How to adjust and sync large sound file with camera sound

[videopeter]

Hello,

I cannot solve how to adjust sound file to be synchronized with camera sound. I have sound file recorded in separate sound card and clip recorded by camera with low quality sound. Both camera clip and sound file are more than 1 hour long. Because of camera and sound card has not hardware synchronization, after 1 hour there is sound delay about second between them.
I tried two things:
1. Sync files to multicamera track. The result is that it is not functional. After analyzing it put sound sound track absolutely out of camera sound with several minutes offset. The question is if it put it correctly - if does it is also able to adjust described one second delay ... ?
2. In editing mode I tried "Time-lapse" dialog and I see on sound graph that I can enlarge separate sound track to correct one second delay. Graph shows me that deviation is corrected and spikes on both sound tracks are visually synchronized on the beginning and on the end, but when I try playback in project view I see they are not really synchronized, there is still one second delay between original camera sound and separate recorded sound track. Is possible to solve this problem with "Time-lapse" command ?

I use VideoStudio X9 Pro.

Peter

[asik1]

Have you succeeded doing so in the past?
Are both sounds are same sampling?

[weaver]

It can be that some video and/or soundframes are missing. Unfortunately it happens time to time that the missing data is corrected but causes a glitch ( lost of sync). This is common for almost all digital video and sound signals. The professionals use external synchronisation (similar to beeps) which resynchronize the both data time to time. ( you can see it sometimes also on TV when the lip sync goes for a while and it comes back.)
In our case the best way to edit the both tracks, when you recognize the first sync loss, cut one of the tracks and resync it again and continue. Usually in one hour of concert I have to do such steps max 2-3 times. I use for external sound recording the ZoomH2 either in wav or mp3 formats.

[lata]

Hi
After setting the audio sync at the beginning, does audio drift out towards the end….
You could try stretching the audio clip, with the clip selected drag the end whilst pressing Shift
You should switch to Sound Mixer to view the wave form.

There was a similar post
http://forum.corel.com/EN/viewtopic.php ... nc#p333477
Read the reply on the second page.

I believe the audio problem was because of KHZ of 4.1 and 4.8 being used
Converting one to 48KHZ seemed to cure this particular problem.

[videopeter]

Have you succeeded doing so in the past?
Are both sounds are same sampling?

Separate sound was recorded with different sample frequency - 44Khz and video contains sound with sample frequency 48Khz, but I also tried first to convert audio to 48Khz and results are the same,
so I think, that there is some deviation between camera clock and sound card clock. I did not use hardware synchronization between them.

[videopeter]

...You could try stretching the audio clip, with the clip selected drag the end whilst pressing Shift
You should switch to Sound Mixer to view the wave form.

I believe the audio problem was because of KHZ of 4.1 and 4.8 being used
Converting one to 48KHZ seemed to cure this particular problem.

Thank you for the tip. When I try to stretch audio then I can see on clip view that it is stretched and end of audio is synchronized with camera sound because I see synchronized spikes on sound graphs. But when I playback all in project view I hear that they are in original state - still about one second.
Dragging with Shift is the same like settings in dialog under Time-lapse menu command. I played also with this dialog and graphs shows that audio is a bit stretched and synchrnoized through all hour, but when playback project I can hear that they are not.
Why my audio cannot be stretched by this way ?

I also tried first to convert 44Khz audio to 48Khz and then import to project, but still there is after hour one second deviation.

[asik1]

looks like you have to cut it into sections at the quiet parts and resync.

[videopeter]

looks like you have to cut it into sections at the quiet parts and resync.

It seems that cutting into sections and resync is only solution but why audio stretching is not functional ?

[gewb]

Based on 30fps and 1 hr run time that's 108,000 frames. The one second differencial represents an error of 0.0278% which is likely within the margin of error for nonprofessional equipment (camera + audio recorder + computer hardawre + software).

You could make a one frame correction every 3,600 frames (every two minutes of run time) as that would only be noticable to the most trained/discerning eyes and ears.

Perhaps use Audacity to change the separate audio track to match the camera sound track?

Regards,
GEWB