Audio help : Unsync'ed Audio at 75% through Video

[Bravo]

I need some help.

About 70 - 80% through any video clip i've done, the audio becomes unsync'ed with the video stream. Aside from the "-79ms Delay" option in Gordian Knot, i cant think of a way to fix this. The audio is perfect up until 32 - 35minutes of a 41 minute video.

Im running the 28.5 version of GK, using XviD (last stable release), and a 64kb/s Constant MP3 stream. The total file size comes out to about 250 - 260mb.

Any ideas? Fairly desperate at this point as the files have been sitting on my HDD for the last 5 days :(

[killingspree]

hi,
your problem is most likely connected with the low audio bitrate you are using. perhaps you'll want to try a higher bitrate of at least 128 kbit, which is generally recommended anyway.

iirc the audio is resampled at such low bitrates and therefore the audio sync is lost!

hth
steVe

[Bravo]

Audio bitrate isnt a problem. I've encoded the same episodes using DivX 5.0.4 Pro without problem. I think the Xvid Codec is dropping frames. Will try it back with DivX 5.0.4 and see how it goes.

[killingspree]

hmm well in this case, please tell us your computer specs aswell as your exact xvid settings!

steVe

[jggimi]

Encoding audio below 128kbps has a known problem (and a known circumvention). From the Gknot Info tab:- audio-bitrates below 128 (in lame) can cause sync-problems (and sound terrible), because lame is automatically downsampling to 32 or even 22kHz. i highly recommend to use 128 or 160 and nothing else. to avoid downsampling you have to add "--resample 48" to your lame commandline options if you encode at low bitrates.

[Bravo]

Originally posted by jggimi
Encoding audio below 128kbps has a known problem (and a known circumvention). From the Gknot Info tab:
Thanks. Will give us a whirl (or get off my ass and learn OGG format :D)