[mythtv-users] bitrate questions

[Chris Petersen]

> You use 2G+ per 40 minutes?  wow...  but that doesn't exactly correlate to 
> your 2800Kbps setting, does it?

Guess I had that wrong.  It's 1.8G per 1 hour and 6 minutes (pre/post 
extra)..    The 1.5G 36-minute shows were actually encoded at 3000kbps.

> I don't know what 3:2 pulldown is.  Is that the same or similar to two-pass 
> encoding ?  Is this what prevents realtime encoding to make these smaller 
> files ? 

3:2 pulldown (somehow related to, if not the same as, inverse telecine) 
is a way to trim out frames (thus losing quality by having a lower 
framerate) to make bandwidth room for better-quality frames.  So you end 
up with a lower framerate, but higher quality frames.  The "pulldown" is 
then reversed on playback so that it *appears* to be full framerate.  It 
makes a huge difference when encoding svcd (since you usually just toss 
out the interlaced frames, too) if you don't mind losing a little framerate.

-Chris