• Adobe After Effects

  Odd compression behaviour…

  Posted by Mark_c on August 31, 2005 at 9:41 am

  Hello, I have been given a file which is 265Mb. The file is 1024×768, Thousands of colours, and Video compression (according to Quicktime player).

  I have then imported this into After Effects, reduced it’s size to 800×600, and then recompressed using Video compression and the final file size comes out at 447mb.

  How can this be? I would have expected the file size to be about 0.6 of the original size!

  Mark

  Steve Roberts replied 20 years, 8 months ago 3 Members · 3 Replies
• 3 Replies

• 

  Spaceman

  August 31, 2005 at 9:46 am

  spaceman wonders if the original was unmatted and the the second premultiplied?
• 

  Mark_c

  August 31, 2005 at 9:54 am

  The movie has no alpha, so I don’t think that matters, or am I missing the point?
• 

  Steve Roberts

  August 31, 2005 at 1:00 pm

  You may be recompressing at a higher data rate than the original, making a bigger file as a result.

  Try reducing the quality of the compression in the Options dialog, and inputting a number into the keyframes box. Try 15, 30 maybe. It’s a bit of an art.

  Steve

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