
>
> (2) DVD-9, which holds around 9 gigs, and is single-sided
> and double-layered.


Thanks for the reply. This helps a lot. Why is it that the older
version of Seven is on 2 DVDs? Its running time is just 2 hours and 7
minutes. Shouldn't this fit nicely on just one side?

Another question I have is, there's a couple of movies I saw in the
store that are 3 hours long and yet they got it fit in just one DVD.
Did they just compressed it to the point where quality would suffer?
How do I check up on this? Someone suggested to me to play the DVD
using PowerDVD and look at the Mbps.
 
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Dan P.
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      09-27-2003
Back when DVD was first introduced, they advertised that a single-layer DVD
could hold 130 minutes of video/audio. So a dual-layer DVD could easily
hold 3 hours.

But when you up the Mbps (video quality) or add a DTS soundtrack, or add
multiple DD5.1 soundtracks, or just add a bunch of special features, it
might not fit.

On my DVD player, you can view the Mbps, so maybe your player can do the
same thing. Check the manual.


Dan


 
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Douglas Bailey
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      09-27-2003
Wootikus <(E-Mail Removed)> wrote:

> Why is it that the older version of Seven is on 2 DVDs?


Two (single-layered) sides of the same DVD, actually.


> Its running time is just 2 hours and 7 minutes. Shouldn't this fit nicely
> on just one side?


It depends on the movie: not every 127-minute film will compress to the
same extent. The compressionist may have had to use higher-than-usual
bit-rates to produce an acceptable image (perhaps because _Se7en_ is so
dark? I'm not sure).

_The Godfather Part II_ was split over two discs for what I believe
were similar reasons.

doug

--

---------------Douglas Bailey ((E-Mail Removed))---------------
I can't see the lines I used to think I could read between...
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Erik Harris
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      09-28-2003
On 26 Sep 2003 18:00:56 -0700, (E-Mail Removed) (Wootikus) wrote:

>> There are 4 basic "formats" for DVDs:
>>
>> (1) DVD-5, which holds around 5 gigs, and is single-sided
>> and single-layered.
>>
>> (2) DVD-9, which holds around 9 gigs, and is single-sided
>> and double-layered.

>
>Thanks for the reply. This helps a lot. Why is it that the older
>version of Seven is on 2 DVDs? Its running time is just 2 hours and 7
>minutes. Shouldn't this fit nicely on just one side?


Even if it was encoded at a bitrate very near the DVD standard's maximum
(9.8Mbps or there-about), 2:07 should fit on a single dual layer disc. And
IMHO, there's no excuse for releasing a movie on two single layer discs,
unless it was released before dual layer technology was available (though
wasn't it available right from the start?).

>Another question I have is, there's a couple of movies I saw in the
>store that are 3 hours long and yet they got it fit in just one DVD.
>Did they just compressed it to the point where quality would suffer?


That's hard to answer. What is "the point where quality would suffer"? That
depends on the content of the film and how well it was encoded. A 3 hour
movie should fit onto a dual layer disc at very good quality if it's encoded
well. There wouldn't be room for much else, though.

>How do I check up on this? Someone suggested to me to play the DVD
>using PowerDVD and look at the Mbps.


I believe PowerDVD only lists the maximum bitrate - since most discs are
encoded at a variable bitrate, that maximum will always be 9.8Mbps, even if
it's never reached. You'd need a DVD player with a realtime bitrate monitor
(many of them have it). But even that won't tell you if it's compressed "to
the point where quality would suffer." To judge that, you need a good
monitor and a good pair of eyes (and a brain that knows how to use those good
eyes to look for compression artifacts).

A trained eye will find _some_ compression artifacts even on very well
encoded DVDs, making it even harder to answet a question about "the point
where quality would suffer." Technically, that point is _always_ reached
with DVDs, because MPEG-2 is a lossy compression format even at its highest
quality levels (for one thing, the version of the MPEG-2 standard used on
DVDs requires chroma subsampling. If you have any DVD's with hard edges that
are in red, look at those edges. They will look like crap, because reds
generally suffer most noticeably from chroma subsampling - one example is the
extras in the new Alias box set. Most of the titles were done red on black,
which is a very poor choice when DVD is the intended medium).

--
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AIM: KngFuJoe http://www.eharrishome.com
Chinese-Indonesian MA Club http://www.eharrishome.com/cimac/

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Steve(JazzHunter)
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      09-28-2003
On Sun, 28 Sep 2003 00:17:56 -0400, Erik Harris
<n$wsr$ader@$harrishom$.com> wrote:

>On 26 Sep 2003 18:00:56 -0700, (E-Mail Removed) (Wootikus) wrote:
>
>>> There are 4 basic "formats" for DVDs:
>>>
>>> (1) DVD-5, which holds around 5 gigs, and is single-sided
>>> and single-layered.
>>>
>>> (2) DVD-9, which holds around 9 gigs, and is single-sided
>>> and double-layered.

>>
>>Thanks for the reply. This helps a lot. Why is it that the older
>>version of Seven is on 2 DVDs? Its running time is just 2 hours and 7
>>minutes. Shouldn't this fit nicely on just one side?

>
>Even if it was encoded at a bitrate very near the DVD standard's maximum
>(9.8Mbps or there-about), 2:07 should fit on a single dual layer disc. And
>IMHO, there's no excuse for releasing a movie on two single layer discs,
>unless it was released before dual layer technology was available (though
>wasn't it available right from the start?).
>
>>Another question I have is, there's a couple of movies I saw in the
>>store that are 3 hours long and yet they got it fit in just one DVD.
>>Did they just compressed it to the point where quality would suffer?

>
>That's hard to answer. What is "the point where quality would suffer"? That
>depends on the content of the film and how well it was encoded. A 3 hour
>movie should fit onto a dual layer disc at very good quality if it's encoded
>well. There wouldn't be room for much else, though.
>
>>How do I check up on this? Someone suggested to me to play the DVD
>>using PowerDVD and look at the Mbps.

>
>I believe PowerDVD only lists the maximum bitrate - since most discs are
>encoded at a variable bitrate, that maximum will always be 9.8Mbps,


Nope, PowerDVD shows the current average bitrate, just like the
hardware players with bitrate indicators. It's a good indicator of
the amount of compression,

. Steve .
> even if
>it's never reached. You'd need a DVD player with a realtime bitrate monitor
>(many of them have it). But even that won't tell you if it's compressed "to
>the point where quality would suffer." To judge that, you need a good
>monitor and a good pair of eyes (and a brain that knows how to use those good
>eyes to look for compression artifacts).
>
>A trained eye will find _some_ compression artifacts even on very well
>encoded DVDs, making it even harder to answet a question about "the point
>where quality would suffer." Technically, that point is _always_ reached
>with DVDs, because MPEG-2 is a lossy compression format even at its highest
>quality levels (for one thing, the version of the MPEG-2 standard used on
>DVDs requires chroma subsampling. If you have any DVD's with hard edges that
>are in red, look at those edges. They will look like crap, because reds
>generally suffer most noticeably from chroma subsampling - one example is the
>extras in the new Alias box set. Most of the titles were done red on black,
>which is a very poor choice when DVD is the intended medium).


 
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