• VEGAS Pro

  understanding file size diff

  Posted by Gilles Gagnon on April 8, 2011 at 8:15 pm

  I have a 3 minute Quick time .mov file of very good quality (SD) and it’s 770MB in size.

  I bring that in, add some music, a few sound effects and render it as mpg2/ntsc dvd. the output size is 160MB.

  why such a huge diff? Am i choosing the correct rendering to get the best quality?

  Cheers,

  Gilles

  Gilles Gagnon replied 15 years, 5 months ago 2 Members · 2 Replies
• 2 Replies

• 

  John Rofrano

  April 9, 2011 at 3:12 am

  [Gilles Gagnon] “Am i choosing the correct rendering to get the best quality?”

  That’s hard to tell since you didn’t tell us what codec and bit rate you used for the source file. I assume the rendered file was MPEG2 6Mbps. MPEG2 is about 25:1 compression. In contrast the DV source from an SD camera is about 5:1 compression. So it makes sense that the output would be 5x smaller, yet we watch MPEG2 DVD’s all the time and think they are high quality. So going from 770MB to 160MB is not that uncommon and very similar to going from NTSC DV to NTSC DVD MPEG2.

  ~jr

  http://www.johnrofrano.com
  http://www.vasst.com
• 

  Gilles Gagnon

  April 11, 2011 at 3:23 pm

  Thanks for the clarification John. It makes sense.

  Gilles

  Gilles

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