audio, out of sync

Thanks for the replies, I especially appreciate all the info from dlanor. So it turns out that most of my files actually have ac3 audio... Would they still be affected by the same timing issues that vbr mp3 can pose?

I did further testing and the audio seems to be off by about the same amount throughout the movie, perhaps it's rather that the audio offset controls don't allow a fine enough degree of adjustment to sync it dead on.

Maybe SMS could add the ability to adjust audio +/- offset by .10 of a second instead of .25 in a future update?

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Originally Posted by qwerty159

Thanks for the replies, I especially appreciate all the info from dlanor. So it turns out that most of my files actually have ac3 audio... Would they still be affected by the same timing issues that vbr mp3 can pose?

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No. AC3 is CBR only, as far as I know anyway.

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I did further testing and the audio seems to be off by about the same amount throughout the movie, perhaps it's rather that the audio offset controls don't allow a fine enough degree of adjustment to sync it dead on.

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If the sync offset is constant, then a minor adjustment at the start of the movie (using the controls of SMS) should suffice.

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Maybe SMS could add the ability to adjust audio +/- offset by .10 of a second instead of .25 in a future update?

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Perhaps, but that's up to EEUG (as for all SMS changes).

Anyway, even with .25 sec resolution, you can always pinpoint any constant offset to within one 8th of a second (.125 sec), which should be fairly acceptable as-is.

Best regards: dlanor

After further testing, it seems just about every movie starts off at -.125 off and slips to around -.300 by the end of a 90 minute film. I usually end up sliding it back by .25 every 10/15 minutes to keep it roughly sync'ed. This is regardless of audio codec, so maybe it could be the usb connection? And yeah, I guess .25 increments work well enough.

dlanor, can you give us a link to a VirtualDub tutorial? I con't even fint the convert button! And I have no ideea to w/ video format I'm converting!

EDIT: NVM, I found this tutorial, but if you have a better one, pls post dlanor! :)

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Originally Posted by solidus27

dlanor, can you give us a link to a VirtualDub tutorial?

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Sorry, but I've never used any, so I don't really know what's available.

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I con't even fint the convert button!

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There is none. For normal single-file conversions you start by opening your source file and then select the various encoding options for video and audio, finally you go to the 'File' menu and use the command 'Save as AVI...'

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And I have no ideea to w/ video format I'm converting!

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Obviously not, since you don't know the program well yet.

But it's not all that hard, really. The only 'container' supported is AVI (so no MKV complications etc), and the video encoding is chosen simply by using the menu command 'Video'/'Compression...' which opens a codec selector, where you also have the option of further configuring the chosen codec. Normally I just choose the XviD codec and configure it to use a suitable bitrate. Around 1000 kbps is fine for normal TV shows/movies, and I never bother with more than a single pass (multi-pass is horribly slow, though it does produce more efficient packing).

But most of my own conversions are only for changing the sound track, so I use the settings 'Video'/'Direct stream copy' (to avoid changing the video) and 'Audio'/'Full processing mode' (to allow tweaks to the audio track), after which I choose the 'Audio'/'Compression...' command to choose the MP3 codec and configure its settings. At this point it may also be a good idea to save the conversion settings for future use in job control, by using the command 'File'/'Save processing settings...'. And then all that remains is to use the 'File'/'Save as AVI...' command to choose where to save the result of the current conversion. And that starts the conversion process.

Once you have suitable processing settings saved to a VCF file, and have a batch of video files that need similar conversion, then it becomes much more convenient to use the job control feature, as I described in an earlier post.

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EDIT: NVM, I found this tutorial,

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Unfortunately that is a tutorial on video capture, not video conversion, but perhaps it may still help you familiarize yourself with the program. But I really think you should try to find another.

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but if you have a better one, pls post dlanor! :)

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I'm afraid not. But I'm sure google can find some.

Just entering: "VirtualDub tutorial" (without the quotes) into the google search box brought up tons of hits when I tried it, though I can't say which of them are any good.
(The total number of hits was rounded to 241,000, so you'll have to pardon me for not checking them all out. :D)

Btw: VirtualDub itself does not contain any codecs, so it can only use whatever codecs you have installed by other means. (You probably already have all you need though.)

Best regards: dlanor

Thanks alot dlanor. As always, very helpfull!

After watching a bunch of movies over the weekend, I've come to terms with this and have found that simply pausing the movie for a second every 20 minutes or so will keep the audio roughly in sync.

So if I start out at -.125, I can usually just stay there if I pause a few times. The audio issue is not as bad as I initially thought and seems to have no relation to the audio encoding in the movie files. Try this approach before re-encoding your collection if you're having problems. It's not perfect, but it's close enough that an average person probably wouldn't notice unless they were looking for it.