[MPlayer-users] mpeg2video for DVD authoring?

Erik Slagter erik at oldconomy.com
Mon Sep 8 13:10:06 CEST 2003

> Okay, I haven't gotten around to testing a new stream yet, but I managed
> to find out the real DVD keyframe requirements.  First I was searching
> using the word keyframe, which didn't work.. then I searched using
> i-frame, which didn't work. Finally I realized that what I wanted was
> to search for "GOP length". It's not that DVDs require a certain rate
> of i-frames, oh no, its just that there's one I frame per GOP, and 
> there IS a maximum GOP length. grr... Anyway, it turns out this
> length is 18 for MPEG1 NTSC, 15 for MPEG1 PAL, 36 for MPEG2 NTSC, and 
> 30 for MPEG2 PAL.  If I'm lucky, mplex creates the GOP's accordingly.

I am afraid mplex can't help you out here. It's the encoder that
determines the gop size.

What a strange gop sizes? 30 for MPEG2 PAL means 1 second + 5 frames...

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