Tech Support > Computer Hardware > Desktops > Troubleshooting jerky playback
Troubleshooting jerky playback
Posted by Mitch@hotmail.com on December 7th, 2004


I have 3 half-hour video clips encoded as DVD-compliant MPEG files.

Using DVD Architect, I've created a project and placed all 3 files
into the project.

The preparation goes without problems, and the resulting burned DVD
plays fine on the PC, but is extremely jerky on my standalone DVD
players.

I should mention that I did my "test burn" on a re-writable DVD.
Does that make a difference?

I noticed that the bitrates of the files were 9 Mb/s.
I've reduced them to 7 Mb/s and I'm processing now.

Anything else to look at for jerky playback?

Posted by FLY135 on December 7th, 2004



<Mitch@hotmail.com> wrote in message
news:6nacr09uqotdmi5u5kofjmg2s8l9na5uj0@4ax.com...
Field order inversion. Check your encoder settings for top or bottom field
first. Switch the setting then make a DVD and see if it makes any
difference.



Posted by DeepOne@ix.netcom.com on December 7th, 2004


"Mitch@hotmail.com" <> wrote:

It might if your standalone players have trouble reading the type (or
brand) of disc.

It depends on exactly what you mean by jerky. An incorrect field
order setting in the encoder would be a possibility. You wouldn't see
that problem during playback on a PC, but it would show up on a
standalone player.


Posted by Mitch@hotmail.com on December 8th, 2004



Thanks...I'll try this.

By the way...what is the easy way to get TMPGEnc to create
dvd-compliant video?

It seems like no matter what I do, it ends up being non-compliant, and
creates errors.

For this most recent adventure, I used MainConcept.

Posted by DeepOne@ix.netcom.com on December 8th, 2004


"Mitch@hotmail.com" <> wrote:

What errors? And from what program?

TMPGEnc's Project Wizard should allow you to produce a DVD compliant
video easily. However, I suppose it's possible that some authoring
software would consider MP2 audio to be non-compliant. While MP2
audio may be technically non-compliant on an NTSC DVD, I don't think
I've ever heard of a DVD player that wouldn't play it.


Posted by Mitch@hotmail.com on December 8th, 2004



Here's what I'm trying to do. We have several DVD's with kids' shows
on them, many of which are 20 minutes or so. I want to consolidate as
many of these short shows onto a DVD as I can so that the kids aren't
handling the originals, and so there is less disk swapping in the car
when we travel.

And I also thought it would be a good exercise to get all of this
video stuff figured out, since I want to start editing down our DV
camcorder footage.

So, I used TMPGEnc DVD Author and wrote the files to the hard drive.
(That's "demuxing," right?)
When I bring these files into TMPGEnc DVD Author, their descriptions
are:

MPEG-2, 720x480, 29.97 fps 4:3, NTSC, 9800 kbps
Dolby Digital AC3, 48000 Hz Stereo, 192 kbps

This is DVD compliant, right?

I burned the DVD, and as mentioned, the playback is jerky.

So I wanted to follow the advice above, and re-encode the files
changing the "field order."

However, when I try to bring these files into TMPGenc, in the video
source field I can browse to the file, but for the audio source
field, when I try to point to the file, I get an error "File type not
supported."

So my first question is, what program do I need to "operate" on these
files, if I want to squeeze several of them onto one DVD?

My second question would be, what do I tweak to reduce their size?
Just bitrate? And is there something that automates the process?
That is, if I drop several files in, and they total 6 GB, the program
will do whatever recompression necessary to make them fit? Or is this
a pipe dream? :-)

Thanks for reading!



Posted by Neil Nadelman on December 8th, 2004


On Wed, 08 Dec 2004 15:41:51 GMT, "Mitch@hotmail.com" <> wrote:

So, let me get this straight: you want to take video from
existing DVDs, shrink them, then make a new DVD with this more
compressed footage?


-----------------------------------------------------
Neil Nadelman arvy@navzr-genafyngbe.pbz (ROT13)
-----------------------------------------------------
I have no fears in life,
for I have already survived Theta-G!

Posted by Mitch@hotmail.com on December 8th, 2004




Exactly! :-)

Obviously I'm not going for stellar quality, since they are cartoon
shows for the kids.

But I'm hoping that by doing this I can learn about this technology,
and learn whcih variables to tweak, how to tweak them, and observe the
effects and tradeoffs.

Posted by DeepOne@ix.netcom.com on December 9th, 2004


"Mitch@hotmail.com" <> wrote:

What is the total (approximate) running time of all the shows in
question?

[snip]

I think so. The video bitrate is pretty high though.

Well, if you didn't do any re-encoding (TDA can't re-encode), then I
don't think you would have a field-order problem. I would suspect a
compatibility problem between the discs you're using and your
standalone players. Do the original discs play OK in your standalone
players? Can you be more descriptive about exactly what you mean by
"jerky"?

TMPGEnc doesn't support AC3 audio (there might be a plug-in you can
buy for that capability, but I'm not sure).

I've done something similar before. I used DVD2AVI to transfer the
video from the DVD VOB files to the hard disk using the huffyuv codec
(it takes quite a bit of disk space, but it doesn't degrade the video
quality), and I set DVD2AVI to covert the AC3 audio to WAV format.
After the video and audio were written to the hard disk, I loaded them
into TMPGEnc for re-encoding. I repeated the process for each video
until I had enough of them re-encoded to fill up a DVD. Then, I
loaded the re-encoded videos into an authoring program (DVDLab in my
case) to author the DVD.

I would reduce both the resolution and the bitrate. Half-D1
resolution (352x480) looks very good, and it doesn't require as high
of a bitrate as full resolution. You can fit roughly 4 hours of
half-D1 video on a DVD if you use 2-pass VBR encoding (allowing at
least 4000kbps maximum bitrate for scenes which require it). You can
use MP2 for the audio (224kbps should be good enough).

Well, there's DVD Shrink. If you author a DVD (to the hard disk) that
is too big to fit on a single DVD disc, then DVD Shrink can do a very
good (and quick) job of re-encoding the video to make it fit on a DVD.
I suppose you could try using it instead of going through the process
of re-encoding with TMPGEnc; however, I'm not sure whether DVDShrink
can lower the resolution of the video, and full resolution video might
not be acceptable if you go much beyond 2 hours or so.


Posted by Mitch@hotmail.com on December 9th, 2004



Thanks alot for that! I downloaded the trial, and I'm using it right
now. It still won't recognize AC-3 without an optional plug-in, but
they include it with the retail version.

So right now I'm trying it with some files that don't use AC-3 audio.

Posted by Mitch@hotmail.com on December 9th, 2004



First, thanks alot for taking the time.
The shows total 1:44.

It's weird. It's not jerky in the sense of stop-amd-go video.
It's kind of a strange "flicker" effect, where a person's position
will change by, I don't know, maybe a quarter inch on the screen (32"
TV) and then snap back to where it should be.

Don't know if that description makes any sense, but that's the only
way I can describe it. Flickery.


I'm digesting the other things you mentioned now.


Posted by Mitch@hotmail.com on December 10th, 2004


Chris,

I used TMPGEnc XPress to create a DVD with three shows on it.
The second show plays back in Spanish! And I can't switch to any
other audio track.

I've gone back and verified that the source file plays in Media Player
in English. But when I import the file into XPres and play it back,
the audio track is Spanish.

I can't find any settings in the software for choosing a language or
audio track.

Weird!

Have you ever seen this?

Posted by Mitch@hotmail.com on December 10th, 2004


I used TMPGEnc DVD Author to look at the VOB files and write the
MPEG's out to the hard drive.

Followed this guide:
http://www.videohelp.com/forum/viewt...uthorereauthor


Posted by Mitch@hotmail.com on December 10th, 2004



This is freaking me out. I went and did it again. I used TDVDA to
write the MPEG file, making sure to choose the English soundtrack.

I verified that it plays in English (in Windows Media Player).

I add the file to the project in T XPress. I double click on in to
bring up the preview/edit window....and it plays in Spanish.

No comprendo!

Posted by DeepOne@ix.netcom.com on December 11th, 2004


"Mitch@hotmail.com" <> wrote:

The only thing I can think of here is that you have more than one
video file on your HD and you're getting them mixed up (perhaps your
programs are defaulting to different directories).

Earthlink's news server took a nap yesterday, and I missed several
posts in this thread. I was able to find them from another source,
and I'm responding here since I don't have the post available for a
direct response to it...

I suppose that does sound more like a field-order problem than
anything else I can think of, but I don't know how you could be
getting incorrect field order without having re-encoded unless it was
incorrect on the original DVD.

This might be useful:
http://www.digitalfaq.com/capture/atimpeg/restream.htm


Posted by Mitch@hotmail.com on December 11th, 2004



I thought about that, so I named it Frosty English, and I even tried
ripping one and deliberately chose the Spanish track, and named it
Frosty Spanish.

Both played back exactly the same: in Spanish.

I finally used DVD Shrink to rip the file, and deselected the Spanish
audio track so there would be no way to get it mixed up. That one
works fine.

I know it seems like a stupid exercise, when I could just copy each
DVD for the measly $.50 cost of a DVD-R, store the originals away in
the cabinet, and be done.

But I figure the best way to learn is by doing.

Since my goal isn't to copy movies, I'm not going to pursue this issue
any more. But I've learned alot about encoding, bitrates, audio
formats, etc., that will help in making my own DVD's.

My problem is, I HATE not knowing why something didn't work. And I
obsess until I figure it out...even if it's not important.

Posted by DeepOne@ix.netcom.com on December 11th, 2004


"Mitch@hotmail.com" <> wrote:

Was it the same video in each case? One thing I've noticed on DVDs
which have multiple audio tracks is that the audio track numbers are
not always consistent. For example, track 1 might be the regular
audio on most of the videos, but on 1 or 2 of them it might be some
sort of commentary while the regular audio is on track 2. So you
can't necessarily assume that the English and Spanish tracks will
always be in the same place; they might be reversed on some of the
videos.

[snip]

Well, if you figure it out, I'd like to know the answer too.


Posted by Bariloche on December 11th, 2004


On Thu, 09 Dec 2004 12:17:09 GMT, DeepOne@ix.netcom.com wrote:

DVDShrink does not re-encode, nor change the resolution. It just
throws away the less significative data.


Posted by M.L. on December 25th, 2004



I've never used DVD Shrink and am confused as to how it differs from
other DVD decryption software such as SmartRipper, DVD Decryptor,
CladDVD, etc., since they all throw away unused DVD data.


Posted by WEBPA on December 26th, 2004


The best way for you to obtain an answer to your question is for you to try it.
Personally, I've rarely seen artifacts viewing DVDShrink output reduced 50
percent or less on a (VERY good) 50" TV.


webpa



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