audio and video mismatch

masterisaa

hi, this is my first time here, and my 1st time using camstudio.

i noticed that this program is so light unlike other ones... so i'm so attached to it..

but now i am facing a huge problem ... the audio doesn't match with audio... i mean NOT Delay...

at the the beginning, audio n video are "excellent", no delay and no mismatch... all good..
but a time goes... the problem starts to be "noticeable".... after two minuts about...there is a bout 2-3 seconds delay

so, i hope u can put an end for this issue

pierluigi

I have also noticed the same thing!

We are recording training sessions with human participants for an experiment, and really need the videos for subsequent review and analysis. It is quite important to have the video and audio synced! Sometimes our recordings can be 30 minutes long, and the mismatch between audio and video becomes very large.

Does anybody know how to fix this problem?

Thanks!!!

pensbury

I think it's a computer memory or resources problem. I was having the same problem till I adjusted the audio quality setting right down to the minimum (11.025 kHz, mono, 8-bit). It's still not perfect - but it's a LOT better, even for long recordings.

At least it's worth a try before rushing off to try another program which may or may not be any better.

Options>Audio Options>Audio Options for Microphone

TerryBritton

I discovered a resource at WikiBooks that explained this issue. I made a video describing how to fix it at YouTube (here it is at my blog:
http://terrybritton.com/camstudio-settings-to-keep-audio-and-video-in-sync-212/

Here is the WikiBooks entry that is relevant:

Framerates:
Capture Frames Every __ milliseconds and Playback Rate
To get the Capture Frames value, divide 1000 (1 second = 1000 milliseconds) by the Playback Rate.

For example:
By default the playback rate is 20 and the Capture Every is 50, because 1000/20=50.
A playback rate of 10 would need the Capture Every set to 100, because 1000/10=100.
A playback rate of 25 would need the Capture Every set to 40, because 1000/25=40.
If you wanted a Playback Rate of 30 frames/second, a good capture rate would be 33, as 1000/30=33.333...

Four things to keep in mind:
A higher framerate will allow for smooth playback, but will also result in a larger file size as more frames will be created.

CamStudio currently only accepts whole numbers for the options here, any decimal values will simply be ignored (eg: if you entered 33.333 for your playback
rate, CamStudio will store it as 33).

[My Note:INTERESTING!!! Is the above true???]

If you want to record video and audio at the same time, you will need to have values for the capture and playback rate with a product of exactly 1000 (eg: 100 for the capture frames and 10 for the playback as 100*10=1000). A capture frames value and playback rate that do not multiply wholly into 1000 (such as 33 and 30 mentioned in the example above) will cause the audio and video to become out of sync (33*30=990, not 1000).

A playback rate much higher then the capture setting is grabbing frames will "speed-up" or time-lapse the video, a lower playback rate will "slowdown" the playback rate.

Reference link:
http://en.wikibooks.org/wiki/Screencasting_with_CamStudio - visit for even more information.

I hope these are helpful to you and the community at large.

Terry Britton

JKEngineer

I have also had mismatches develop between the audio and the video. I fix them easily using VirtualDub, which is a free video editing software. (also available as a portable version)
It's been a while since I did it, but there is an explicit command in the menu system to make the audio and video match. It usually tells you something about the ratio needed to fix. I think it's on the menu under Video > Frame Rate.

JK

TerryBritton

I made a video and a post at my blog concerning this issue, but forgot to come back to this thread and post it here until today. Here it is!

http://terrybritton.com/camstudio-settings-to-keep-audio-and-video-in-sync-212/

Terry

Ptolemaios

masterisaa,

Try to see if this solution works for you
http://camstudio.org/forum/comments.php?DiscussionID=420&page=1#Comment_1516