Audio Drop Out fix status?

[DVD Maniac]

I am not getting replies on the "main" thread for this topic hence this post. I have experiemced the audio drop out problem on roughly 3 out of 4 attempts with Rebuilder and so I am very eager for a fix from jdobbs.

My successful attempts all seem to have one thing in common - they are all episode type discs which originally appeared very odd. Thinking more about it though I have checked back on them and they are ALL DD2.0 audio as opposed to the usual DD5.0 or DTS. All the failed attempts have been with movies with the more typical DD5.0 / DTS. I am no expert but this indicates to me that it is very likely to do with the way that Rebuilder is re-muxing the encoded .m2v's and original .ac3's and that 2 channel audio is not affected.

I am hoping that this is high on the fix priority list as I have a number of movies that require heavy compression queued up waiting for this fix. I really do not want to resort to lower quaility encoding methods for these but will have to if this fix is a long way off - can you give some indication of when to expect a solution?

[Noah]

Yes, this would be priority #1 for me as well. I don't think jdobbs would disagree with that, given his most recent post (http://forum.doom9.org/showthread.php?s=&postid=517419#post512897) to the "Still Getting Stutter" thread, it sounds like its more of time issue than anything taking precedence over this.

Has anyone tried what he suggested here (http://forum.doom9.org/showthread.php?s=&threadid=75848&perpage=20&pagenumber=7#post511868):
If you took one of the offending VTSs and ran it through IFOEdit, then reintegrated it (using IFOUpdate) I think you'd see the dropouts go away.
If not, I'll give it a go, assuming it will be helpful in tracking this bug down.

[jdobbs]

I can tell you that I use DD5.1 on every DVD I backup -- and I've only gotten audio dropout once on only one disc that I can remember (and I've done a LOT of discs). So trying to fix the problem is difficult -- I can't even find the one example I had so I can try to repeat it.

It would be nice if someone who is experiencing the problem would try fixing it with IFOEDIT -- then I could at least have something to grab onto. But in the meantime, since no one seems to have the time to try it, I can't even confirm that this is a problem.

[Joergen]

Same here, I always use DD5.1 (though never DTS) and havent had any audio drops on tens of discs. Not saying its not possible but like jdobbs said its impossible to debug when there is nothing to work with.

[Noah]

I believe DVD players are a complicating factor in this issue. Some seem to gloss over this problem better than others.

[Skinleech]

Originally posted by Noah
I believe DVD players are a complicating factor in this issue. Some seem to gloss over this problem better than others.

I agree - all my DVD watching is via pc, and I have no problems with drop out on 2.0, 5.1 and DTS. I've been using RB since the first few betas, and I've never expereienced any major problems.

[Joergen]

The player, burner used, media used, burning speed, burning software used etc etc is a factor. But I however have tested several RB discs on 5-6 different brand of dvd player without problems.

I have had audio dropouts on one Pioneer player with DVDShrink output and shrink is considered "flawless" by many.

Unlike almost everybody, I read-test each disc I burn in a regular Lite-On DVD-ROM, which is closest to your average dvd player, while your burner might read anything.

[DVD Maniac]

It would be nice if someone who is experiencing the problem would try fixing it with IFOEDIT -- then I could at least have something to grab onto. But in the meantime, since no one seems to have the time to try it, I can't even confirm that this is a problem.

jdobbs, what exactly are you asking for here? I am very happy to help but need some guidance on what you need. Are you reffering to washing the offending titleset through IFOEDIT with a vob strip? I am aware this can sometimes fix dodgy timecodes or audio sync problems but don't know enough about what Rebuilder is actually doing to know if this is a sensible test to run??????

[Noah]

Originally posted by Joergen
The player, burner used, media used, burning speed, burning software used etc etc is a factor.
No, I don't believe any of that's relevant except the player. We need to separate what I would call "disc quality" issues with data compliance issues. The former being the burner/media/burning software and the latter being audio remuxing and fault tolerance of hardware players.


The audio drop-out issue is a data compliance issue. I don't believe disc quality can cause a player to lose the audio stream while having no impact on video. The correlation between audio drop-outs and chapter breaks further belies any connection.

But I however have tested several RB discs on 5-6 different brand of dvd player without problems.
If your testing falls short of watching entire movies in multichannel audio using a digital connection to an outboard decoder/receiver, I'm not sure you'd encounter this issue at all. That's not to say this is a trivial issue.

[DVD Maniac]

If your testing falls short of watching entire movies in multichannel audio using a digital connection to an outboard decoder/receiver, I'm not sure you'd encounter this issue at all. That's not to say this is a trivial issue.

Noah,
That's a very good point. ALL the attempts that I have considered as "flawed" results have only resulted from watching the entire backup on either of my set-tops with external decoders. The drop-outs appear random in that there is no correlation to chapter points or complex video scenes. Tests with the same sources on Shrink or Recode with the same media and player combinations result in no audio drop out problems (BTW - I always use high quality blanks) leading me to believe that its a Rebuilder issue.

If someone will indicate the exact IFOEDIT tinkering that needs trying I will gladly accomodate

[Noah]

Hmmm, that's curious that your drop-outs are random. Most, but not all of mine are at chapter breaks.

I'm not too knowledgeable about IFOEdit or IFOUpdate, but I think what he's basically suggesting is to demux and remux using different tools to see if that removes the drop-outs. OK, I just realized I don't exactly know what he's asking for either. ;)

If we can get a clarification, I'll certainly test it out as well.

[jdobbs]

I always backup DVDs the same day I buy them and then watch the backup -- so I watch them end-to-end. No problems.

You don't have to demux anything to test IFOEDIT.

1. Get IFOEDIT
2. Run IFOEDIT and select the IFO for the offending VTS.
3. Select VOB EXTRAS.
4. Make sure all that is clicked is:
- Correct VOB-Unit...
- Correct original IFO files
- Adjust VOB Unit pointers
- Adjust audio/subp point
5. Click OK and run it.

Then burn a DVD-RW and see if the audio dropouts go away. If they do, then I know I can start looking for differences. The reason I mention this is that someone mentioned that this might work in the past.

[Joergen]

Originally posted by Noah
If your testing falls short of watching entire movies in multichannel audio using a digital connection to an outboard decoder/receiver, I'm not sure you'd encounter this issue at all. That's not to say this is a trivial issue.

That's right, I nor none of my friends use digital connections for the amplifier. But I did suggest a few days ago (in another thread) that everybody having drop-outs must be using digital outputs, as it is said to be a problem with DVDShrink also.

[jdobbs]

I use digital connections exclusively. I don't have anything connected to the analog out jacks... still don't see it.

[DVD Maniac]

You don't have to demux anything to test IFOEDIT. 1. Get IFOEDIT 2. Run IFOEDIT and select the IFO for the offending VTS. 3. Select VOB EXTRAS. 4. Make sure all that is clicked is: - Correct VOB-Unit... - Correct original IFO files - Adjust VOB Unit pointers - Adjust audio/subp point 5. Click OK and run it.

OK, this is the method I suspected you were reffering to. It is a recommended step after doing any vob replacements using tools like Menu edit. Its supposed to cure problems with not being able to scan properly with set-tops. I will give it a go with Master and Commander which has been my most problematic source to date.

jdobbs - do you have the PAL version of this movie so we can compare results?

[jdobbs]

Sorry, but no. Everything I have is NTSC.

[DVD Maniac]

Will the before and after .ifo's be enough for you to trace the differences?

[jdobbs]

Originally posted by DVD Maniac
Will the before and after .ifo's be enough for you to trace the differences? All I really need is a confirmation or not that it actually fixes it. I can take it from there. I need to know definitely, though. If I start digging through VOB sectors I'd like to be pretty sure that the answer is in there somewhere.

[DVD Maniac]

I ran the following test -

Title : Master and Commander (PAL - Interlaced)
Audio : DD5 and DTS (Source), DTS (Output)

Originally I did this with Rebuilder versions 0.50 through 0.52 and was getting Audio drop out at random (but consistent) points through the film.

I now ran the same backup with 0.54 and created two +RW's to watch -

Disc 1 - Rebuulder Result
Disc 2 - Rebuilder result, with the main VTS run through ifoedit and remerged.

I was surprised to find that ALL the audio drop outs had gone from Disc 1 and so I did not have to jump to Disc 2 to see if there was a difference. This may of course just be a one-off so I am going to do a few more to make sure.

Has there been any changes in the re-muxing code from v0.52 to v0.54 which would explain this? (I did not see anything in the changelog which would indicate this)

[Noah]

Why don't you try this on a disc that already stutters? I.E., rip a stuttering VTS, apply the fix, and burn. That's what I'm working on...

[Joergen]

Then again, running in circles, standalones might read the +RW better than whatever media you used before.

A friend of mine had audio dropouts on the R2 version of Master and commander using the DD5.1 track, this was with a DVDShrink backup! It's prolly a good test disc.

[Noah]

Originally posted by Joergen
Then again, running in circles, standalones might read the +RW better than whatever media you used before.
Regardless of how well it reads the disc, its either going to have audio dropouts or not have audio dropouts as a result of other factors.

[DVD Maniac]

Why don't you try this on a disc that already stutters? I.E., rip a stuttering VTS, apply the fix, and burn. That's what I'm working on...

I deleted all my previous results with audio drop-out (assume you mean this and not stutter - which jdobbs already defined as a different problem)

Then again, running in circles, standalones might read the +RW better than whatever media you used before. A friend of mine had audio dropouts on the R2 version of Master and commander using the DD5.1 track, this was with a DVDShrink backup! It's prolly a good test disc.

My test was meant to be media, burning sw and player "neutral", ie two versions burnt using Nero on the same DVD+RW brand discs. I had the audio drop problem on the same +RW media previously so these factors can be treated as consistent across the test. I don't want to jump to any conclusions until I run at least three more tests but my initial thought is that changes in the Rebuilder remux code since v0.52 may have fixed the problem - only he can advise on the validity of this claim!

[gizzin]

so if i already burnt the output i could fix the audio dropouts, by copying it to the hd and demuxing it with ifoedit? does this actually work?

[jdobbs]

Originally posted by gizzin
so if i already burnt the output i could fix the audio dropouts, by copying it to the hd and demuxing it with ifoedit? does this actually work? You don't demux -- you use the vob tools to correct VOBU pointers. It still remains to be seen whether it works.

[DVD Maniac]

I got audio drop on my last backup which I am attempting an ifoedit fix as I type this. Will report results in 30 mins or so

[DVD Maniac]

My last backup was a set of episode discs which I used Rebuilder for and took for granted that they would work OK based on previous experience......

On watching the first disc and first episode there was severe audio drop from the word go. I had deleted the Rebuilder results on my hard drive so I copied the disc contents back to hard drive and ran the ifoedit vob strip process (retaining all vob's of course), rebuilt the titlesets, ran correct VTS sectors and burnt on to a +RW.

Result - Drop-outs are still there and as bad as the first result :(

This is very annoying, especially as I now have 5 trashed +R's and don't know if I can trust Rebuilder with any title now...

:mad:

[jdobbs]

There has to be something different about your configuration. As I've said before, I've only gotten one dropout in lots of discs... especially if you get the same thing with the IFO "fix VOBU pointers".

Well at least I can eliminate the VOBU pointers as the problem. Could you try something else for me? Demux the offending audio track from the original and the copy and see if they match. Maybe it's something as simple as missing packets.

I wouldn't start slamming Rebuilder yet... I think this may be just centered on a few users.

[DVD Maniac]

First I am trying to run the Rebuilder result through Shrink at 99% compression to see if that fixes it. I will also try the demux as you suggested.

Sorry if I came across as slamming your app - its still a great innovation and I am certain these minor flaws will be ironed out soon. Its just frustrating when you waste multiple discs like this!

[DVD Maniac]

OK, I think we have the symptom identified (but not sure what the route cause is).

My Shrink test made no difference.

I them ran the demux that you suggested, here are the file sizes of the two audio streams before and after the Rebuilder processing -

Audio Stream Label 80 (DD5)

Original File size 446,801,152 Bytes
Rebuilder output 446,800,029 Bytes

Audio Stream 81 (DD2)

Original File size 223,404,032 Bytes
Rebuilder output 223,400,576 Bytes

So it looks like Rebuilder is dropping some audio packets in the final remuxing stage which would certainly explain intermitent audio drop out (or else there would be sync drift which does not happen). I am not sure how you are maintaining sync with this final process but it looks like the dropped packets are being traded for audio / video sync

Hope this helps you track down the route cause!

[Noah]

I don't think <4kb is enough to attribute so many dropouts to missing packets...

[the-warriners]

I think you will find that is actually 446mb

[jdobbs]

I don't think so... that would be larger than the entire audio stream.

[jdobbs]

Originally posted by DVD Maniac
So it looks like Rebuilder is dropping some audio packets in the final remuxing stage which would certainly explain intermitent audio drop out (or else there would be sync drift which does not happen). I am not sure how you are maintaining sync with this final process but it looks like the dropped packets are being traded for audio / video sync Actually sync is easy -- each packet has a SCR (and PTS) that says where is should be temporally and I use that to determine what point it should be inserted in the stream.

Was there only one drop on this test? It looks like a single packet was dropped (each packet is < 2K)

This helps a lot. Thanks.

[DVD Maniac]

The data I posted was from a Movie that I did last night (Open Range) which I watched for the first ten minutes and heard two brief audio drops (difficult to judge exactly how long, say 50-100 ms each).

Some simple maths shows that would match the the % difference in audio stream byte size (assuming these were the only drops).

The more I think about it, this MUST be an indication of the problem. If the audio stream is meant to be left untouched during the remuxing stage then the demuxed streams from original and processed titlesets should be EXACTLY the same size should they not?

[jdobbs]

Interesting. Open Range is one of the movies I've done over-and-over, I keep it on my hard drive for testing. I've never experienced an audio drop out.

[Joergen]

But jdobbs you have the R1 version and DVD Maniac prolly the R2 version? So it's not comparable.

Not to mention there are probably 4 or 5 different versions of an R2 release (nordic, dutch, ger/fra, spa/por, ita, eng)

[jdobbs]

Roger that.

[jdobbs]

I guess this is a good time to ask... is anyone getting consistent audio dropouts on anything other than PAL? Remember -- there are lots of reasons why you might get an occasional audio dropout (the disc, the player, the digital player, layer breaks), so the key word here is "consistent".

[DVD Maniac]

Just to confirm I have the R2 PAL version of Open Range

[Noah]

Originally posted by jdobbs
I guess this is a good time to ask... is anyone getting consistent audio dropouts on anything other than PAL?
Yep...consistent dropouts in NTSC, most at chapter breaks.

[jkbauer]

Hello. I am new to the RB world. I am attempting to backup one of my dvd box sets (NTSC region 1, 2.0 dolby). On my first attempt, I experienced an audio sync problem. I have yet to burn a disc, only working from the HD at the moment.

I used Shrink (or Recode) to compile (@100%) the data/episodes that I ultimately want on a disc. I then use RB to encode, following the setting guide provided (CCE SP 2.66+, 3 pass). I did not watch all the episodes from end to end. I randomly chose areas to watch. The audio sync problem occurred at a chapter break. The VTS files (title sets) before and after this problem title set seemed ok. I double checked the original files (encoded by Recode) and the audio was fine.

Unfortunately, I deleted the RB-encoded files before finding this thread. I am currently re-encoding with RB using the same files. Hopefully, the problem will go away. If not, I will try to run the files through IFOedit as suggested to see if that helps. Will report back to see if this is really a random problem.

[DVD Maniac]

This is a real long shot but I just wanted to run it past everyone, particularly Mr dobbs. Usually before feeding the source files to Rebuilder, I will do some Title stripping and/or menu vob shrinking / stripping. I do NOT use programs like DVDStripper which I find tend to be slower than what I can achieve with some manual work with Ifoedit & Menuedit and I am never certain that unstripped Title's or Titlesets are left "clean"

In the case of the lost packet Title data I posted, the Titleset of the main movie was completely untouched, not even the menu was altered. So I am confident that this should not affect the end result of the encoding process that Rebuilder does with CCE. However, I wanted to make sure that this is not in some way affecting things.

[DVD Maniac]

I just demuxed the audio streams from another movie I did with Rebuilder but have not had a chance to watch yet. The audio stream byte sizes are IDENTICAL before and after Rebuilder processing which suggests that there will be no audio drops on this. I will watch this later and see if the audio packet loss theory holds good!

[jkbauer]

From my earlier post -

I re-encoded the files using RB and the audio sync problem occurred again at exactly the same chapter break as the first time. I processed the problem title set in IFOedit and that did not solve the problem.

Just to satisfy my curiosity, I am attempting to remove the chapter break using IFOedit and then encode in RB to see if that changes anything.

[DVD Maniac]

The movie I reported as having identical Audio stream size before and ater processing has audio drop out on it from the word go.:devil:


Looks like its back to Shrink or Recode for me for the time being as I am getting this problem at least every other backup. I just hope jdobbs can fix the problem as I really like the video quality output it produces with CCE.....


I just don't understand it :confused:

[jdobbs]

Neither do I. Almost no one is getting this. It seems to be centered on just a small group of users.

[DVD Maniac]

Noone has commented on my earlier post :

This is a real long shot but I just wanted to run it past everyone, particularly Mr dobbs. Usually before feeding the source files to Rebuilder, I will do some Title stripping and/or menu vob shrinking / stripping. I do NOT use programs like DVDStripper which I find tend to be slower than what I can achieve with some manual work with Ifoedit & Menuedit and I am never certain that unstripped Title's or Titlesets are left "clean" In the case of the lost packet Title data I posted, the Titleset of the main movie was completely untouched, not even the menu was altered. So I am confident that this should not affect the end result of the encoding process that Rebuilder does with CCE. However, I wanted to make sure that this is not in some way affecting things.

I really don't think this is a factor, but I not the expert here....

[Joergen]

Originally posted by DVD Maniac
getting this problem at least every other backup.

I have to again say that I've done roughly 20 different backups of PAL discs, of all sorts and never had audio delay. I once thought I had, but it was an old western with dubbed english and all the sound fx were in perfect sync :P

So far my (very few) problems have been of a consistant and globally replicable sort, in this order.

1. hundreds-of-segments bug (fixed)
2. button over video bug (fixed)
3. 16:9 sub bug (fixed)

I wish you'd do some further testing DVD Maniac, perhaps set up the tools on another PC from scratch.

[gizzin]

Fix Them Audio Dropouts, Ill send you more money $$