I'm amazed that after all these years of Non-linear computer editing we still suffer from loss of lip sync in some form!
I remember my first venture into DTV using a Diamond CrunchIt card (remember those!), a great MJPEG capture card for it's day, but it suffered from loss of audio sync when playing back a 15-20 minute movie.
The DC30+ apparently solved the problem by having a sound card built into the capture card - The theory was good, but again, in practice still reports of sync troubles!
Having watched these and many other forums on video editing over the last couple of years I see that the age old problem of lip sync still crops up.
Computers are more powerful, faster drives, better software, bigger RAM, and everything more compatible, yet it's still there - Audio sync or loss of lip sync!!!
Was it, Is it, the capture card hardware, the editing application or the operating system causing this annoying problem?
It would appear that, despite several hints, tips, trials and errors, it's still around!
I'm not "having a go" at any manufacturer of software or hardware, just getting this small but annoying niggle off my chest, and to see what others experience has been.
To put my faith back into capture cards, is there anyone who can HONESTLY say that they can capture more than an hour of glitch free video, edit, then playback for more than an hour without the slightest loss of lip sync by the end!(everytime!)
Please prove me wrong...
And for those new to editing on a PC, you may not have had a chance to experience the joys of audio sync problems, but now we have a new generation of "loss of sync" troubles.. Converting files for VCD, DVD, copying DVD etc.. Yes, sound sync problems appear to be rising again!!
Is there really no cure for this phenomenon - Maybe we could make a movie about it - Call it "A Nightmare on Sound Track Sync Street", but if we did it would probably look like a badly dubbed foreign movie, with the lip sync lost after the first 10 minutes!
That's it, I'm done, what do others think?
Mark
Haven't had any problem with audio sync since version 2 of the DV500 drivers... sorry.
I do recall wanting to destroy certain things when i first dabled in NLE with a Miro (don't think it was even pinnacle then?) DC1. Still got it kicking around somewhere.
While audio sync was a problem with the DC1, that was only after you got premiere (version 1) to save the capture settings for long enough for you to open the capture window, convince windows that you really did have the driver installed, and then remember to untick the "loop through" box on the DC1 settings window... audio sync was the very least of our problems back then!
other mark.
Hi
As I understand it the problem lies in the AVI standard - which is basic in the extreme - ie there is no attempt to lock the audio data to the video stream...
Its the same with the DV standard - the audio is 'unlocked' and the sample rate frequency is allowed to deviate considerably (and did/does in some Canon DV cameras for instance).
Sony solved this by introducing DVCAM, where the audio sample frequency is exact, and locked to the video data stream.
However software for NL Editing is very variable in how rigidly it adheres to proper locking of the audio data stream.....
When you were using your dodgy Diamond/Miro/Fast cards I was getting perfectly locked audio for as long as a Premiere timeline allowed in v4.2 (an hour). But I was using a $10,000 Radius Telecast card in a Mac which locked everything to its own crystal-sync timecode generators. (No I didn't actually pay $10K - I went to work as a DV consultant for a dealer in order to get a massive discount!)
However you've got to admit its a damn sight easier to correct loss of sync in a NLE than in the old tape-to-tape days....
Regards
Thank you PaulD, your explaination of the AVI and DV formats on why we get loss of sync was most welcome. It's the first time someones actually mentioned the method of video/audio recording formats.
I think this subject will always be a case of some people will never suffer others will tear their hair out!!!
Lip Sync.... AaaaaaHHHHHH!!!
Not sure if this helps contribute to this thread.
I found that if I encoded MPEG2 with the MPEG2 audio at 384Khz (default in both TMPGenc and CCE Basic) the was a noticable sync time lag of approx (I think) 3 seconds but I discovered that by auio encoding at 192Khz the sync was spot on 
NB I tried 224Khz andd the was approx. 0.5 seconds variance.
As I say HTH
I use an AV MASTER....never had a problem and do plenty of 90min+ movies!!!!
never had a lyp sync problem
have used miro DC30+,
canopus DV Raptor, AVID express,Matrox Digisuite, pinnacle Edition and DVstorm2.
i thought the audio was locked once the video was digitised.
[This message has been edited by Mad_mardy (edited 31 March 2003).]
I used to suffer lip synch probs when using MSP 6.0 (With Pyro card) but since upgrading to 6.5 they seem to have gone away.