Is the video quality dependant on compression % or bitrate

[matthewmalay]

For a transcoder like DVDShrink.

[Gurm]

Yes.

- Gurm

[matthewmalay]

Which one is more important though. I've got a DVD, its like 75 minutes long and the main movie was like 5.5 gigs including audio so the compression % should be around 75%, I've done stuff at that % and the quality was pretty good but could have been better. But for this DVD the bitrate of the transcoded video will be much higher so will the quality be better?

[bugster]

Try it and see.

The size of a DVD (or any mpeg) is dependant on on only 2 things, bitrate (average in case of VBR encodes) and playing time.

So if you have a movie that is only 75 minutes but is 5.5 Gigs it must be a pretty high bitrate. Therefore transcoding it to reduce its size by 25% will reduce its (average) bitrate by 25%. This will still be a higher bitrate than say a 2 hour movie at the same filesize. Will it be better quality, who knows? It depends on far too many things, especially the kind of material in the movie.

Movies with lots of fast movement, flashing lights etc need a high bitrate to maintain quality. Music videos are notorious for this. Movies with just a talking head or very little motion can be encoded at MUCH lower bitrates and still look great.

But when it comes to quality, only your own eyes can be the judge

[FOO]

Neither one is more important. For a given length movie
the bitrate and compression ratio are proportional.