Audio sync problems after capture to AVI using DVD-WS2

[tezohar]

Hi,

I use DVD-WS2 for the whole workflow of capturing from a MiniDV, adding chapters, subtitles and menus and writing a .iso file. I'm very satisfied with the results but I have 1 major problem: out of 11 MiniDV 1 hour cassettes I've processed so far 7 were excellent, 3 had audio sync shifts and 1 had major video/audio flow problems (short pauses and jitters towards the end of the cassette).

I've read previous threads about audio sync problems and the answer was always that the problem lies within the program that did the capturing. In this case it's DVD-WS2 itself. When I preview the movie during capture everything seems OK, however once the capture is over and a .avi file is created, the .avi file already has the audio/video problems mentioned above, even before I do anything else in the software, and even when viewed via a Media Player.

I tried the following:

1. Captured again in case it was a local problem in my computer. The results were exactly the same, so I deduce it's a consistent behaviour of DVD-WS2 and not a random peripheral problem.

2. I captured using Sony Vegas 6 and the capture was without any audio sync problems, but when I imported the .avi file into DVD-WS2 I wasn't able to use the auto-chapter-detection (by DV recording time-scan) and subtitle creation according to date/time.

Do you have a solution for me, either by tweaking DVD-WS2 in the capture phase, or by recommending how I should capture in another application but still be able to use DVD-WS2's auto-chapter (by DV recording time-scan) and date/time subtitles?

More info:
Camcorder: Sony DCR-HC90E
Movie format: MiniDV PAL 16:9 and 4:3 (Happened in both ratios)
Firewire Adapter: PCMCIA Texas Instruments OHCI compliant IEEE 1394 Bus host controllers
Software: Ulead DVD Workshop 2.0
Capture params:
Device control: MS 1394 device control
Capture Plug-in: Ulead DirectShow Capture Plug-in
Project Properties:
Disc Format: DVD
TV system: PAL/SECAM
Disc Template: High Quality, Compression 100%
MPEG files
24 Bits, 720 x 576, 25 fps
(DVD-PAL), 4:3
Video data rate: Variable (Max. 8000 kbps)
LPCM Audio, 48 KHz, Stereo

Thanks in advance,
tez

[DVDDoug]

I have one thought...

Since you have Vegas, try rendering your MPEG file with Vegas (after any editing). I think Vegas can do that. Maybe it's more tolerant than Workshop.

With Vegas, use the same settings as your workshop Project Template. Then, un-check the audio & video check-boxes that say Convert To Disc Template. The MPEG "data" should stay intact when Workshop converts you MPG file to VOB files.

This isn't necessarily a capture problem. It's usually a corrupt-file problem. This is rare with DV files (common with MPEGs), but since 7 of your 10 tapes are OK, I suspect that is the case here. And, I suspect the original data on the tapes is bad. Often, a corrupt video file will play OK, but cause trouble when you try to edit or convert it... So, this type of problem can be very difficult to track down. In your case, you have evidence that 3 of the tapes are bad.

Technically, you are not "capturing" video, you are simply transfering digital DV data from your tape to an AVI/DV file. This is not nearly as tricky as real-time analog capture and/or real-time MPEG encoding.

[tezohar]

Thanks for your answer. I guess you are right that the data on the tapes is sometimes bad, but note that Vegas overcomes these corruptions and produces a good AVI file while DVD-WS2 produces a bad AVI. The problems occur in what you call the copying phase and not after editing, which is even weirder, because, as you say, the operation should be simple.

If I use Vegas I don't even have to render the data to MPEG. I simply use the .avi file that Vegas created and edit it in DVD-WS2 and it works OK, but it seems that Vegas's .avi file does not contain the date/timecode so DVD-WS2 cannot automatically detect chapters and there's no date information for subtitles. The workaround for this is very tedious: I keep the corrupt captured .avi from DVD-WS2 and use it in DVD-WS2 to produce chapters and subtitles. Then I capture again in Vegas and import the already created subtitles (easy), but I still have to manually create the chapters (is there a feature to export/import chapter break points?)

Maybe I should focus on finding out how to make Vegas write the data/timecode into the .avi files so that DVD-WS2 can do the job with the chapters and subtitles by date/time? Will DVD-WS2 be able to do it, or does it rely on some internal information and flags that it writes during its own capture algorithm? Anyway, is it even possible to keep the date/timecode in Vegas?

I guess it's not the right forum but I'll ask anyway: Does anybody have any tips on how to avoid such corruptions on my tapes in the first place? My Sony Camcorder is relatively new and I don't mess with the tapes. I record only once on each tape. Does it mean that the tape is of bad quality (TDK MiniDV 60 ME, Sony dvpremium ME DVM60) , or should I avoid some operations with the Camcorder to prevent it? (e.g. I suspect it might happen when I take the cassette out of the Camcorder and then put it back in to continue shooting).

Thanks again for any tip you have,
tez

[skier-hughes]

(e.g. I suspect it might happen when I take the cassette out of the Camcorder and then put it back in to continue shooting).

Thanks again for any tip you have,
tez

If you review these tapes, have you done this to them?
If so, does the timecode keep reverting back to zero after you re-inserted the tape?
If yes, you need to learn to use your cam more efficiently for this type of use.
Always record your scene, then leave the cam recording for at least 10 seconds, even if it's while you put the lens cap on.
Then when you remove tape and re-insert it, you have some video you cna record over, without losing vital info. Doing it this way ensures the timecode is unbroken.

All apps have trouble with timecode that continually restarts.

[Devil]

There are several points that require clarification here.

Are you transferring the DV files during "capture" as DV type 1 or type 2? With type 1, the audio is interleaved with the video, which is not the case with type 2. I recommend type 1 only.

Another point is that your max bitrate may be too high for comfort; certainly, many DVD players will baulk at your settings. I suggest you make a trial at 6000 kbit/s constant bitrate and Dolby Digital 2.0 at 192 kbit/s, which is as foolproof as you can get with excellent quality. Try reducing the quality setting, as well, to 90. Mini-DV is already compressed so comes with artefacts; there is little or no point in trying to be more royalist than the king and using settings that make no improvement over these artefacts, cos they won't go away. (This is a constant bone of contention between another member here and myself: I've done frame-by-frame analyses at pixel level at different bitrates on different subject types and found no visible difference above 6000 kbit/s: he says that he sees a difference in the final video. I speculate that this difference of opinion is possibly due to the big difference in NTSC and PAL DV colour spaces - I use PAL 4:2:0, he uses NTSC 4:1:1).

[tezohar]

Hi,

Thanks to Graham & Devil for your replies.

I've checked the timecode and it seems continuous, so I guess this is not the problem, but it seems like good practice for the future.

I used to capture using DV type 2, so now I tried DV type 1. The results were very weird:

1. When I tried only the few problematic minutes with pauses and jitters it seemed to have solved the problem.

2. When I then captured a whole 1 hour cassette, that had only audio sync issues before (a small delay in video), the result was disastrous. Even during the capture I could see relatively long freezes. At first I though it was only a problem with the preview, but then it turned out to be a real problem in the captured file. It is very weird since DV type 1 is supposed to be lighter than type 2, but it seems that the software just couldn't keep up the pace of capturing.

Regarding the tip about output bit rate. I assume this controls only the output and not the input (capture). Since the current settings seem to work fine with my DVD equipment and future equipment will probably only improve, I think I'll keep the current settings just to be on the safe side.

Do you have any explanation for the weird results above? Am I wrong in assuming the bit rate affects only the output? Is there anything else I could try before giving up?

Thanks again,
tez

[skier-hughes]

If you capture as dv.avi then the bitrate is set for that file type.
Your mpeg settings will be for output only.

Have you tried capturing these problem tapes with another app?

Try movie maker, as it is already installed on your pc, or I find windv very good, a link here
http://www.myvideoproblems.com/WebPages ... rammes.htm

[Devil]

OK, I see you have only one HDD. This can always be problematic. Try a good check plus defrag. A heavily fragmented disk can cause this kind of problem. This is why it is recommended, where possible, to have a dedicated video drive which can be reformatted before each project. You also have to make sure that you have 3 x the free space available before starting a project. E.g., for 1 h of DV, it is recommended you have 40 Gb free.

[tezohar]

Hi,

Thanks for persevering with me
I've invested hours in more trials and comparisons. I've created a DVD captured by Vegas 6, I've captured using WinDV (nice lightweight utility -thanks Graham), I've captured with DVD-WS2 type 1. I have a few conclusions and still lots of confusion. Sorry for the long post, but there are lots of details and I hope people will eventually benefit from my painful experience.

First some more technical info and definitions:

• 1. My HD info is a little misleading (sorry). I do use an external Hard-Disk (Western-Digital 5400 rpm) over USB2. The last problematic type-1 capture was made when the HD had ~25GB free space, so I tried again with ~60GB free space and a freshly defragmented HD.
  2. There are a few types of problems in the final DVD (most of them are also in the .avi):
  • 2.1. Audio sync problem: The original audio sync problem is a small consistent delay (approx. 1 sec) between audio and video (video is delayed).
    2.2. Audio balance problem: Audio is fluent but there are parts when it fades a little or the balance/volume is not smooth.
    2.3. One-time jitter problem: A momentary one-time jitter of audio and video.
    2.4. Disaster: Many jitters and freezes until it's impossible to watch.

I've created (using DVD-WS2) 3 DVDs for the same tape. They vary only in the capture method:

• 1. Captured by DVD-WS2 with DV type 2.
  2. Captured by DVD-WS2 with DV type 1.
  3. Captured by Vegas 6 into one big .avi file (no scene detection).

AFAIK all 3 DVDs turned out identical in the parts that had audio balance problems and One-time jitter problems, so I deduce these are all problems in the original DV tape.

• 1. Captured by DVD-WS2 with DV type 2:
  • 1.1. Has the original Audio sync problem.
    1.2. No Disaster in .avi and in final DVD.
  2. Captured by Vegas 6 ( I have no idea if it's DV type 1 or 2. It's not mentioned anywhere):
  • 2.1. No Audio sync problem.
    2.2. No Disaster in .avi and in final DVD.
  3. Captured by DVD-WS2 with DV type 1:
  • 3.1. No Audio sync problem.
    3.2. Sometimes has Disaster in the last ~5 minutes:
    • a) Last time I wrote, the disaster problem was already in the .avi. The capture was done then with ~25GB free space on the HD, and the HD wasn't freshly defragmented.
      b) According to Devil's advice I freed ~60GB of space on the HD and defragmented it. The defragmentation was very quick because after freeing the space there was no real fragmentation.
      c) I captured ~15 minutes 3 times, each time it seemed there were a few jitters and freezes during the capture, but when I played the .avi later the problems were very elusive. They either disappeared or appeared in random places. Very weird.
      d) I then captured the whole 1 hour. The .avi didn't have the disaster problem, so I did the whole process, created a .iso file and burned a DVD ( with bit rate of 8000 ).
      e) When I played the DVD using my Pioneer DVD player there was the disaster problem in the last 5 minutes.
      f) I suspected it might now be the output problem so I played the same DVD on my computer using Windows Media Player. No disaster problem!
      g) OK, so I decided it's time to use Devil's output advice. I used the same .avi, chapters, subtitles, and menus to create another .iso file using 6000 as bit rate. I burned a DVD and it didn't have the disaster problem anymore. I also didn't notice any difference in quality.
  4. I also captured using WinDV, DV type 1. I had only 30GB free on my HD, the capture went very smoothly, 0 dropped frames, the .avi file size was only a little bigger than the one of DVD-WS2, captured with ~60GB free HD space (12,708,645 KB vs. 12,708,082 KB). The .avi file had no Audio sync problem, however it had mini disasters towards the end of the tape, but these were elusive and not consistent when I played it again (in Windows Media Player). It looked too much like the results I got with DVD-WS2 so I didn't progress further to create a DVD.

Conclusions and questions:

• 1. It seems that if I go "by the book" of all of Devil's advices to the letter then it works. Hurray!! Still I remain with an uneasy gut feeling that capturing with DVD-WS2 is very sensitive and unstable, and capturing with type 1 is even more sensitive than with type 2.
  2. Is it just a coincidence that Vegas's captures always yielded best results with no effort at all? Was I simply lucky, or is Vegas's algorithm more efficient?
  3. Is it just a coincidence that both times I had the disaster problem it was in the last 5 minutes of the cassette? (I had it in the .avi of another cassette when I captured with DV type 2) Maybe these scenes simply happen to need a momentarily higher bit rate?
  4. Why did I have to reduce the output bit rate from 8000 to 6000 only with the type 1 capture? Is the 8000 simply borderline for my DVD player and it's sheer luck to have failed only in this 1 case?
  5. What's the difference between the .avi files that show the disaster problem and those that don't? WinDV claimed to have had no dropped frames, so shouldn't the .avi be perfect? Vegas had 3 dropped frames and still it was as perfect as could be...

Thanks for reading all the way to the end
Even more thanks and extra points if you have more answers or insights
tez

[tezohar]

Just another thought that pops into my head:
The 2 most problematic scenes that created disaster problems came from 2 different tapes, they were in the last 5 minutes and also they both had relatively loud background music. Does loud music require more resources somehow???

[Devil]

OK< I haven't read the whole screed but alarm bells rang as soos as I read, "I do use an external Hard-Disk (Western-Digital 5400 rpm) over USB2." That is probably the cause of your problems.

1. USB can be very slow for transfers, especially if you have other items on the same bus, such as mouse, keyboard, printer, scanner, digicam etc. These are interrogated sequentially, so you have time-sharing for each extra thing on the bus. his can slow down data-transfer enormously

2. Your disk speed is 5400 rpm. This is slow by modern standards.

3. Your disk is obviously not the newest and it is unlikely that it has sufficient buffer capacity to cover the gaps.

The symptoms you describe are typical of inadequate data transfer rates to/from HDDs.

IMHO, you should always use high-speed internal disks for video work, whether SCSI, IDE (master) ATA or SATA. External disks can be used for the storage of data transferred from your working disks.

I wouldn't mind betting that installing a good working disk will solve your problems.

[tezohar]

So you practically say that I have too many "on the edge" situations:
The elusive problems while playing some of the .avi files are because of inadequate data transfer rates to/from my HD.
The disaster problems in the final DVD is because the bit rate is too high (8000).

So now I'm not sure at all that my .avi files are really bad. Maybe I got confused because of local transfer rate problems while playing the .avi.

If WinDV states 0 dropped frames does it mean that the .avi is actually perfect and will stay perfect all the way to the DVD (no more places in the work-flow to really lose data. The worst that could happen is slower processing time), or are there other parameters that measure the quality of the .avi (compared to the actual DV data)?

Is there a way in DVD-WS2 to see how many dropped frames there were?

[skier-hughes]

I wouldn't mind betting that installing a good working disk will solve your problems.

I wouldn't bet against you on this one

USB2 has a higher burst speed than firewire, but it's ability to sustain high data transfer is poor, so creating the problems you have.