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Posted by Biz on 01/21/06 04:50
Start here:
http://www.dvddemystified.com/dvdfaq.html#3.6.2
According to this, all DVD-V audio is 48khz, or higher, 44.1 khz is not
allowed in the DVD-V spec....
Sampling rate shouldnt affect sync.
If the sync is off during the capture, due to dropped frames etc....and its
not exactly consistent, like 450ms behind or ahead throughout the entire
clip, then there is nothing you can do to fix it, besides recapture. But
you said your preview didnt have sync issues, so I took that to mean your
source didnt have sync issues...
People post here and other places all the time about having sync issues when
creating their own dvds....many claim their source material is perfectly
insync, others are converting from say xvid/divx avi with vbr audio which
usually causes trouble....
I still say start with a small sample project, say 5-10 minutes of video
with audio, and go through the whole process step by step. These all in one
converters are mostly crap, you will never find the problem using one of
those packages either...
Its a pretty simple process when you look at the bare steps:
1. Start with your original source.
2. Seperate the audio stream(s)from the video stream(s)-called demuxing.
Here s a great check step. If the reported video length and the reported
audio length do not exaclty match then you already have a problem....
3. Convert the video to an appropriate resolution MPEG-1 or MPEG-2 based on
your source...
4. Convert the audio to 48khz, and either make it LPCM, AC-3, DTS, or MPEG
audio, again, best to make the choice based on the tools you have, what you
plan to play it on, and the quality of the source material...
5. Combine the results of steps 3 and 4. Called muxing, multiplexing,
etc....
6. Use your preferred DVD authoring software, add the result from step 5,
many packages allow you to add steps 3 and 4 so you dont need to do 5 on
your own, ANY good package will analyze it and say it needs no changes to be
added as is...Here is where you also create menus, chapters...etc....
7. Create the DVD, you should end up with a VIDEO_TS folder
8. Burn it
"Javaholics" <crbjr@earthlink.net> wrote in message
news:ZsfAf.10644$ZA2.9394@newsread1.news.atl.earthlink.net...
> My sound is behind the visual.
>
> Biz...are you saying that the only way a DVD can playback audio is if it
is
> 48 kHz or is this an amount you want for the best audio playback? Said
> differently, will lesser kHz work but just not sound as good?
>
> Do different sampling rates affect sync or not...I'm still confused? If
> not, then do you have other suggestions on where I might encounter sync
> problems?
>
> You mention that some programs don't convert it properly...is this a
> condition that can be witnessed or determined by the user or just an
> inherent problem known to exist in certain products?
>
> If the program doesn't convert it properly, then does this mean that the
> expected results could be considerably less or more than the value
desired?
>
> Can the capturing process (VHS to hard drive) have anything to do with my
> sync problems or is it more likely the software's ability to convert this
> information during the making/burning process?
>
> If it is determined to be the program that is at fault, then do you have
> recommendations on other software in the less than $200 price range that
> might net me a better finished product?
>
> Thanks
>
> "Biz" <spamoff@sbcglobal.net> wrote in message
> news:i8dAf.15400$Yu.3762@newssvr27.news.prodigy.net...
> >
> > "Rick Merrill" <rickZERODOTmerrill@NOSPAMgmail.com> wrote in message
> > news:KeOdnanE3Y-Cx0zeRVn-rw@comcast.com...
> >> Javaholics wrote:
> >> > It is NTSC...I converted two VHS tapes to MPEG-2 at 29.97fps. A
> >> > preview
> > of
> >> > final product prior to burning, netted no discernable problems and
> > appeared
> >> > as expected. Only after the burning process, when I played the DVD,
> >> > did
> > I
> >> > then notice the sync problem.
> >>
> >> Playing a DVD requires audio at a 41 KHz sampling rate, BUT MPEG-2 can
> >> use 32 or 41 or (most likely) 48 KHz sampling rate. If that's the
> >> problem then your sound should be BEHIND the video. Is your sound
> >> ahead or behind the visual?
> >>
> >
> > Close....Audio on a DVD must be 48khz, but mpeg can use several
different
> > sampling rates...The sampling rate should not affect teh sync, however
> > some
> > programs dont convert it properly, if its not already 48khz...
> >
> >
>
>
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