Compressor settings for HD to SD

[Paul Colin]

Thanks Michael, that’s a big help.

[Paul Colin]

Thanks Brad, I’ll try with this configuration

[Rafael Amador]

Hi Paul,
The more “I” frames (original) you set, the better your movie will look but you will need to rise the data rate accordingly to sustain more “I” frames. Think that with a “IP” structure you have one “I” every two frames, instead of one every 15 with the standard GOP.
What I recommend you is to use Open GOPs. BitVice and CinemaCraft set them by default. And never
use CBR.

[Brad Elliott] “MPG files for DVD need to be closed. Stand alone MPGs(muxed with sound) should be open. “
This is not correct. I master the DVDs with Short/Open GOPs and works perfect.

Best,
rafael

http://www.nagavideo.com

[Brad Elliott]

Rafael,

All of Compressor’s presets are closed GOP.

I have read that closed GOPs are recommended for DVDSP and that closed GOPs are required for multi-angle DVDs.

Am I mistaken?

My opinion on short GOPs is based on our hardware encoding card’s presets. 90 minutes or longer use shorter GOPs while 60 minutes or less have 15 frame GOPs.

What advantages have you found in using shorter GOPs?

Brad

[Rafael Amador]

Hi Brad,
You need to duplicate the preset and set “Video Format” to NTSC or PAL. Don’t let it in Auto. Then you will be able to tweak the GOPs.

[Brad Elliott] “My opinion on short GOPs is based on our hardware encoding card’s presets. 90 minutes or longer use shorter GOPs while 60 minutes or less have 15 frame GOPs. “
Right. Long GOPs means less “I” frames. You can low the data rate so you can put longer movies in a DVD.
Short GOPs means more “I” frames. There are more original pictures that are used as refference for compression and de-compression. You can achieve more quality.

I told you, is interesting to use Open GOPs. Closed GOPs have one “I” frame that is the “reference ” frame.
With Open GOPs, each GOP use his “I”frame, but also uses the GOP before as reference.

[Brad Elliott] “I have read that closed GOPs are recommended for DVDSP and that closed GOPs are required for multi-angle DVDs. Am I mistaken?”
DVDSTP doesn’t care much about the GOPs. Only in the case of Multi-angle DVDs there is the limitation that you points. As I told you, by default BitVice and CinemaCraft works with Open GOPs.
Are you making a multi-angle DVD?
rafael

http://www.nagavideo.com