DGPulldown and Audio Sync problems using PowerDVD

[rocko1911]

Hello everybody,

I'm just playing around with PAL -> NTSC conversions and I use DGPulldown by Donald Graft to get the frame rate to 29.97 fps. I think DGPulldown is a great tool, but yesterday I got some problem with the audio: After using dgpulldown and authoring the movie with dvd-lab the audio is not sync any more. The longer the movie plays, the worse it gets. I absolutely do not understand how that can be.

So, this is what I do:

DGIndex -> TMPG to convert to 720x480, 25 fps -> DGPulldown (25->29.97, set timecode and set dropframes is checked)

When I try authoring the AC3 and the output by tmpg the audio is perfectly in sync. The m2v ES after doing the Pulldown has EXACTLY the same length as the one which has not been run through DGPulldown (the tmpg output) and of course I'm always using the same AC3 file.

This is absolutely strange to me. I have done some movies where everything was OK and I did nothing else. Has somebody got an explanation for that?

Thanks in advance,
Rocko

HOW DOES THIS THREAD DIFFER FROM THE ONE kevinm HAS OPENED? I HAVE THE SYNC PROBLEM IN POWERDVD.

[kevinm]

rocko1911,

this may be the same problem, but I dont know enough about the process to really comment one way or another. I owe Donald the information from DGMPEGDec for length for pulldown.mp2, I hope to have this information by this evening. Hopefully this will be helpful for tracking down the problem which I am seeing, and maybe it will relate to yours.

It would be good if is was the same problem, and the same fix.

Kevin

[rocko1911]

Hi Kevinm,

yeah, sure, probably we have the same problem. I'm also reading your thread with great interest and I'm sure Donald will have some great ideas.

I found out some thing yesterday evening bout my problem. The two m2v files have EXACTLY the same length, but after they are authored (both with DVD-Lab) the vob-video does not have this property any more. The pull-down version is about 1 second shorter (and that's approx. the desync at the end of the clip). So there's a problem with the combination of DGPulldown and the authoring.
When I use TMPGAuthor, everything plays fine (at least on the PC). But TMPGAuthor also tells me that the length of one GOP (18 Frames is too long). I guess i will use 15 frames in the GOP and try to encode again. I will report what happens then....I'm really curious about this.

[rocko1911]

Well, I just altered the GOP length to 15 Pics and also shortened the GOp structure. Everything seems to work fine now, even with DVD-lab.

I'll test this video on standalone and report what happens.

Rocko

[kevinm]

rocko1911,

excellent news. Now I need to figure out if it is my problem too. Time to read up on GOP again I guess. Been a while since I delved into that depth. I guess I have been trusting the applications more than I should have.

Just to get me started .. you said that the GOP problem was caused during the authoring. Was it just a setting in the authoring tool that needed to be tweaked or was it a bug which you had to fix later by some MPEG stream fixing application?

I am using NeoDVD at the moment to author the DVD, I also have PowerDVD but I trust that even less than NeoDVD. NeoDVD does a compliance check of the .mpg and claims it is compliant and is not re-encoding it.

The .mpg I feed to NeoDVD comes from TMPGEnc which I use to multiplex the pulldown .d2v with the original mpg audio.

thanks,

Kevin

[rocko1911]

Hi Kevinm,

well, to change the GOP length, you have to encode the video again. Hit the settings button in TMPG and check the different cards. On one of them you can adjust the max. GOP length. I set mine to 15 and also changed the pattern of B and P frames (so that the pattern length is not longer than the max. Gop length) to a shorter one by adjusting the number of P or B frames (I reduced one of them from 5 to 4, I do not remember which one it was).
Then I did the pulldown again and reauthored the DVD. So there's nothing buggy, I just changed settings.
When I was using the GOP length of 18 DVD-Lab didn't complain about the GOP length being too long and produced the desync output. The TMPG authoring tool complained about the GOP length, but produced sync output. After reducing the GOP length to 15 also DVD-Lab produces a sync output.


Rocko

[kevinm]

rocko1911,
thanks for the clarification, this is most useful. I will have a look at tweaking my settings in TMPGEnc tonight,

regards,

Kevin

[kevinm]

rocko1911,

I ran up TMPGEnc and checked the GOP settings which I used when I originally encoded my video, here is the settings I used:

GOP Structure: IBBPBBPBBPBBP
Number of I pictures in GOP: 1
Number of P picture in GOP: 4
Number of B picture in GOP: 2
Output interval of sequence header: 1 GOP
MAX number of frames in a GOP: 15
Output bitstream for edit (Glosed GOP): checked
Detect Scene change: checked
Force picture type setting: un-checked

these are the settings which I got when I loaded the standard TMPGEnc PAL DVD template.


If I read the above correctly I think I already meet the criteria you said I needed (pattern lengh not exceeing max GOP length and <= 15)

Perhaps I misunderstand what you were telling me, can you please confirm and if possible tell me the exact settings which you used.

thanks,

Kevin

[rocko1911]

Kevinm,

these are the settings I use, they're correct. You already got the right GOP length, as you are loading the PAL template. I load the NTSC template and change the framerate....
Well, maybe you should try antoher authoring tool now. How about tmpgauthor? I'm not sure, but I think there's a shareware version around?

Rocko

[kevinm]

rocko1911,
I dont know if you have seen my post to the thread which I started regarding DGPulldown audio sync issues but I have managed to get it to work, at last :)

The solution (as you suggested) was to use a different authoring program. I used DVDAuthorGui which is an easy to use application and is freeware. I don't know if it is going to be sufficient for the menu building steps I ultimately want to do, if not I will try out TMPGAuthor.

Interestingly the DVDAuthorGui reported that it was doing some fixing steps, I don't know what they are, I will study the log a little more and try to find out. Anyway, for DGPulldown it does appear that the choice of authoring program is critical,

thanks for all your help,

Kevin

[rocko1911]

Ooh, that fixing steps interest me, too!!

I'll try the program even so and report what happens to my video!!!

Thanks,

Rocko

[rocko1911]

Hi kevinm,

I tried DVDauthorgui with my video and there were no fixing steps. It just told me that it is ignoring nonstandard options (don't know what should be nonstandard, but hey it works :) )

Anyway, this is a good proggie. You can also author subtitles to your movie...

Rocko

[Paulcat]

Odd Gop, sounds like a James Bond villain...

I had the same issue with TMPGEnc, going from PAL to NTSC, I had it set at 18 which should have been fine (for NTSC), but MuxMan gave me a "complaint" at the end of authoring telling me the gop was too long in one instance. The final dvd still played fine on my standalone, so I didn't bother to re-encode the video.

I use a gop of 15 now for all conversion, it seems to work 100%

Paul

[kevinm]

Not sure what those fixing steps are but the DVD plays fine now in my Sony standalone player. As regards GOP, I use the PAL template in TMPGEnc, changed to 720x480, set to interlaced.


The fast panning shots are handled much better using this pulldown technique than anything I have achieved using avisynth. That is not to say I couldn't get as good a result from using some combination of avisynth filters but I have tried for months and haven't managed to get close to what DGPulldown achieves. Excellent stuff Neuron2!


As regards authoring programs which I have tried in this pulldown flow:

TMPG DVD Author works
DVDAuthorGui works

NeoDVD does NOT work


Kevin

[Guest]

I don't think you should encode interlaced. Why are you doing that?

[kevinm]

good catch!

I am sorry to confuse everyone, that was a typo

I am actually setting 'non-interlaced' for the encoding in TMPGEnc. I read that your DGPulldown needs the .m2v to be progressive.

As a side note, once I forgot to set 'non-interlaced' mode in TMPGEnc but DGPulldown still worked. Maybe if the captured AVI going into TMPGEnc is non-interlaced TMPGEnc will leave is alone. I am not doing the deinterlacing of the analogue PAL source in TMPGEnc, I am doing it during the capture process.

Kevin

[rocko1911]

What a luck that you're talking about it! i just noticed that I produced interlaced material with TMPG. Argh!
But at least I can assert that DGPulldown also works for interlaced material :))

Rocko

[Guest]

I need to clarify one point here so that no misunderstanding occurs.

DGPulldown will not work if the content is interlaced, i.e, the fields of each frame come from different temporal moments. The content must be progressive.