Captured audio stretches over time

[dimoj]

Hi again. I've searched the forums and there seems to be many people having similar problems but I couldn't find any with replys.

When I capture analogue video with audio and watch it back the audio seems to get out of time with the vid as the clip progresses. i.e. at the start of the clip the sound is in sync but by about 30 secs or so the sound is ahead of the video and this gets progressively worse the longer the clip. I have talked to a friend and he has the same problem but has been living with it (like an embarrassing rash).

The strange thing is that on the timeline the audio and video are the same length so they should be in sync. The audio is not merely a frame or two ahead otherwise I could just bump it along a bit but it seems to be actually stretched and playing at an inconsistant speed.

Does anyone have any experience with this? Thanks.
(Premiere 6.5, Windows XP, Radeon 8500 vid card, audio captured through line-in of sound card).

 

[ddrafts]

We are having the same problem here.

We have narrowed it down to the Tapes that we were copying. In the tapes the clips have a 2 to 5 sec pause between them.

We feel that there is no tracking there so that is causing the problems. We have no solution for it.

But when we copy a tape that is over 2 hours that does not have the pauses the audio and video are in sync.

We are running Premiere 6.5, Windows 2k, and Pinnacle DV500Pro.

 

[Hiserve]

I have some long video clips. At any point I pick to play, they are in sync, but when I play the whole thing (within Preiere, or exporting it to tape) they progressively get out of sync, despite the video & audio being linked!

 

[dimoj]

Hi there hiserve

it's funny you should add to this thread tonight because just this evening I think I have found out why I am having this problem (but i don't know if this helps anyone else). About two months ago I changed sound cards and I didn't try capturing any vid for a while so by the time I did (and had this weird audio problem) I never associated it with with my sound card. My capture card is powered by ATI drivers and just tonight I discovered that in the Control Panel (windows) i could run a test to check my Capture card compatibility with my system and guess what....? My sound card failed on a test called SOUND CARD WITH CLOCK STABILITY BETTER THAN +/- 0.2%. When that happened it suddenly dawned on me that this weird audio problem started when I changed sound cards. long story short I'm going to get a decent Soundblaster 5.1 surround sound card tomorrow and I'm expecting that should fix the problem (shouldnt count my chickens before they are hatched though).

Perhaps your problem is a lame sound card too? I don't know but I'll find out about mine tomorrow!

"give peace a chance"
D

 

[dimoj]

Just to let Hiserve and anyone interested know that I did indeed install a decent SoundBlaster card tonight and YES it solved the audio sync problem! FINALLY! I will sleep well tonight!

 

[Hiserve]

Hi,

My soundcard is a SoundBlaster Audigy Platinum, so it is not 'lame' but whether there are some driver issues. Another person said it was due to pauses on the tape with no time stamp, but I timestamped the tape before I started and because I was recording a person speaking for well over an hour, the recording was started at the beginning of the tape, and allowed to run to the end.