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Re-Compressing Sorenson 3 Quicktimes

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BrAd S
Re-Compressing Sorenson 3 Quicktimes
on Feb 2, 2006 at 7:45:23 pm

Here's the short of it:
I've got some Sorenson 3 Quicktime movies that are fairly large in file size. I need to reduce the file size from these existing quicktimes, and not go back to the original material. Any thoughts, experience, or advice for doing this? I'm using Cleaner 6 and 6.5.

Now the long version:
There are over 30 movies, ranging from :30 to 4 Minutes. 720x486 video, 15FPS. The data rate is about 1.35 Mbits per sec. They were all on a variety of CDs, but now need to be incorporated into a single CD. All the movies in combination with what else is on the CD will overload it, and I can't move to DVD-rom. I'm not looking to cut the quality down to web looking, but I need at least a 30% savings in size.
These were completed over several years, and although I could restore the originals (or digitize in the masters), it's a huge hassle and time commitment that the client isn't paying for. That's why I'd like to re-process the quicktimes in a big batch in cleaner 6 or 6.5.
I've never re-comopressed a quicktime before. Do I even need two pass? I don't need de-interlacing right? Should audio just pass through?

Thanks for the help.


Praise to the COW

BrAd Steiner
ImageWorks Media Group

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Dean Steinmann
Re: Re-Compressing Sorenson 3 Quicktimes
on Feb 7, 2006 at 3:13:24 am

This is relatively easy to accomplish. Try one before you do them all. Once you have the settings where you want them, do the batch.

Having not seen the files, I'm not sure if they need to be deinterlaced or not. My guess is that this was already done in the initial compression, so don't bother doing it again

If you want to reduce the files sizes by 30%, reduce the audio and video data rates each by 30%. To retain some of the vibrancy of the image, make sure that you play with the gamma, contrast and saturation in the "adjust" tab.

I would use two pass vbr as well.

Just do a short, 10 second (set in and out point in the "Begin/End" tab) sample using different settings until you are satisfied that the image quality to data rate ratio is where you want it. Once you have reached a satisfactory level, do the batch.

A question you may want to ask is if you really need to have these at 720 by 486. Reducing the dimensions by 20% will go a long way in masking the reduction in quality of this second compression. If the files are are being delivered on a CD, perhaps they can be imbedded in a screen at 480 by 360 with supporting text and graphics around it. The client may like the "new improved" look, and will pay for the upgrade as well.

Another question is why Quicktime? If you compress this in Flash (flv using Squeeze or Compression Master) your viewership will have a much higher rate of playback due to the fact that the Flash 7 plugin required for playback is on 95% of computers. This will mean that part of the interface will have to be developed in Flash as well.

Some examples:

Hope this helps.


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