Auto Gordian Knot gives delayed audio in output files

[nic2k4]

hand edit the cell which method never was described.

Mostly to verify what can cause your issue, but you can also add up the time value of empty cells to calculate the delay adjustment.

[loninappleton]

I have reviewed this thread and decided the following questions belongs as part of this process.

On the current job I have decided the only way to finish is to do my audio processing on the whole job and then cut/edit with virtual dub. The method shown previous with DVD Shrink has failed to eliminate the delay problem.

The delay problem is eliminated in my current edit save for one very frustrating thing: No matter how fine I try to edit at the beginning of Part two during a fadeout, the resulting edit invariably starts from the beginning of the job on Part two. It may have to do with a keyframe or something and I just have to leave as- is with a bit of the previous 'act' in the file.

What setting could I be missing that I cannot accurately trim my edit at the beginning? I have tried everything but Virtual Dub seems to ignore it when going to save.

I have used the Mark In and Mark Out in the usual way then saved to a new file name. Is the new edit not being saved to the new file name for some reason? After at least 6 or 7 fresh tries I get the same result with no edit produced.

[nic2k4]

Take a look at this thread.

Should add that Smart mode in AVIdemux only works with MP4 video.

[hello_hello]

VirutalDub (not VirtualDubMod) also apparently does smart cutting. It's called smart rendering under the Video menu. I've never used it myself.

[loninappleton]

VirutalDub (not VirtualDubMod) also apparently does smart cutting. It's called smart rendering under the Video menu. I've never used it myself.

Hello again,

I installed Virtual Dub from the link at videohelp here. It appears that smart rendering is a default option which is checked. I will see if I can get a result from it in Virtual Dub.

It appears that this Vdub is much newer than what I've been using. Is this because the Mod version has more built -in scripts or features most often used?

[loninappleton]

Update,

I appear to have a consistent problem now across two different edits. The same "jump to previous" behavior is happening which skips a fade out/fade in between two parts of a play.

There is a fade to black between these parts as in an intermission.

Could there be a setting in Virtual Dub which is dropping frames and looking for the previous image sequence?

Smart rendering turns itself off when direct stream processing is selected. Why it does that I do not know.

What I've seen in this is a consistent unwanted result across two projects which does not allow me to cut at that 'dark' crossfade moment in the media.

I was careful to select a frame during the fade which seems to be ignored for all my trying to place the cut there.


While waiting for a response here 'm going to go back through these answers and simply see if one of the other program selections can solve this by entering a time as does DVDShrink.

[hello_hello]

I don't use VirtualDub(Mod) myself for much besides remuxing and very basic encoding jobs, so I'm actually not overly familiar with all the differences, but I suspect one reason VirtualDubMod is used by conversion programs such as AutoGK more than VirtualDub would be the fact it can mux multiple audio streams into a single AVI. And I think it has native AC3 support. I'm pretty sure VirtualDub still requires a "system decoder" to decode that. Unfortunately though, VirtualDubMod hasn't been updating in years.

The way I understand it, when smart rendering is enabled, VirtualDub will attempt to copy all the frames it can. When there's frame dependencies missing (ie you didn't cut on a keyframe) it'll attempt to re-encode until it hits the next keyframe, then it'll start copying again. I guess you can't use smart rendering with direct stream copy as smart rendering doesn't necessarily copy everything.

I'm not sure I really understand your "jump to previous" problem. Can you upload a small sample where you have the problem when you try to edit or join it etc?

[loninappleton]

Jump to previous may be a bad expression. All I can really do is describe it verbally.

There part one and part two with a fade out fade in between. If I try to cut at the fade part what I get is the tail end of part one (just before the blackout.) On replay the tail end, fade out, fade in and part two play normally.

The Virtual Dub prog is simply ignoring any edits I made. Example. I loaded the part two with that tail end part. I used the buttons to just snip off that image and into the black. Playback gave a result as if nothing had occurred: that I had not saved the new part two as a new file name or anything and played as before.

I can't do anything else with this. It's like banging my dead against the wall. What could cause such behavior-- that of not saving an edit? I clearly had a new edit marked with a little snip off the beginning to get rid of the tail end of part one. And yet it did not save properly. This is the question of the day.

No joining and such is needed. Part one and part two only. Part two should display from the black and fade in.

I may have to abandon such editing if it is this much of a chore. I never thought simply dividing a file could be so daunting.

[hello_hello]

It sounds like you're not editing on a keyframe so Virtualdub is simply ignoring it.

Instead of trying to delete what you don't want and saving the rest (assuming that's what you're doing), select the start and end points of what you do want, and use File/SaveAs to save that as a new AVI. Or if you're doing that way already, select the start and end points of the bit you want to remove and try Edit/Delete. If you're definitely editing on a keyframe, there's no reason I can think of why it shouldn't work.

[loninappleton]

It may be that doing these edits do more harm than good for my purpose. If the final result and sync is better with no 'intermission' then that is what I should settle on.

On the next job I will go back and use the DVD Shrink method again.

What I don't understand is how I _gained_ the problem of Delays being added in the AGK part of the
authoring/re-encode procedure.

The last thing I will ask is, since we are at an impasse, is to give the steps on how to remove a delay if that is possible in an audio file.
It might have been mentioned earlier but without the details.

In other words: I have my original mp3 for working on the audio made by AGK. It shows Delay O ms.
I do my audio adjustments which involve multiple steps. Then a Delay of 130 ms or more is showing.

How can I fix the delay and do the final remux as described elsewhere in these discussions of Virtual Dub Mod? I'll assume the delay has to be fixed on the very final mp3 before it becomes the replacement for the avi audio in the Virtual Dub Mod streams list procedure.

This may be too wordy. How Do I remove a delay showing in an mp3 file?

Lastly, the other program mentioned to do the edit... can't find it right now... that one simply crashed. I do not have a green thumb for these things.

[hello_hello]

There's no reason why you can't set a delay for an audio stream in an AVI (or MP4 or MKV etc). Every so often, I end up with an encode where, for no apparent reason, the audio needs to be adjusted. It doesn't happen often but I've given up trying to work out why and just fix it.

I use MPC-HC for working out the delay required. Often it's a multiple of 40ms (given that's exactly the frame duration for PAL, and close for NTSC). I open MPC-HC, go into it's options, and under "Player" select "open a new player for each media file". Then under Player/Keys, I change the Fullscreen mouse shortcut to "Middle down". That stops the left mouse button from being able to switch in and out of fullscreen, which makes the following easier.....
It might sound hard at first but it's really easy once you've done it a few times.

Open the original video in MPC-HC and the encode in another instance of MPC-HC. If you think you know how far out the audio is, use the plus and minus keys on the numeric keypad to set the delay for the encoded version. Start them both playing. You can start and stop each one playing by left clicking on the video. A couple of quick left clicks stops it very briefly and restarts it. The idea is to sync the audio in both videos. When it's close it'll sound like there's an echo. When it's exact, the audio will produce a phasing effect as they'll cancel each other out a bit. Stop and start each video as required until that happens. With the audio synced watch the video for scene changes. If they happen at exactly the same time the audio/video sync is the same for each version. If they don't, stop the players, adjust the audio sync and try it again. Because you can see scene changes instantaneously, it's possible to get the audio/video sync pretty much exact that way. To within 10ms shouldn't be hard. When the audio/video sync matches, make note of the audio delay in the MPC-HC status bar. You might need to tap the plus or minus key to see it, so remember that'll also add/subtract 10ms from the delay you were using.

Open the encoded video in VirtualDubMod. Use the Streams/Streams List menu, right click on the audio and select Interleaving. In the window which opens you can set the required audio delay. For the record, there's also a setting in there called "interleave audio every". AutoGK muxes with that set to "interleave audio every two frames". It doesn't matter at all if you leave it at the default, but it does effect the output file size a tiny bit. I thought I'd mention it in case you wondered why the file size increased a tad after re-muxing an AVI which AutoGK originally created.

Resave the AVI using Direct Stream Copy. If the audio delay value used was negative, VirtualDub will move the audio "backwards" by the required amount, then trim what's needed from the beginning of the audio so the video and audio begin at the same time. If the delay is positive it'll move the audio "forward" in relation to the video.

If you want to do it yourself you can open MP3 audio using MP3DirectCut, trim off the required amount from the beginning (negative delay required) or add an appropriate amount to the beginning. I do the latter by selecting a silent section of the MP3 and using copy and paste to add it to the start. Resave the MP3 and you should be able to then mux it without any audio delay.

Anyway.... after resaving the AVI you can check the saved version against the original using the same MPC-HC method. One last thing.... the audio/video sync when playing vob files isn't always perfect. It should be though, if you use MPC-HC to open an IFO file rather than open a vob file directly.

I have my original mp3 for working on the audio made by AGK. It shows Delay O ms.
I do my audio adjustments which involve multiple steps. Then a Delay of 130 ms or more is showing.

If the original MP3 syncs perfectly with the video without an audio delay, but after you've filtered the audio yourself etc it doesn't.....
Logically the lengths of the audio must be different. Can you check the exact lengths of each version?

[loninappleton]

Thanks for this detailed reply. It's worth some more experimenting to get it right.

I use the J/K keyboard keys for forward back audio adjustment in VLC. The screen display shows adjustment in 50 ms increments.

For anyone who hasn't done this: Your out of sync audio can be adjusted in VLC:

Pause/stop the playback
Press J or K for back or forward audio adjust
Start playback again. It isonly good for the run of the content.

But if the mp3 has DELAY *** where * is a number written on it, shouldn't that be what is used in the Virtual Dub Mod streams list procedure? I'll open up Vdub and at least find out where this procedure is. I'm always fearful of messing things up.

I will check the lengths of what I call LEV copies (for levelled audio for voice) in Goldwave which shows
seconds plus 3 decimal places.

[hello_hello]

I use the J/K keyboard keys for forward back audio adjustment in VLC. The screen display shows adjustment in 50 ms increments.

I think that's around #27 or #28 on my list of reason why I prefer MPC-HC to VLC. MPC-HC's audio delay adjustments are in 10ms increments. Possibly at around #3 would be the somewhat inexplicable inability to pause a video playing in VLC by clicking on the video itself.
You reminded me. Using Shift+back/forward arrows with MPC-HC jumps between keyframes. An easy way to work out where they are when using a player. That's somewhere in the top 20 reasons why I prefer MPC-HC.

But if the mp3 has DELAY *** where * is a number written on it, shouldn't that be what is used in the Virtual Dub Mod streams list procedure? I'll open up Vdub and at least find out where this procedure is. I'm always fearful of messing things up.

Yeah.... DGIndex extracts the audio from the vob files and writes any delay required to the file name. AutoGK just copies the file name when converting to MP3. VirtualDubMod (or AutoGK) automatically applies the correct delay when muxing.
Sometimes though, for reasons I'm yet to discover, the audio sync still ends up out. It happened to me when converting a DVD a few weeks ago. Using my dual player MPC-HC method confirmed the audio required an 80ms delay. 99.99% of the time the system works. When it doesn't, I just fix it.

The MP3 audio.... after AutoGK created the AVI did you confirm the sync was okay? Or did you just convert and remux it? It might pay to check. It mightn't be anything you did, it might have been out in the first place..... for some reason.

[loninappleton]

My file size for video on original and LEV are exactly the same.
However I believe that I do not know how to handle the edits for all of my trying. Using the Mark In and Mark out to either save or edit out both fail.

What are the exact steps? How can I accurately preview the results? And is there a way to do this through the drop down menus rather than that poorly marked button bar at the bottom? My mouse hand physically hurts from trying to position the device on a special line to find out what the buttons are for.

The result I get from using Mark in and mark out and as it is highlighted is:
"Lon I don't want to do that-- here it is from the beginning again.' This has been going on for days.

[hello_hello]

If you use the navigation bar to jump to the beginning of the video (if need be), use the mark-in button to set the start point, then click on the right keyframe button (there's two with a pic of a key on it) that'll jump you to the next keyframe. Use mark-out and then Edit/Delete to remove the section you marked, and you should be able to save the rest as a new AVI with Direct Stream Copy.
If you're removing a bit from the end the method is the same, except you'd set the "end edit point" at the end, use the left keyframe button to jump back to the previous keyframe and set the "beginning edit point" there.
I thought you'd be using VirtualDubMod to edit this way for a while now?

[loninappleton]

It's worrying me that I am wasting your time with these kind of questions. And yes, all that has been said has been working in previous projects. For that I am grateful.

The keyframe jump back or forward seems to be where my problem is. I'll not belabor this further and simply abandon the edit on this project. The technique with DVD Shrink works better and is understandable and has an easier interface to work with (from the standpoint of hand strain which I mentioned.)

And I don't know if this is helpful to other users. Virtual Dub has been around a long time so It's my problem.

There is odd behavior here though. I tried another AVI edit program. It is called AVIdemux (open source GPL). In that one, stepping through
where the blackout is simply skipped over it. It displays in playback and then cannot be isolated
for an edit. All I can say is it must be quirk in the source.

Thanks for trying. If other problems crop up in the DVDShrink edit procedure i'll open this thread again. There may be a workaround in the future.