Hello friends...

I just (at last :)) made an animation with my Vue 5 Infinite. Rendered it as 640*480, 24fps Quicktime format but file size is too high (99.712kb). Is there a method to reduce file size without reducing quality ?

thanks in advance

Kerem

Yes and No (with a heavy emphasis on No ;-) ). Size is a factor of resolution and bitrate and bitrate is directly related to quality. Smaller filesize means either smaller resolution at the same bitrate/quality or the same resolution and lower bitrate/quality.

The question is at what point is the quality loss perceptible in your animation? For example: your average DVD is encoded in MPEG2 with a bitrate of 6000-8000kbps. I have encoded DVD’s at 4000kbps to fit more on a disc and the quality loss is imperceptible. Going lower than 4000kbps starts to show compression artifacts that are unpleasant to my eyes.

The other question is, what is your target audience? If it’s the web then what is acceptable quality for you on the web? This is also based on content. A lot of movement and changes in scenery needs more bits to encode than a talking head on a solid background. Finally, you can use a variable bitrate (VBR) and a 2 pass encoder which will give more bits to the scenes that need it stealing bits from the scenes that don’t and all the time keeping the filesize acceptable. Also some codecs (encoder/decoders) are more efficient than others. Quicktime is just a container. It can use many different types of codecs.

I would start by lowering the bitrate and rendering a sample to see what you think. Render just 1 second and then multiply the filesize by however many seconds are in your animation until you get an acceptable filesize. If the quality is unacceptable at that point, then consider lowering the resolution from 640x480 to 320x240. Like anything else you have to weigh the trade-offs. If you have multiple codecs available to you, try a couple of them and see which compress better with higher quality.

~jr