Can you correct Audio Sync problems in DVD Authoring tools?

[KetchSumAir]

What I'm doing:

1) demux video and AC3 6ch audio from a VOB file
2) Run AVISynth -> TMPG creating a new .m2v file.
3) DVD Author mode in IFOEdit to create VOB file from .m2v file created in step 2, and .ac3 created in step 1.
4) Using DVDAuthor (TMPG), or DVDLab, read in VOB file created in step 3, and create a valid DVD structure for burning.
5) Burn to DVD

Additional Info:
I don't want to tamper with the sound - only the video. The reason for this is I'm converting a 4:3 letterbox format video to a 16:9 format to watch on my HDTV (wide screen).

The original VOB file is in-sync. If I remux the demux'd video and audio streams created in step 1, the resulting file is in sync still. I do no cutting/pasting of any kind to either the video or audio files. My only guess is that the video header has some kind of audio delay number that's getting lost when I re-encode.

So, what I've done to get around this is use the DVD author feature of IFOEdit. It allows you to specify an audio delay - the resulting VOB file is in sync. But, IFOEdit does not give me a DVD file structure that is compatible with my DVD Player. So that's why I need an Authoring program, other than IFOEdit.

It would be very convenient to just adjust the delay while authoring, since I have to use an authoring program anyway. Does anybody know of a cheap (under $100) or free authoring program that allows you to change/delay the audio stream? I've heard DVDMaestro does this, but it appears that it's no longer for sale.

Thanks for the help.

[KetchSumAir]

So it looks like the answer to my question is that IFOEdit is the only DVD Author program capable of adding Audio delay.

There are many other ways of fixing initial audio sync problems, but having this option in a more complex Authoring program than IFOEdit would have been a nice bonus.

[ImaWeTodd]

You can use vobedit to see the delay. Open the vob, there is a menu option to show delay.

Try before and after vobs.

If you are using avisynth, can't you just add black or cut the video? Just at thought.

[Dick White]

KetchSumAir, I can't help but wonder why you are going to all this trouble (although I find reading about it very educational). You didn't mention wanting to edit in any way. Can't you just zoom the LBX format on your HDTV? Am I missing something?

[wwaag]

To quote KetchSumAir "But, IFOEdit does not give me a DVD file structure that is compatible with my DVD Player. So that's why I need an Authoring program, other than IFOEdit. "

Don't understand this. I've used IFOEdit many, many times and never had a problem with the 3 standalone players I have (2 Apex and a Pioneer). I've also used Tempgen DVDAuthor plus MovieFactory 2--again, never a problem. It may be that the problem lies with your standalone player--not IFOEdit. Suggest that you try your IFOEdit authored DVD on another player--after all, a new player can be a LOT cheaper than new authoring software which may NOT be the answer. Moreoever, I don't know of any software that enables you to adjust audio delay--certainly the ones I've mentioned don't, except IFOEdit.

Good luck.

wwaag

[KetchSumAir]

All,

thanks for responding. I think I have my answer, but I feel it's important to answer the questions you guys have brought up. I'm planning to create a guide on this site based on my work, assuming I can get all the details of what I'm doing figured out.

@ImaWeTodd

Sorry - I looked into VOBEdit last night, but didn't read your post close enough - I didn't look through the menus. This would be a really nice feature if it's accurate. I question it's accuracy without trying it 'cause DVD2AVI will put an audio delay # in the file name of the extracted audio. I'm hoping that DVD2AVI don't use the same # VOBEdit does 'cause DVD2AVI only has about a 80% success rate in terms of reporting the correct audio delay to be in-sync.

@Dick White
You wouldn't believe my surprise too, when I found out I had to do this! (A bit of anger accompanied that surprise 'cause I payed good money for a 'junk' DVD).

Here's the deal:

I have a HDTV - 55". That gives me 2 issues: 1) It can't correctly handle 4:3 movies (explained below), and 2) It has a way of showing almost any video defect, which causes me to be very picky about video quality.

The 4:3 letterbox zoomed in would work if I had an adjustable zoom factor for my HDTV as it cuts off part of the movie in zoom mode. My HDTV has many different viewing modes, but the only one that really works is when I put it in 4:3 mode (gray side bars on left/right sides). This will make the picture look good, but SMALL! (the picture is basically framed in now - bars on all 4 sides). Even if the HDTV had adjustable zoom, I probably wouldn't like it 'cause it's doing real-time what I'm able to do with re-encoding the movie (changing it from a 4:3 letterbox to true 16:9). This causes digital artifacts that I'd rather not have to live with. If I encode it to the new aspect ratio, most of these new artifacts are removed as AVISynth's resize commands work much better than my built-in TV's resize command(i.e. zoom).

@wwaag

I, too, thought IFOEdit was 100% compatible. And, with MOST movies, it works fine. However, there are a few movies that just won't work authoring from IFOEdit. It has something to do with what IFOEdit expects to see in the original files (I don't understand the details). Baldrick has already admitted this himself at the top of the IFOEdit guide he created.

[KetchSumAir]

Ooops forgot to answer ImaWeTodd's second question:

If you are using avisynth, can't you just add black or cut the video? Just at thought.

Yes of course you can. The big problem with this method is I don't know if the video is out of sync until AFTER I've ran it through AVISynth, and TMPG, and got a result. So, what I'm doing now is using MPEG2Cut if the video lags the audio(cuts some "unneccesary" video out at the beginning), and VOBMerge if the video is ahead of the audio (adds some black frames to the front). Even this is an excersize as I generally don't guess 100% correct the 1st time. However, the advantage with this method is it's much faster than IFOEdit 'cause you can use just a fraction of the file until you line things up. Then, do it once for real using the same method (after which, it's ready of any DVD authoring program), not needing IFOEdit's delay adjustment ability. With this method, it generally only takes me maybe 10 mins (after the video is encoded) to find the correct sync number.

[Dick White]

Interesting. I've had a Pioneer widescreen analog set for 4 1/2 years and I quit buying DVDs unless they are anamorphic widescreen because I don't like the loss of quality when you have to zoom. I have a zoom mode that works pretty well for every aspect ratio, but the extra resolution of the anamorphic transfers makes an incredible difference (plus you also know that it is a new transfer and not one done for VHS years ago).

I would have thought that re-encoding would have added more artifacts, and of course there will be a loss of quality because you can't add resolution that wasn't there to begin with. So, I'd be interested in knowing how things turn out when you get this solved. Do you, in fact, beat the TV in quality? And, of course, was it worth the trouble?

[KetchSumAir]

@Dick White:

I have already mastered (well, with most movies) the conversion. The reason for this question was to do with optimization of my "flow". However, the latest movie I'm working on (Mission Impossible) is the worst I've seen. It's looks to be a literal VHS-to-DVD copy. No, it's not warez - I paid good $$ for this DVD at a store. However, it's not only recorded in 4:3 letterbox mode, but at 29.97fps telecined as well. I'm beginning to hate Paramount pictures . Thier DVD's are by far the worst I've seen.....but I now digress.

So, basically I wrote all that to say the the quality, in my opinion, is close to what a low-quality production DVD would be. Much better than what my HDTV can do, but not as good as some of the higher-quality production DVDs.

I highly recommend doing this to people in a similar situation as me as the quality without doing this is so lousy that I really don't enjoy watching the movie any other way.

As far as your 2nd question: Is it worth the trouble?

Well, hopefully for you and others that follow after me the answer is yes (I intend to make a guide). But - I must be honest - I would NOT have attempted this if I would have know the depth of this pit I walked into. Now, having said that, I'm now able to do all that I need to do to get Mission Impossible correctly backed up to DVD, and watchable on a HDTV. Now that I know how to do this (almost completely), I'm glad I have that knowledge.

I must say that I'm surprised how many people participate in this website that don't have HDTV's and the like. I would have thought that the "videophiles" would be here and I would have been able to have much more help on this topic, but it seems that this website mainly attracks the computer crowd.

Since you're interested, when I get all the kinks worked out, I'll post a picture of the re-encoded movie. It will boggle your mind how good it looks compared to the HDTV zoom.

[Dick White]

I'd love to see it.

Seems like Paramount and Fox were the last of the major studios to do anamorphic transfers, but both do pretty good jobs now. At least MI-2 is enhanced.

[ImaWeTodd]

Hopefully some more info for ya:

Quote from Maestro Manual

Usually (but not always), MPEG video is “timestamped.” This is embedded timecode
information, typically captured at the same time as when the source video was originally
encoded. DVDMaestro and DVDConductor are able to recognize timestamping. In fact,
when you placed the original video asset into the Video Timeline, you may have noticed
that the Timecode Timescale (the one directly above the Video Timeline) switched to
correspond to the video asset’s timestamping.
Audio encoded in AC-3 format may or may not be timestamped. In the AC-3 Audio
Encoder tab of the Encoder Settings window (as detailed in the Spruce Technologies
Encoder Guide), this is determined by whether you used a linear timecode (LTC) feed
from the source transport and activated the Use LTC button (the one that resembles a
“watch”) at lower left of the tab. If this button is selected, and a valid LTC signal is
present, the encoder captures the timestamp information. If it is not, then the encoder
inserts values of “00:00:00:00” (“midnight”) for timecode throughout the asset.

Seems to me you AC3 has timestamps, and your new mpv does not, or does not match.

Maestro also uses a timeline. If the audio is not in sync, you can move it on the timeline and preview.

The new Adobe product 'Encore' I'm sure has a timeline. You can probably also adjust the audio sync on their timeline.

Another thought is to see if TMPGEnc can insert time stamps. I know CCE does. Given this it seems you should be able to match your new video to the ac3.

[KetchSumAir]

@ImaWeTodd

Thanks for the info - that helps alot, in terms of understanding the problem. However, I'm in no position to spend $550 for an authoring program, so Encore won't work 4me.

I wish I could get ahold of DVDMaestro, but that is no longer sold.

TMPG will shift audio, but to do this you have to re-encode the audio as well as the video. I guess there is no "easy, cheap" way of doing what I want. However, I do have a method to get all in sync, so all is not lost. I was just hoping a cheap authoring tool would have this feature (my method involves a combination of using Avisynth, Virtualdub, and VOBMerge - to be documented clearly in an upcoming guide I'll be posting).

Thanks for the help.