Audio/Video Sync Problems

[GordonT]

I have been experiencing audio/video sync problems with MPEG 2 files
recorded with a Digital TV Card and then edited with VideoStudio 8, the
DVD file structure being written to the hard disk and not a DVD (after
many a wasted DVD).

I apologise for the length of this text but I have spent many
days/weeks/months fighting this problem.

Having followed some of the other posts in this forum, I have tried clean
installs, many/all variations and orders of patch installs and DVD folder
regression and none of them have made any difference.

The problem I am having with editing MPEG 2 files is the final DVD output
plays fine to begin with and then at certain points there is (but not
always) a visually noticeable drop of a couple of frames although the
audio continues unaffected. This causes a sync problem with video/audio
from that point on, steadily accumulating with each occurrence. I
assumed that this was because of a few frame errors in the original MPEG
due to minor variations in the signal quality to the Digital TV card or
errors in the MPEG encoder while capturing the signal. On closer frame by
frame inspection of the MPEG from within VideoStudio, at the positions
affected in the final output, I can indeed see an odd pixel or two that have
no colour and are therefore incomplete. I cannot see these errors in the
source file using other software such as Nero Vision Express or whilst
playing with WinDVD. However........

I created a 2 minute project around the problem area and rendered it.
The resultant DVD structure played perfectly in sync. After many
attempts to recreate the problem, I found that the DVD would play
perfectly as long as the final output file was no longer than 33 minutes
and 15 seconds long. It didn't matter whether the error point was near
the beginning or the end or how many error points I included in the
project. Go over the 33:15 limit and all the error points became an issue,
no matter where they were in the project. I then tried this with other
MPEG files I have been having trouble with and found the same applies
but the length of time differs slightly from file to file, ranging from 28
minutes to 34 minutes, but is a consistant time for each individual file.

Having played a lot more to see if I could find a way around this problem
I found the following (although they did not help me find a solution they
looked suspicious):

1. Rendering the projects at their maximum 'good' length (around 30
mins depending on the file) using the MPEG codec and 8000 kb/s VBR
resulted in the final output being almost dead on 2Gb (looking at the
temporary mpg file which is annoyingly left behind by VS in the 'Convert'
folder). I used 8000 kb/s because this appears to be the default used by
VS for a new project when creating the final output files although I did
change the audio codec to MPEG and the bit rate to VBR to match the
original MPEG file. Could there in any way be something within VS that is
causing the problems when the file goes beyond 2Gb? I tried lowering
the bit rate so that I could create longer projects inside 2Gb and it made
no difference, the maximum time of a project before errors began was
still the same which would suggest that this is a red herring.

2. Using an MPEG cutter, I cut a copy of the original MPEG into the same
33:15 minute project I was using for my tests. This MPEG was approx.
700Mb. This is almost exactly the same amount of free physical memory I
have just before beginning the rendering process. Is this a coincidence?
Probably.

3. I have one MPEG that has an abnormally large number of frame
defects in a row (approx 100 frames with odd pixels missing). No matter
what I do I cannot stop the rendering process from dropping the frames
and causing a sync error. This is understandable and I cannot expect
miracles. However, it doesn't explain why WinDVD will play the source
MPEG file without any sign of problems or why I cannot see the same
errors while editing in Nero Vision Express 3 (which quite happily renders
the final DVD output with no signs of errors). It is obvious that Nero
Vision Express takes the time to analyze an MPEG source file before
importing it into a project, even splitting it automatically into separate 4:3
and 16:9 formats as it does so (an MPEG TV recording may begin in one
format because of adverts and then change to another for a program). Is
this step, that doesn't appear to happen in VS, fixing the problem?


I tried to find ways around the audio/video sync problem. The only one I
have come up with that works but is very messy is:

1. Create several projects, each no longer than 28 mins, which in total
cover the portions of the MPEG file I want to use.

2. Create another project and instead of editing an MPEG, go straight to
the 'Create Disc' option and add all the smaller projects into it. Now edit
in any chapters required. On the project settings make sure the 'Continue
to Play Next Clip' option is selected.

3. Create the DVD output file.

This appears to solve the problem as each Title/Project is rendered
separately (judging by the temporary .mpg files in the 'convert' folder) so
each is smaller than the time limit that appears to cause the problem.
This isn't a perfect solution as there is a very small delay of about .25 sec
between each title (project) when playing back the final DVD.


So, final questions:

Can anyone else with a similar problem confirm that I'm not mad and the
length (time) of a project really is an issue with dropped/corrupted
frames and video/audio sync errors?

Is there a setting which will force VS to automatically remove the
temporary .mpg files it leaves behind in the 'Convert' folder?

Am I missing something obvious, can VS analyze an MPEG file when it is
imported like NVE?

Is there a freely available software product I can use to analyse and
correct frame problems within an MPEG 2 file before I begin editing.

Does anyone know what the compression speed/quality setting does? I've
played with it and can find no difference in the output between 0% and
100%


After all this, I still like the feel and ease of use of VS8 and think it has
loads of potential but I cannot get a reliable DVD out of it more than 25%
of the time. It feels as though the engine has started as a camcorder/avi
VCD editor and has been patched to deal with MPEGs/DVDs
unsuccessfully. Until the problems are fixed, and how will I know if Ulead
continue the same patch name policy, I will have to resort to using the
clunky, sometimes non-responding, and down right horrible Nero Vision
Express.

Any help would be much appreciated as I would still prefer to
use VS8.

[jchunter_2]

You wrote:"This MPEG was approx.
700Mb. This is almost exactly the same amount of free physical memory I
have just before beginning the rendering process. Is this a coincidence?

I can't get past this point. You should have gigabytes of free space available if you are doing video editing of any sort. Twenty GB would be a good starting point.

However, your video/audio sync problems are shared by most of us. Ulead seems to have lost the recipe and we are waiting for a fix. I think you should send Ulead Tech Support your findings because it might help them.
John

[jchunter_2]

Re your alternative methods:
(1) Short projects (10 - 15 minutes) are easiest to manage and edit. Create an mpeg2 video file for each and ADD them to your DVD in the SHARE module. Burn your DVD with NOTHING in the timeline.
(2) Don't even think about adding Projects in the SHARE module because it will trigger well known bugs in Video Studio.

BTW, I have never seen a difference in the quality setting. I just max it out and leave it there.

[kevinreddog]

The only problem with this work around is that there is usually a half second delay between the mpeg's you created (and rejoined during the DVD burn process).

[GordonT]

I Wrote : "This MPEG was approx.
700Mb. This is almost exactly the same amount of free physical memory I
have just before beginning the rendering process. Is this a coincidence?

You Wrote: "I can't get past this point. You should have gigabytes of free space available if you are doing video editing of any sort. Twenty GB would be a good starting point."

You are talking about something completely different. I have 1 Gb of RAM (physical memory) installed of which 700Mb of it is free when I enter the rendering process (and an additional 2Gb of virtual memory). I have over 100Gb of disc space FREE.

As pointed out in both my post and by kevinreddog, using multiple projects or mpg files in the Share Module causes an unacceptable delay between them during playback.

I disagree with the suggestion it is easier to manage shorter projects.
I am trying to edit a TV recording to remove the adverts, which is easier?

1. Edit the original mpg file once and then render.
(Total: 1 operation)

2. Create 6 individual projects (maybe more depending on length of mpg)
to break the file down into 15 minute mpg2 video files (or alternatively
use an MPEG cutter).
Create a project with nothing in the TIMELINE and the mpgs in the
'Share Module' just to join them all back together again. And still with
a half second delay between them during playback !!!
(Total: 7 operations).

Lastly, I have made several DVDs by adding 'projects' in the Share Module (up to six 30 min projects, therefore 3 hour DVDs). The success rate has been 100% with no hint of problems or crashes. This means I don't have to waste time cuting or rendering six individual mpg2 movie files before creating the final DVD. It has worked successfully for the last six months using the original VS 8.0 install and continues to work for me in the last few weeks with the latest patches.

[kebrinton]

If I had this problem, I would start over.

Recently I deleted a MS Word document which I've worked on for more than ten years: a table of constantly changing information. It's always given me grief. Now, when I try to print it, it throws my printer into a schizophrenic state which persists for hours.

I finally deleted this file, and (more adept at Word than I was 10 years ago) rewrote it exactly as it was. Result: a totally compliant file.

I believe some files can have "hidden code" which makes them act weirdly. I don't know how it got there, but the behavior speaks for itself. I would think the same if a UVS project gave me similar problems.

[THoff]

finally deleted this file, and (more adept at Word than I was 10 years ago) rewrote it exactly as it was. Result: a totally compliant file.

It's a bit late now, but you could have tried Select All -> Copy -> Paste into a new document, if need be by going through another program such as WordPad as a filter. WordPad understands Rich Text, so most if not all of your Word formatting would have been retained.

[DVDDoug]

What worked for me was to create seperate MPEG files for for each complete clip. Then, re-combine the clips into a new project, joining them with transitions. Then, save this as one big MPEG file, which was used to make the DVD. (In both cases, I was editing with Video Studio and Authoring with DVD Workshop.)

Can anyone else with a similar problem confirm that I'm not mad and the
length (time) of a project really is an issue with dropped/corrupted
frames and video/audio sync errors?

I also came to the conclusion that this is related to corruption, but I didn't find any relation to length. I made an unedited DVD (over 2 hours) which was fine. But, when I made one with the "offensive scenes" edited-out (about 1.5 hours), I got the sync problems. I concluded that the editing process was screwing-up the MPEG integrity.

The other thing that worked for me (on the project I worked-on this past weekend) was to download the trial version of Womble Video Wizard, and use that as my editor!

Is there a freely available software product I can use to analyse and
correct frame problems within an MPEG 2 file before I begin editing.

My experience seems to indicate that the files need to be cleaned-up after editing, but before being "authored", or converted to the DVD format. (?)

The Womble editor has a function to clean-up MPEGs. I haven't tried that function... and it's $120 (after 30 days). I think their other program ($70) has the same tool.

I haven't tried these programs, but they're supposed to be able to fix-up MPEGs too:
PVAStrumento. (FREE!)
VideoReDo ($50)

P.S. In my case kebrinton's "starting over" technique did not work... it was one of many experiments that did not work!

[GordonT]

Starting over isn't an option. This problem occurs with the majority of my MPEG 2 files recorded using a Hauppage Digital TV card. I can only record a program once. If you mean start a new project, I've tried this many times and it doesn't make any difference, the fault must be somewhere in the rendering engine.

I hadn't thought of joining smaller clips together using the transitions, it sounds as if it might work. However, I shouldn't have to go through the additional stages of breaking down a large MPEG file to get around the
problem.
Cleaners are all very well but I spent hard earned cash on VS and shouldn't have to spend anymore to get around it's faults, especially as the Nero Express 3 editor/renderer (which I hate using) will create perfect DVDs using the same files without going through any additional steps.

[Trevor Andrew]

Hi Gordon

There may be something in your thinking re video length.

I have done a few test regarding audio sync’ problems.
I am using Vs 8 patched, but have not used the ‘burner engine patch’ as yet.

I have several mpeg 2 files of various lengths totalling 100 mins.
These were captured using Pal Dvd template at 4000 kbps.

The audio sync’ is perfect from capture , edit , create video file, but when I try to create a Dvd Folder the resulting Vob files are way out of sync’.

I have tried everything I can think of to change the way I produce the Dvd, from editing changes to menu/chapters.

Finally I produced a completed folder with no sync problems.

I reduced the file sizes to below 1 Gb. for all mpeg’s used in the burner engine.
Obviously this is not acceptable, but it does make good dvd’s.

Interestingly the burner module creates Vob files with a limit of 1 Gb

Each time I make a Ts folder using only 1Gb I get good results, use one larger than 1 Gb and the sync’ problems appear from that point.

I will do a few more tests then I am going to try the ‘burner engine patch’

Trevor

[GordonT]

That's very intersting. 1Gb at 4000 kb/s is going to be around 30 minutes of video, the same as 2Gb at 8000 kb/s. This is the time limit I found where the problem begins.

I have already sent my suspicions about the time length to the Technical Support team and will update this post when I get a reply.

1 Gb VOB files is an industry standard used for all DVDs, you will find that commercial DVDs are exactly the same. If the DVD Title is larger than 1Gb then it is split up into as many 1Gb VOBs as necessary.

Your comment has just triggered a thought. Nero Vision Express creates all its 1Gb VOB files at exactly the same length (1,073,739,776 bytes). All the shop-bought commercial DVDs I own also have 1Gb VOB files of exactly the same length although it differs slightly from disc to disc. Videostudio 8 produces 1Gb VOBs of differing lengths.

In light if this, does anyone understand how the IFO and VOB files are used during playback and could the small differences in length be causing audio/video sync problems?

[THoff]

FWIW, unless you are using CBR encoding, it his highly unlikely that you'll always wind up with exactly the same file size for each VOB...

[maddrummer3301]

Hi,
Just an added note in reference to editing/rendering mpeg2 files.
It has been reported by many previous users that enabling the use of
"smart render" when producing an mpeg2 file can cause
problems that you've been describing.

When creating the mpg2 file in the final stage try deselecting
"smart rendering" so the complete batch of edited videos gets
completely re-encoded.

Note: If one is rendering the video in the "Disc Creation" screen the
option to disable "smart rendering" isn't there.

Hope this helps,

MD

[Trevor Andrew]

Hi
Vob sizes

The VOB files I have been creating are :-
1024.137.216
1024.258.048
1024.215.040
216.674.304
Each main Vob does vary slightly above 1 Gb but I don’t think this an issue.

I use CBR.

Ok back to the drawing board.

From all the postings it does look as though the length of the video may play a part in the sync’problem.
I have successfully made TS files with large clips, then using the same material and settings created a bad one.
Very frustrating as everything appeared to be the same.

Will give the smart render option a try.

Thanks for the input, keep the ideas flowing

Trevor

Hi
Update

I have now made two TS folders containing 50 min 1.5 Gb file.

One was done using smart render and had the audio sync problem.

The second used the same project files but I did not use smart render during the Create Video File.
Then I made the TS folder.
Success, this file plays without the audio sync’ problem.

Taking longer to render is worth the wait when the completed file is ok

I have made many test TS folders using the same files, some have been ok whilst others suffered.
Why are some ok using smart render and others not?

Smart render is ticked by default, so when do we decide not to use it? At the moment when its to late.

Thanks MD for the smart render approach, a few more tests to do now

Trevor

[GordonT]

Got this reply back from tech support after sending them details from my original post. Appears that the Version 8.1 patch might be causing a problem. Looks like I am going to have to reinstall and start testing again. Still convinced the problem happened with version 8.0 as well. Will also give the smart render options a try.

From tech support:

Yes, the patch causes the AV sync...

Could you please try the following steps. I hope this helps.

1) Clean up temp files from\Start menu\Programs\Accessories\System Tools\Disk Cleanup.
2) Uninstall VideoStudio 8 from control panel Add/Remove programs
3) Reinstall VideoStudio 8 again

Do NOT install the update patch (uvs8_patch1_e.exe).

Then try to render, please tell us the result.