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Video audio playback is slower than the original?
hello folks
i’m a complete noob at this, but am enjoying the process of putting together my first music video for my band using Sony Vegas Pro 8.
we shot footage, using two unsynced cameras, of the band miming to the songs off CD. i then used a demo of Corel VideoStudio to capture the footage before deciding that it was way too basic a program for what i wanted to do and, after trying demos of a bunch of other software, decided that Vegas was right for me.
the problem i’m having is that even though we were miming to CD audio (ie digital – not tape, no possibility of it playing back at a different speed), the audio, and video, recorded by the camera mics is a lot slower than the CD audio we mimed to. so that when i edit the footage it drifts noticeably out of time with the imported CD audio track within 3-4 seconds.
this forum has been a wealth of info on other puzzling aspects of video editing so far, but i haven’t been able to find anything specifically addressing this issue using the search function.
i’m going to try and speed the video playback up to match the imported CD audio, but i’d really like any ideas about how this might have happened – and how to avoid it happening in future – and if anyone has any other suggestions to match the video to the audio i’d really appreciate them.
cheers
g
http://www.revolutionstudios.com.au
Sydney, Australia -
2 Replies
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> i’m going to try and speed the video playback up to match the imported CD audio, but i’d really like any ideas about how this might have happened – and how to avoid it happening in future
This happened because the crystals in the clocks that are in cameras and CD players and audio field records are all just a little different and don’t stay in sync. To do this properly, you would need very expensive equipment that uses a common external sync source. So what you are doing is very common and I do this all the time.
> – and if anyone has any other suggestions to match the video to the audio i’d really appreciate them.
I would do exactly as you are doing, leave the CD audio as the master and sync the video to it using Ctrl+Drag to stretch. Here is my workflow:
- Place both video+audio and CD audio on three tracks above each other (Trk1: Video, Trk2: Video Audio, Trk3: CD Audio)
- Visually line up the beginning of the song in both the video audio and CD audio so that they start at the exact same time (you will need to zoom in on the wave form)
- Open the CD audio in the trimmer and drop a marker on every measure. This creates embedded markers in the media.
- Then open the video with audio in the trimmer and drop a marker at every measure creating embedded markers (you now have markers to serve as visual indicators of the “drift”))
- Now back on the timeline, split the video at each marker (you will have one event for every measure of the song).
- Finally Ctrl+Drag the edges of each video event to match the embedded marker in the CD audio for that measure (optionally, you could use the Promote Media Markers script on the CD audio to create timeline markers to “snap” the video to)
You have now time-stretched the video to be “measure accurate” which should be close enough for most time drift. This is the quickest way I have found for matching CD’s to live performances. If you have a script tool like VASST Ultimate S Pro, it gets ever quicker because Ultimate S Pro can extract media makers and split the video events for you with one click.
~jr
http://www.johnrofrano.com
http://www.vasst.com -
many thanks for your help John. i’ll check out that script too.
cheers
ghttp://www.revolutionstudios.com.au
Sydney, Australia
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