mpeg-2 - 2:3 pulldown problem

[TaGam]

I'm working on authoring a dvd of two videos I converted from AVI to MPEG-2...

Tools I'm using:
- TMPGEnc (to encode to MPEG-2)
- DVDlab Pro (to author the DVD)

I had no problems with the first one but the second one, for which I believed I was using the same settings, somehow came out as 2:3 Pulldown.. so when I play it back the voice goes out of sync..

Now heres my real problem... I don't have the original AVI anymore and have no possibility of getting it back.. and both TMPGEnc & Virtual Dub say the MPEG-2 is an unsupported format so I can't re-encode the video..

Any help would be much appreciated...

[johns0]

Demux the clip and use pulldown.exe to strip the 3:2 pulldown flag from it.

[TaGam]

..Thank you tha worked, I was able to remove the pulldown flags and encode the video back to AVI @ 23fps..

BUT now I'm trying to re-encode it again to MPEG-2 - 29fps (for DVD) using TMPGEnc and the only 'encode mode' it lists is "3:2 Pulldown when playback", then when I import the MPEG into DVDlab it says its 2:3 Pulldown AGAIN!

I have no idea what to do....

Once again any help would be much appreciated...

[SLK001]

I can't really follow what you are doing (but then, I'm not trying all that hard).

First, I don't know why you were re-encoding your .M2V after you demuxed the thing (and by the way, demuxing doesn't give you an AVI file, but it gives you an elementry MPG2 stream - thus, the .M2V extention).

Anyway, adding a pulldown does NOT change any timing of your video (except for DROP FRAME TIMING, which is a special case). AND, a 2:3 pulldown is required if you want to make a DVD out of a film based source.

Your sync issues probably arise from the lack of timing information in your original audio stream. Perhaps if you could give us some idea as to how and how much the two are out of sync.

[TaGam]

ok, here's excatly what I'm trying to do (I should point out that this is my first attempt to make a DVD)...

I have two video files that I want to put on a DVDR for play on my standalone DVD player:

The first is 1 hour 26 minuets - the original was in AVI format
The Steps I took:- Used Virtual Dub to fix an audio header problem & Insert subtitles
- Used TMPGEnc (wizard mode DVD - NTSC) the only things I changed were: Video mode - Full Screen {Keep Aspect Ratio} and lowered the bitrate (to keep the file size low, I believe it was 4200kbps)
- Imported the file into DVDlab and used the built in Demultiplex to split it.
DVDlab says the video type is NTSC

The Second (the one that is giving me problems) is 1 hour 36 minuets - the original was in AVI format
The Steps I took:
- Used TMPGEnc (wizard mode DVD-NTSC) the only things I changed were: Video mode - Full Screen {Keep Aspect Ratio}
- Imported the video into DVDlab and used the built in Demultiplex to split it.
DVDlab says the video type is 2:3 Pulldown

I then completed my Menu system and clicked to complete the DVD, at this point it gave me an error message something to the effect of "You are trying to mix ? and D1 Full Streams, You can ignore this message but some DVD players will not play this disc"
I ignored the message assuming that it was something to do with the bitrate being different and continued....
When the encode was complete I opend the files using PowerDVD.. The First video played without problems, the Second played fine in the beginng, I skipped ahead to somewhere around 1 hour in and the audio was about 6 seconds behind the video.

That was when I went back to DVDlab and noticed that the First video was "NTSC" and the Second video was "2:3 Pulldown" so I posted this message.

After reading the reply I demuxed the Second video and used pulldown.exe to to remove the 2:3 pulldown flags..

This left the video file in m2v format @ 23fps.. (which I still have)

I then (in a possible misguided attempt) converted the file to AVI using Virtual Dub, thinking that I could use TMPGEnc to once again convert to MPEG-2 (this time without the 2:3 pulldown problem)... but it ended up the same.. So I posted my second message...

Hope that clears up exactly what I'm trying to do...

[Nelson37]

OK, first the term "AVI" does not offer enough info about the original file. An "AVI" could be Divx, Xvid, (several versions of each), uncompressed, Huffy, etc.

Second, you do not specify if the films are related in any way, or from same source (creator). Sounds like they are not.

The error message about D1 and ? indicates that the second file is a different resolution than the first. This could be a problem, but usually not an audio synch issue. The pulldown issue is most likely NOT your problem.

Illegally created Internet-based video files are like buying food from a street vendor in a third-world country, you never know what you are getting. Can you play the file in the original format without synch issues?
Have you read the very extensive sticky about synch issues? Have you checked for bad frames? Did you know that the simple act of fast forwarding in your playback software may be the sole cause of your problem?

[TaGam]

1. Both AVI's were originaly in DivX 5
2. They from different sources and are unrelated
3. In their MPEG-2 format they are both 720x480.. the only differences listed in the DVDlab window were the NTSC Vs. Pulldown and the bit rate on the Second video is nearly double that of the first.
4. I could play the originals back with no problems.
5. I've read the sync sticky..
What's really throwing me is that the sound was fine in the original and its fine in my re-encoded 23fps m2v & AVI (Divx5) BUT in the demuxed version of the pulldown version the video was 6 seconds longer than the audio.
6. I am aware of the fast forwarding issue and I'm 99% sure thats not the problem.

[indolikaa]

Illegally created Internet-based video files are like buying food from a street vendor in a third-world country, you never know what you are getting.

Nice stereotype.

[Nelson37]

No stereotype, this is based on personal experience. My comparison was intended to indicate the highly variable nature of products produced without a certain degree of standardization. While a substandard product is by no means guaranteed, nor a quality one assured by the standards, the odds definitely do change. Also, aside from quality, the very definition of things change. A simple draft beer is vastly different in Germany (strong), England (warm), America (mostly crap). Smoked eel is not exactly common where I'm from.

Internet video varies dramatically in quality, content, source type, intended destination, production methods, etc. This is neither good nor bad, except for the overly sensitive. Just be prepared to improvise.

On the synch issue, is it constant or does it gradually change? Is it possible the original was PAL 25fps? Have you tried extracting the audio as a WAV file and re-encoding using that? Try running the math on the number of frames, various FPS, and the exact audio timesynch difference to see if there is any correlation.

[TaGam]

When in 2:3 Pulldown it gradually changes, after one hour the audio is about six seconds behind the video.

I've just done an experiment with some interesting results:
I extracted the audio from the 2:3 pulldown MPEG-2 and compared it to both the 2:3 Pulldown (@29fps) & the non-pulldown video (@23fps)

Original Video (with no problems) Length 1:36:28
Extracted Audio length 1:36:28
2:3 Pulldown Length: 1:36:22
23fps Length: 1:36:28

So I took the two that were the same, the 23fps vid and extracted audio and imported them into DVDlab, which told me '23fps is not acceptable and it must be converted to 29fps via. 2:3 pulldown', when it was done converting it the video became 1:36:22

with this I'm completely convinced that this is a 2:3 pulldown but I can't seem to get the video to 29fps any other way... any ideas?

[SLK001]

You have a "DROP FRAME TIMING" issue. You probably need a NON DROP FRAME TIMING video to sync with your audio.

Read up on this and try some experiments.

[TaGam]

ok, I've been reading and experimenting with drop frame timing (as best I can with my limited understanding) and I think I'm doing something wrong...

First try:
used pulldown.exe on the 29fps pulldown video with drop_frame true (resulting time 1:36:22)

Second try:
used pulldown.exe on the 29fps pulldown video with drop_frame false(resulting time 1:36:22)

Third try:
used pulldown.exe on the 23fps non-pulldown video with pulldown enabled & drop_frame true(resulting time 1:36:22)

Fourth try:
used pulldown.exe on the 23fps non-pulldown video with pulldown enabled & drop_frame false(resulting time 1:36:22)

Am I doing something wrong (I'm working under the impression that when it works the time should be 1:36:28) ?
Is there another program I should be using?

[Nelson37]

You could try a hard telecine, it's the "Apply 2:3 pulldown" switch in Tmpgenc, not the "on playback" on.

[TaGam]

You could try a hard telecine, it's the "Apply 2:3 pulldown" switch in Tmpgenc, not the "on playback" on.

...problems with that:

TMPGenc won't open the original MPEG2, the M2V or the MPV (says its not a supported format) the only one it will open is the re-encoded AVI(divx5) but "3:2 Pulldown when playback" is the only option.

[SLK001]

Don't worry about the times of the various elementry streams (they are often different). The authoring program should interleave the V&A properly (with the timing formats properly accounted for).

Use VOBEdit to open your VTS_01_1.VOB file, and look at the header of the first frame's header. There is an entry called DROP_FRAME (or something like that). If it is a "1" then you have drop frame timing - "0" and you have non drop.

Whichever it is, change it with PULLDOWN. Then recompile your DVD then check for sync.

[TaGam]

ok... Just finished doing that...

The original was Drop Frame 0 so I added the Drop Frame Flag...
No Change.. It still slips out of sync...

Any other ideas?

[TaGam]

...I think its time I gave up on this one...

Thanks for all your help everyone.. 8)

[proxyx99]

Simplest way is to stretch/shorten the audio track. Vegas can do it in a sec. Load Video and Audio tracks (timeline) and adj. Audio to match Video length (I believe you need to hold shift key while stretching). Check for sync. If I'm not mistaken you can do that in VirtualDub as well (not in the timeline but by adjusting the values). If audio speed varies (inconsistent A/V delay...), cut audio in 2, 3 parts and adjust indiv. Good sound editor will do the same (stretch without pitch change).

[dafreak]

when you converted the mpeg2 back to avi @23.97 fps, was the audio and video in sync?