Bad Audio on wedding DVD - attempts to correct ruin sync

[baldrick45]

Hi Guys

Typical noob question I'm afraid but I have at least tried a few things for myself.

Problem - Wedding DVD sent to my Mum has sound but it is very low - you need to turn sound on the telly up to max to hear anything clearly. It doesn't appear to be just poor miking / poor audio capture because the sound is quite clear when you "pump up de volume". It just severely lacks volume as recorded onto the disc.

I offered to try and fix it and began by extracting a .wav of the soundtrack using Xilisoft DVD audio extractor. I pulled that into Audacity and normalised it using default settings. Still a little quiet but a big improvement - good enough to do the job. Exported the normalised soundtrack as another .wav and tried to run the original Vobs through Tmpgenc DVD Author 1.6 but merging in the new .wav file as the audio track.

Tmpgenc threw a fit - "illegal audio format - use AC3, linear PCM or MP2". Now I thought the .wav output from Audacity should have been in LPCM format and worked OK but not to be beaten I tried to feed the .wav through Headac3he - headache also failed to recognise the file as a valid .wav.

Back to Audacity - export as MP3. OK that worked. Into Headac3he - source file opens OK but can't find AC3 as output and selecting AC3-Wav from the dropdown won't "stick". OK third attempt - Convert the MP3 to MP2 - Bingo - that generates an output and DVD Author accepts the sound file for muxing against the original VOBs.

20 mins later I'm re-burning the DVD. I pop it in the player and for the first min or two things seem perfect.... but as I skip chapters I find that the audio sync breaksdown the further I get into the DVD by about 30 mins in, I estimate I have a good 6-7 second disparity.

Now for a noob I think I've given the job a god rattle - I think I've been reasonably inventive and persevered beyond the obvious "Awh just feckin' forget it" moments. I hope that some of you experts may even have been amused by what I've tried.....

So please - someone - please tell me if I've done something wrong and what else I could/should try. I did go back to basics and use VirtualDubMod to extract separate .wav files from the three VOBs but then called it quits (for the day) before I wasted any more time and effort playing with these.

Any other software likely to work better? I have a few other packages available BeSweet etc which i could play with but am reluctant to go much further unless there is a good chance of a result. Alternatively - If I rip it to Divx and convert back are there any of the Divx2DVD packages which would normalise the soundtrack as they convert it back?.

I've encountered sync problems before in converting Divx TV episodes back to DVD and after trying a few found that VSO ConvertXtoDVD rarely lost sync but it has no options to tweak the sound in the way I would need to.

Ah well - enough chat - I'm off to bed. Will check back tomorrow

Baldrick45

[FulciLives]

First use DVD Decrypter to RIP the DVD to the computer. I would use FILE MODE (SELECT ALL FILES) ...

After that use DGIndex to create a D2V project file. Actually you want to pick the option that not only creates the D2V project file but will also demux the video.

After you do that you should have a D2V file ... a MPV file (which is just the video) ... and a 3rd file that is just the audio. The audio file will either end in .wav for PCM WAV audio ... .ac3 for AC-3 or Dolby Digital audio ... or .mpa for MP2 audio.

The reason you want to use DGIndex is that it will demux "correctly" and a delay value (which can be positive or negative) will be in the audio name.

For instance the audio name might be something like this ... "WEDDING T01 2_0ch 256Kbps DELAY 0ms.ac3"

In this example we have 2 channel AC-3 audio at 256Kbps bitrate with a 0ms delay value. Chances are you have a negative or positive delay value.

You need to know what that is so you can "account" for it.

There are various ways of doing that but it depends on the format of the audio.

So do what I said and report back with the delay value and what type of audio it is along with the bitrate etc.

- John "FulciLives" Coleman

[baldrick45]

FulciLives

Many Thanks for the response. I did as you asked and got the following audio file,

VTS_01_1 T01 2_0ch 192Kbps DELAY 0ms.ac3

Which following your example I now know to be a 192Kps AC3 file with a 0 millisecond delay

So where to now O wise one!

baldrick45

[baldrick45]

FulciLives

Still interested to hear your thoughts (expert advice is always good) but I just cracked it (This time anyways).

I took the extracted AC3 file and opened it in Goldwave. (lost a bit of faith in Audacity's Wav files) Normalised it to 90% and saved it as a straight LPCM Wav file.

Ran the Wav and the DGIndex demuxed video file back theough TMPGEnc DVD Author and Bingo !!! - sound is clear and sync stays perfect all the way to the end! Happy freakin' days !!!

On a more serious note. Audio sync always seems to give me grief. What tools would you recommend for minimising hassle in future. DGIndex will remain on my HD. Similarly, TMPGenc (fed with good input files) seems to work well. Anything else I should try or even just have a copy of against the evil day the next Gremlin stirkes?

Thanks a lot - I was about to give up on this and (as so often is the case) the solution is not too hard once you have a methodical process and te right tools to use.

baldrick45

[baldrick45]

Pride goes before a fall - Or certainly before a royal pain in the ass!

The remastered DVD plays perfectly on my PC but the sound is totally screwed on my standalone player. Lots of "plinky" noises and the speech sounds like its a million miles away and being spoken by people with mud in their mouths.

FulciLives - Be a friend and tell me what sort of half assed mess I've made now cuz this has me totally confused.

baldrick45

[gshelley61]

I just had to do something similar to an existing DVD-Video from a standalone recorder that had sound on only one channel. I used VOBEdit to demux the VOB. I converted the AC3 file to WAV with PX3 AC3 to WAV Convert. Then I applied a left channel only filter (under Tools, Stereo Processor) in Nero Wave Editor to create a new WAV file that had sound in both channels. I converted the WAV back to AC3 with Headac3he. I remuxed and created a new DVD-Video file with IFOEdit. No sync problem, but it is only about 10 minutes.