[MPlayer-users] What are b_frames for and should I use them for my mpeg2 encodings(for DVD) ?

[Rich Felker]

On Fri, May 20, 2005 at 08:15:44AM -0400, Giacomo Comes wrote:
> On Fri, May 20, 2005 at 09:56:55AM +0100, VJ wrote:
> > Hi,
> >    As the subjects says, I want to learn what B-frames are, what is
> > their role and will they benefit my mpeg2 encodings which eventually
> > end up on burnt DVD's?
> 
> This is not a technical answer, but what you can expect as an user.
> 
> With B frames your mpeg will usually be:
> smaller
> with a lower PSNR
> take a longer time to encode.

the first and second are totally false without more information.
personally i strongly recommend against using b frames unless you have
a very good reason. they rarely help quality:bitrate ratio, and they
slow down not only encoding but also decoding, among adding lots of
other complexities if you want to remux the video later. however,
strict dvd compliance may require them...

rich