so close to fixing audio de sync!! argh!

[CMD27]

hey guys i just want to say this is a great site/forum.
so like a lot of people i have gotten to burning dvds. and also like a lot of people my audio gets de sync'd. About 30-45 mins into the movie the audio starts coming BEFORE the video. i have de-multiplexed the audio/video using TMPGenc, and i have goldwave, but i dont understand what to do next!
i read the article on resampling using sound forge but when i run sound forge it says RUNDLL module not found, what is that all about? if this helps this is my basic rundown: 1 encode to a .vob file using Xilisoft(takes about 1 1/2 hrs.) 2 use TMPGenc DVD author to create menu/chapters and make DVD folder, then Burn using the write tool that comes with it. What should i do???
oh and also i would like to know what everyone else's basic steps are to creating dvd's. and what you guys use for audio problems. thanks a lot!
PS-hope im not asking for too much!

[Forum Troll]

What kind of file are you starting with? MPEG? AVI?

[Tommyknocker]

Use Gold Wave as before to get your audio. Once you have it, select Effect=>Time Warp, and either FFT or Similarity (to keep the pitch unchanged), select and change the length of the audio file to match the video. Save as wave. Voilá!

[CMD27]

okay cool! but then what do i do with the wave file? do i remultiplex it with tmpgenc? can i just reencode the avi again using the new wav file or do i change it to mp3/AC3 using a different program? thanks a lot!

[Tommyknocker]

Yes, use the main TMPGEnc Plus! screen to load your video and wave files, then select the proper template for your MPEG file.

[CMD27]

okay so i changed the file length using goldwaves timewarp like you said, and now i am going to reencode using the original .avi file for video, and the new wav file for audio into system (audio+video). i hope this is right! i will tell you how it goes, thanks for all the help tommyknocker

[reboot]

If it's still out of sync because you've chopped off a bit, or simply added a bit, I have another method using Goldwave that works every time.
Post back if you need it

[CMD27]

reboot i am totally open to other ways of fixing this problem!
this is what iam reencoding to with tmpgenc as i type :MPEG-2 720x480 29.97fps CBR 5864kbps, Layer-2 48000Hz 192kbps,, but it is taking about 10 hours to do this, is this normal? should i just directly encode to es(audio+video) using tmpgenc will that speed things up? anyway please share what you have in mind reboot! thanks!

[reboot]

Tmpgenc 2-pass is going to take about that long.
Here's my version of correcting audio sync problems. Kinda long, but works for avi and mpeg easily.

1. The basic principle involved here is to strip out the Audio file (de-mux) then stretch or compress the audio frequency, 44.1kHz, and re-sample to 44.1 (for (S)VCD, 48khz for DVD). Then convert to *.MP2 format and re-multiplex with video stream.

2. Demux the MPG file so we can manipulate the Audio file. Run TMPGEnc, click on File and select MPEG Tools. Select Simple De-multiplex tab and for Input, browse to your problem MPG. Video and Audio output names will be automatically generated. The Audio being *.MP2 and video being *.M1V or *.M2V. Click Run and wait until its finished. Exit TMPGEnc.

3. We now have to estimate the approx time, in seconds, that the audio is out of sync and nearest to the end of the movie as possible. Simply play the original movie with WinDVD or similar player. Windows Media Player is not recommended as it can A/V sync problems of its own. Move slider to near the end of the movie and look for speech, gun fire, explosions, door slamming, etc where you have a precise Audio to Video match up. Estimate the time difference and not the length of the movie. Lets say we find the Audio trails the Video by about 1 second and the movie length was 48 min or 2880 sec (the door slams and about 1 sec later we hear the thud).

3. Run Goldwave and load in the *.MP2 file. Its also best to turn OFF the Undo feature to speed up the conversions (in Options / File...) Click on Effects and then Playback Rate. We need to change the 44100 Hz to sync the movie, use these formulae:

New Hz (Audio trails Video) = (Movie length in sec + Out of Sync in sec)/(Movie length in sec) * 44100

or

New Hz (Audio precedes Video) = (Movie length in sec - Out of Sync in sec)/(Movie length in sec) * 44100

So for our example, we have:

New Hz = (48x60 + 1) / (43x60) * 44100 = 44115

So change the Rate from 44100 to 44115 (or the number you calculated) and hit OK. Now click Effects again and select Resample. Change the 44115 (or what ever figure you have) back to 44100 and hit OK. Once the conversion is finished, hit Save. For Type select Wave (*.wav) and Attributes as 16bit, Stereo, Signed. Change File name if needed and hit Save. When it finish's answer No and exit the program.

4. We now need to convert our WAV file back to an MP2 form. TMPGEnc is the simplest to use for this. Run TMPGEnc, and click File, then New Project to clear out old settings. For Stream Type select Audio Only and for Audio Source, browse to our new WAV file and Open it. Rename the Output file name to something different than the original MP2 file. Now click Settings and change the Bitrate from 192 to 224, this is ESSENTIAL for a VCD. Do NOT change any other settings except Normalize in Setting button (do this only if the audio appears low in volume). Then click OK and finally click Start. When done, exit TMPGEnc.

5. Run tmpgenc and under mpeg Tools, select MPEG System Multiplexor. Browse for the original Video. Do the same for the new fixed Audio *.MP2 file. Now select MPEG-2 Program VBR. Enter an output file name (different from the original) and click Save. When done, play the new MPG file in WinDVD and check that A/V sync has been fixed. If its still out a bit, you need to start all over again from Point 3 changing the frequency Rate a bit higher or lower. Repeat until its fixed.

[CMD27]

wow, thanks! I will definately try that if this method doesnt work! in your method you just re multiplex the new audio& original video, is that the same as re encoding (which is what i am doing)?

[Tommyknocker]

No, it's completely different. Re-multiplexing does not re-encode, so there's no loss of quality.

[CMD27]

okay so after about 14 hours i have the mpg-2, but when i try to open it up in tmpgenc dvd author, it says no video sequence header! what did i forget to do when i reencoded?

[CMD27]

oh yeah and i just checked the new mpg in WinDVD and it was completley out of sync so i guess that did not work! well back to square one, i will try your method now reboot, and i guess i will remultiplex the audio and video together instead of reencoding. ill let you guys know how that goes!

[mpack]

About 30-45 mins into the movie the audio starts coming BEFORE the video.

Does it happen suddenly, with good sync up to that point, or is 35-40 mins just the point at which a gradual loss of A/V sync got annoying?

If it was sudden then it would be caused by dropped frames. I'm pretty sure that most of the cures described here assume that the problem is due to a timing error on the audio, and hence the will not actually fix your problem. If that is true then after changing the length of the audio you will find that the audio is now out of sync everywhere, except very close to the beginning and end of the movie. If this is what you get then come back here and say so, and I can maybe give advice on what to do about it.

[CMD27]

mpack to answer your question 30-45 minutes in the audio starts to gradually lose sync and just keeps getting worse. its not like all of a sudden 40 minutes into the movie it loses sync and the audio comes before the video by 1 -1 1/2 seconds. so its a gradual loss of sync starting at that point. oh and what do you guys think about Xilisoft encoder? i like it because it converts straight to .vob so fast. but whtas the point if its out of sync right?

[reboot]

If you're using dvdlab to author, don't bother remuxing.
Import the audio and video, then compile and check it in WinDVD.
If it's out of sync, follow my guide to adjust the audio, then import to dvdlab again, compile, and check again.
mpack has probably got the answer, if it's due to dropped frames, and not a timing issue.

[mpack]

mpack to answer your question 30-45 minutes in the audio starts to gradually lose sync and just keeps getting worse. its not like all of a sudden 40 minutes into the movie it loses sync and the audio comes before the video by 1 -1 1/2 seconds. so its a gradual loss of sync starting at that point.

Well, that has me flummoxed. AFAIK only two things can cause a loss of audio sync, one is a slight timing error - the symptom of which is a gradual loss of sync starting right at the start of the movie and increasing until the end, and which can be fixed pretty easily by following the helpful suggestions given by others here.

The other is dropped frames, which can cause the audio to suddenly lead or trail the video, depending on how the capture app handles it. The sync error in this case would be constant, up to the end of the movie or to the next burst of dropped frames, whichever comes first. ...

... Unless what you are seeing is the result of an increased frequency of dropped frames after 35mins or so. This could be caused by a fragmented drive.

There is a way to find out: load the source AVI into VirtualDUB and choose the "Edit|Next drop frame" navigation option. If you don't have any dropped frames it will say so. Check for a sudden burst of dropped frames around the 35 minute mark. Also check for the frequency of dropped frames after that.

[CMD27]

okay so i loaded the source avi into virtual dub and before it even opens it gives me this message: Virtual dub has detected an improperVBR audio encoding in the source file avi. This may introduce up to 74881 ms of skew from the video stream. If this is unnaceptable decompress the entire audio stream to an uncompressed WAV file, and recompress with a constant bitrate encoder. (bitrate: 150.5 kbps +/- 26 kbps.)
so i guess it was my source avi after all? and when i checked for dropped frame it says "no next dropped frame found"
so i demux the audio from the original avi source and recompress it at the rate it says? does this sound right, and what do i use to recompress it? goldwave?

[mpack]

Well, in that case I would open the AVI in Goldwave and save the soundtrack to an uncompressed (PCM) wav. Check afterwards that the duration of the wav exactly matches the duration of the movie. You can then load that wav into TMPGEnc and encode as MP2, or as AC3 if you have the AC3 Plugin.

[reboot]

If you have the room (your mpeg isn't too big) dvdlab will accept uncompressed PCM wav audio, so you don't have to convert.
If you do need to convert, use tmpgenc, as mpack has suggested.
Goldwave can't save as mp2 or AC3 (afaik).

[CMD27]

okay so now i have the uncompressed WAV file that is about 1.1 gb, and i checked it the WAV file is the same length as the original avi file. i am going to encode it with TMPGenc as mp2, just by itself right? then what do i do with with the mp2?

[Tommyknocker]

Once you encode the wave with the mp2, the result will be an mpeg file.

[Nelson37]

Excellent example of why there is a sticky on audio OOS. VBR audio encoding and dropped frames are both thoroughly covered there. Would have saved you a lot of time, also given you complete detail on how to solve.

Open in VDUB. Check for dropped frames. Save audio as WAV. Encode. Mux. Author. Burn.

[CMD27]

i looked around in the FAQ's/Guides/Tutorials for about 2 weeks before i started posting, and all it did was make me more confused! so i decided to ask to get more info.
i will look for the sticky you are talking about nelson.

[mpack]

I am going to encode it with TMPGenc as mp2, just by itself right? then what do i do with with the mp2?

Well, you already had a failed attempt at encoding the MPEG video right? Failed because the audio was out of sync? Well, demux the video from that attempt (discarding the audio). That gives you an elementary video stream, and the new mp2 is your an elementary audio stream.

What happens next depends on how TMPGEnc DVD Author works, which I can't tell you about because I'm not a TDA user. In the DVD authoring package that I use: I create a new DVD project, import the elementary video and audio streams into that project as assets, drop the video stream onto the video part of the movie timeline, drop the elementary audio stream (the mp2) onto the first audio track part of the timeline, save, make this movie the first play item, then tell the software to build me a DVD! The DVD is built as an image on your hard disk: if you have PowerDVD this is very handy for checking that all is well before final burn to DVD+/-R(W).

[CMD27]

okay that helps a lot! i have tmpgenc dvd author and i never thought of using the 2 separate files , i thought you had to use only one. well i have the elementary audio, and the elementary video so i will author it tommorow and tell you how it goes!

THANKS A LOT TO EVERYONE WHO HAS HELPED ME WITH THE OR IS STILL HELPING ME! YOU GUYS ROCK

[CMD27]

It worked video is in sync now! thanks to all who helped me.

[reboot]

That's what we're here for. Thanks for letting us know