I am using Roxio DVD builder to capture DV and burn a CD. I just recorded
1:45 and it says it needs 5.6 Gigs. I thought a DVD should do 2 hours in
about 4.6 Gigs. What am I doing wrong?

Danny Deger

"Danny Deger" <(E-Mail Removed)> wrote in message
news:bgv33r$t18ch$(E-Mail Removed)...
> I am using Roxio DVD builder to capture DV and burn a CD. I just recorded
> 1:45 and it says it needs 5.6 Gigs. I thought a DVD should do 2 hours in
> about 4.6 Gigs. What am I doing wrong?
>
> Danny Deger

Everything depends on the software you're using to encode the mpeg stream,
as well as the bit-rate that you set. I just finished a 2:15 minute DVD,
encoded at 4200, and it turned out just fine.

>
>

Try to decrease the sound bit rate up to 92kb/s stereo. It
will give you a smaller mpeg file size.
>-----Original Message-----
>Hello Danny,
>
>A DVD-R is single-sided, single-layer. This means that
it can hold 4.37 gb
>of data, or 4.7 billion bytes. I'm not familiar with the
Roxio software,
>but a 1:45 movie will need an average bitrate of about
4200 kbit/s.
>
>Hope this helps!
>
>Barry Rosenstock
>Anchor Digital Inc.
>The Leader in Interactive DVD Production
>http://www.anchordigital.com
>
>> I am using Roxio DVD builder to capture DV and burn a
CD. I just recorded
>> 1:45 and it says it needs 5.6 Gigs. I thought a DVD
should do 2 hours in
>> about 4.6 Gigs. What am I doing wrong?
>>
>> Danny Deger
>>
>>
>
>
>.
>

"Irn Mdn" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed)...
> coolmercy <(E-Mail Removed)> wrote in message
news:<(E-Mail Removed)>...
> > On Thu, 7 Aug 2003 20:49:06 -0700, "PTRAVEL" <(E-Mail Removed)>
> > wrote:
> >
> > >
> > >"Danny Deger" <(E-Mail Removed)> wrote in message
> > >news:bgv33r$t18ch$(E-Mail Removed)...
> > >> I am using Roxio DVD builder to capture DV and burn a CD. I just
recorded
> > >> 1:45 and it says it needs 5.6 Gigs. I thought a DVD should do 2
hours in
> > >> about 4.6 Gigs. What am I doing wrong?
> > >>
> > >> Danny Deger
> I routinely fit 3+hours of ballgames on a DVD-R MPG-2 320x240@3000kps VBR
> encoded using TMPEG with some filters (noise/block reduction)
> The qulity is very satisfactory (similar to SP VHS).

Thanks everyone. I have just tried TMPGEnc and found the feature of setting
the video bit rate: however, the audio bit rate was set to 1536 and grayed
out so I couldn't adjust it. I selected extra and found the same: audio
options all grayed out. Any ideas.

Also, I couldn't find in Roxio 6 how to get it to combine a video and audio
file that are separate into a single DVD. I have Ulead and Roxio. Maybe I
need to get DVDlab.

I did find a feature in Roxio 6 DVD Builder to have it calculate how much
compression to use to make the file fit on a DVD. Obviously not as much
control as I get with TMPGEnc, but I am letting it encode as we speak. I
would much prefer to cut down on audio quality than video. All I have is
voice -- it doesn't take a lot of bandwidth to do voice.

Danny Deger

On Fri, 8 Aug 2003 17:47:51 -0500, "Danny Deger"
<(E-Mail Removed)> wrote:

>Thanks everyone. I have just tried TMPGEnc and found the feature of setting
>the video bit rate: however, the audio bit rate was set to 1536 and grayed
>out so I couldn't adjust it. I selected extra and found the same: audio
>options all grayed out. Any ideas.

1536 is for PCM audio. Your only other two options in NTSC are AC3
(dolby digital) and DTS ($$$$).

Some DVD authoring programs doesn't support AC3 audio, which includes
yours apparently.

>Also, I couldn't find in Roxio 6 how to get it to combine a video and audio
>file that are separate into a single DVD. I have Ulead and Roxio. Maybe I
>need to get DVDlab.

I'm not familiar with your software, sorry.

>I did find a feature in Roxio 6 DVD Builder to have it calculate how much
>compression to use to make the file fit on a DVD. Obviously not as much
>control as I get with TMPGEnc, but I am letting it encode as we speak. I
>would much prefer to cut down on audio quality than video. All I have is
>voice -- it doesn't take a lot of bandwidth to do voice.
>
>Danny Deger

--
http://ripperd2.dhs.org

On Thu, 7 Aug 2003 21:49:29 -0500, "Danny Deger" <(E-Mail Removed)>
wrote:

>I am using Roxio DVD builder to capture DV and burn a CD. I just recorded
>1:45 and it says it needs 5.6 Gigs. I thought a DVD should do 2 hours in
>about 4.6 Gigs. What am I doing wrong?

You might want to consider getting a decent MPEG-2 encoder that has a decent
set of options, such as TMPGEnc or CinemaCraft Basic (both relatively cheap,
$40-50 each). A DVD will hold about 4.38GB (4.7 billion bytes, or "marketing
gigabytes" in the hard drive and optical drive world). How much _time_ will
fit onto a DVD-Video disc will be determined by the mean bitrate of the
video. Apparently Roxio's MPEG-2 encoder is using a high enough bitrate that
you're limited to a fairly short amount of video on a disc.

If you've got the budget, you might also consider getting Vegas+DVD for its
AC3 encoder. AFAIK, it's still the cheapest AC3 encoder on the market
(though now that they've broken through that barrier, others are bound to
follow), along with being a darn fine NLE. Compressing your audio to AC3
format will save you a good deal of space, which lets you fit more video on a
disc at a higher quality level.

--
Erik Harris n$wsr$ader@$harrishom$.com
AIM: KngFuJoe http://www.eharrishome.com
Chinese-Indonesian MA Club http://www.eharrishome.com/cimac/

The above email address is obfuscated to try to prevent SPAM.
Replace each dollar sign with an "e" for the correct address.

On Fri, 8 Aug 2003 22:23:37 -0500, "Danny Deger" <(E-Mail Removed)>
wrote:

>Does AC3 take less space than the MPEG-1 I get with TMPGEnc? Will MPEG-1
>audio play on a DVD player?

AC3 and MPEG-1 both support multiple bitrates. However, The NTSC DVD format
requires that a DVD have at least one audio track that's either PCM
(uncompressed) or AC3. The PAL DVD format requires that a DVD have at least
one audio track that's PCM, AC3, or MPEG-2 audio. Neither spec supports
MPEG-1 audio. You _might_ find that some players will work with MPEG-1 audio
on a DVD (since most will play VCD's, which use MPEG-1 video and audio), but
it'd be a gamble, and you'd also have a hard time finding a DVD authoring
program that'll support MPEG-1 audio on a DVD-Video project.

>On bit rate on the video, what degrades as a select a lower rate. On
>TMPGEnc, it shows the same resolution and the same refresh rate. What
>happens to the video as I select a lower rate?

Compression doesn't change your resolution or your frame rate. It changes
the quality of what's there.

The short answer is that you'll see blocking artifacts and noise at edges as
you reduce the bitrate.

The longer answer involves a basic explanation of how video compression
works. In a nutshell, MPEG-2 creates a number of I-frames, every X frames
(usually about 15, which I think it the largest I-frame spacing allowed on
DVD video). That I-Frame is a compressed picture. The color data in the
picture is downsampled by 2 in each direction (so you have a 720x480 black
and white picture with 360x240 color information on it), and the luma (B&W)
and luma (color) channels are DCT compressed. They're broken into 8x8 blocks
and transformed with a Discrete Cosine Transform (DCT), which results in an
image that has better energy compaction (the "most important" stuff is in the
beginning of the data stream, and the less noticeable stuff is at the end).
Then it throws away some of the less significant bits. So far, we've
basically covered how JPEG works on images, too (Except that with JPEG, the
chroma downsampling is optional. With MPEG-2-for-DVD, it's not). The
up-to-14 frames in between each I-Frame are filled with P and B frames. P
frames are "predicted" frames from the previous frames. B frames are
"bidirectionally predicted" frames based on the frames before and after it
(so they're more efficient, but require knowledge of future frames, and take
longer to generate). I don't know MPEG well enough to know exactly how the
predicted frames are generated. I expect that it's a basic interpolated
image from the previous few frames, and a compressed representation of a
difference image - the data needed to go from the prediction to the actual
picture (because if 14/15 frames were _only_ predicted, without correction
factors, they'd look terrible).

Okay, so that's a bit of a large nutshell, but there you have it.

--
Erik Harris n$wsr$ader@$harrishom$.com
AIM: KngFuJoe http://www.eharrishome.com
Chinese-Indonesian MA Club http://www.eharrishome.com/cimac/

The above email address is obfuscated to try to prevent SPAM.
Replace each dollar sign with an "e" for the correct address.

> Does AC3 take less space than the MPEG-1 I get with TMPGEnc? Will MPEG-1
> audio play on a DVD player?

MPEG-1 Layer II audio is not guaranteed to work in all DVD players.
You have two options: uncompressed (PCM) audio, which is 1500
kbit/sec, or AC3 audio, which can squish that down to 300-400 kbit/sec
with virtually no noticeable loss in quality. (AC3 encoders tend to be
expensive though)

> On bit rate on the video, what degrades as a select a lower rate. On
> TMPGEnc, it shows the same resolution and the same refresh rate. What
> happens to the video as I select a lower rate?

As the bitrate gets lower, the video will look more "blocky", because
the MPEG video encoder must throw away more information. If you want
to see what this looks like, try encoding an NTSC video clip at <1
Mbit/sec (...or watch any channel on a digital cable TV service
*rimshot*

Regards,
Dan