Compression Question...

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...I am posting this question in the newbie section because when I looked around for an answer I couldn't really find one :no: But I was sure that possibly if I didn't know maybe others didn't know either....

So, here's my question: What is 'compression'? What is its purpose? How does it work and why should I be worried about it?

I have found that the details can really slow you down. For me, this is one of the details. Will Vincent has a post explaining how to do it from a Mac computer, but maybe there is some more we could know....

--spinner :cool:
 
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Raw AVI (DV) is too large to download or stream, so we compress the video down to make the file smaller.

While this does somewhat degrade the quality of video and audio, the tradeoff is mostly acceptable for the ability to download the file quickly or distribute it using the least amount of bandwidth.

I suggest Quicktime. H.264 compression @ 256kbit video, 64kbit AAC audio @ 320x240. The filesize is extremely small while the quality is very high.

Windows XP comes with 'Movie Maker', a free video compressor. I don't like to use this because the Windows format generates small files, but the quality suffers greatly.
 
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When the guy moves around he will be rendered

spinner said:
...thanks, however....

My question: What is 'compression'? What is its purpose? How does it work and why should I be worried about it?

--spinner :cool:
Click to expand...


Compression: Make something bigger, smaller
Purpose: To make things smaller
How does it work: Concerning footage compression, there are many different ways to compress your footage. You can compress for quality, or size. The smaller the size, the less quality and vice-versa. From my understanding, in a general sense, there are keyframes. So every keyframe it will look for a changed pixle, if it's the same it doesn't have to re-render that pixle. For example, if you have a guy in front of a building talking and there's little or no camera movement, the pixles of the building will be checked at each keyframe but not rendered since it's the same pixle. When the guy moves around he will be rendered at each keyframe.

I hope I made that understandible.:no: :huh:

Why worry about it?
You want people to see your film right? Well you can't have a 1: clip size be 54megs and expect us to download it and watch it. It's too big for the length of video. You need to find the happy medium of quality and size that would be acceptible for viewing.:D

I hope I'm not too far off:lol:
 
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Coot!

Thanks for the help. The reason I ask is that I am going to be trying to get my short online and the 5 minute final product was edited on FCP. When I attempted to upload it, I got a message saying it was 1GB....uh, it should be alittle smaller :D . The thing is that I don't know how small it should be or what is normal for an upload. So, I was askin' :D

Will V!

...actually since I have a Mac to do all of my editing, the apple link was a good one. I expect to try to use it this weekend.

mrde50!
I think I was making the answer more complicated than it had to be. thanks for your help as well

if you can think of anything else I should know or could use, keep 'em coming....

-- spinner :cool:
 
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ok, here's the settings I use from final cut:

Export via quicktime export (under file menu). I change the codec to mpeg4 (but h.264 does pretty well) for video and audio under the settings button, and change the size to half in both directions (custom size, 320x240 in most cases in the US and Japan - NTSC). This tends to get pretty good sizes, play with them and see what suits you.
 
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...okay, I'm going to quicktime conversion, options,settings, to MPEG-4 Video.

Its gets to 79% and it stops. So, I restarted it, did the steps over, 79% and its been there for about 15 minutes.

Anyone know what may be the trouble?

-- spinner :cool:

By The Way, this is only one of the suggestions I am attempting. If there are particular settings that you might suggest, suggest away....
 
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