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Knightron 07-01-2013 05:54 PM

avi file, audio out of sync
 
Hello. I've recently purchased a new tv, and it supports usb playback, so i'm in the process of ripping my dvds through k3b to avi files for playback through usb. All has been going well, except last night, one of my disc rips had the audio out of sync. I have seen this before in some pirated dvds. This is extreamly annyoing to me, and i refuse to watch a movie in that state. I was wondering if it's possible to place the audio back in sync with kdenlive, or even rip it again with different settings to get the audio right?

Thankyou.

parnmatt 07-02-2013 03:46 AM

If you're just going to be using VLC, going into the preferences, and Showing All preferences/advance mode etc., under the audio there is an Audio Desynchronisation Compensation, I believe it's in milliseconds.

I've use it a lot when the audio was about half a second out, and other times when it was a full 10seconds out.

It is a lot of trial and error; and sometimes audio is out of sync at different rates throughout the video, due to how it was encoded.

This method is only for a constant shift in audio, and is a temporary 'fix'.

Just remember to set it back to 0 when you want to watch something again later :D

David the H. 07-03-2013 01:05 PM

A more permanent fix would be to do the same thing with a multimedia editing program. I've always had good experience with avidemux. Just keep the video and audio codecs on "copy", set the output format to be the same as input, and set the audio shift feature as needed. Again, though, it does involve some trial and error to get the sync right.

There may also be other problems that need more work, such as audio drift, where it starts out ok but gets increasingly out of sync. In those cases you should generally demux the audio from the video, edit the audio separately in something like audacity or sox so that it perfectly matches the length of the video, then recombine them.

I've also had videos that were assemblies of shorter videos, and some of the sections were ok while others were out of sync. The only option then is to completely disassemble the chunks and fix them separately.

Finally, I'm not sure about ripping, but there may be some settings for audio sync buried in there somewhere that you can try. Framerate differences between the input and output can also be a factor, I believe.

timl 07-03-2013 06:59 PM

I have this problem also. This post spurred me on to do something about it. I like David The H's proposal for a permanent fix. Last night I was trawling around for solutions. I came across this using ffmpeg:

http://alien.slackbook.org/blog/fixi...c-with-ffmpeg/

The only problem with this is accurately defining the time at which audio lags. Now I need to dig out a video which isn't synched so I can test it out.

Knightron 07-03-2013 07:18 PM

Thanks for the tips guys. Unfortunately parnmatt your solution is not what i'm after. I would like a permanent fix. I also am not using vlc on my tv.
David the H, what you have described sounds exactly what i'm after, and is quite detailed thank you.
timl, thank you as well, i checked out that link and any info from Eric is usually extremely helpful, thank you for showing me that.
I am a little short for time at the moment, but with all that info, i'm pretty sure i'll be able to fix the file. Thank you guys for the help.

timl 07-14-2013 06:31 PM

Hi Knightron, any joy with this?

Cheers

k3lt01 07-14-2013 06:51 PM

I've had the same issue a few times Knightron but all I ever do is stop the payback get out of the drive totally go back in and start again. I've seen it happen on DVDs through DVD players as well. In my case it is not the ripping that is at fault it is a momentary glitch in the device playing the ripped file.


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