sorry guys one more.....what are the benefits to importing HDV as Apple's Intermediate Codec? I know the file size is much larger but I was wondering how this affects the video?
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HDV with Apple's Intermediate Codec?
- Thread starter Hans86
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HDV uses interframe compression (it's MPEG-2 video) whereas AIC uses intraframe compression like DV.
With MPEG-2, frames are compressed together into GOPs (groups of pictures). This allows motion to be compressed - for example, in a shot with a ball moving across a static background, the background will get compressed and only the ball has to be updated each frame. The result is much better compression but also much greater difficulty in editing since each frame depends on what comes before and after it - if you edit one frame it affects its neighbors etc.
With AIC, each frame is compressed one-by-one and independent of any other. This makes for much easier editing at the expense of lower compression ratios and larger file sizes. The goal of AIC is to make HDV easy to edit while affecting picture quality as minimally as possible.
With MPEG-2, frames are compressed together into GOPs (groups of pictures). This allows motion to be compressed - for example, in a shot with a ball moving across a static background, the background will get compressed and only the ball has to be updated each frame. The result is much better compression but also much greater difficulty in editing since each frame depends on what comes before and after it - if you edit one frame it affects its neighbors etc.
With AIC, each frame is compressed one-by-one and independent of any other. This makes for much easier editing at the expense of lower compression ratios and larger file sizes. The goal of AIC is to make HDV easy to edit while affecting picture quality as minimally as possible.
I've been editing with HDV for some time now but have never really encountered any problems with it. I experimented with AIC for a while but it just seemed like a waste of disk space.
Are there any specific situations where AIC would be particularly beneficial?
Are there any specific situations where AIC would be particularly beneficial?
Well, it depends a lot on the edits/manipulations used in a given project. AIC (and the newer ProRes 422) cannot add quality to the HDV-recorded image that isn't there to begin with - but they can reduce the quality loss that results from the application of filters and edits. That's why with FCS2, many like to still capture in HDV but render to ProRes 422 - seems to be the best of both worlds (i.e. low storage for captured files, improved quality for rendered effects/edits/transitions).
- Martin
- Martin