[mythtv] NuppelVideo format, keyframes, and the cutlist

Isaac Richards ijr at po.cwru.edu
Wed Jun 18 12:02:25 EDT 2003


On Wednesday 18 June 2003 09:04 am, Geoffrey Hausheer wrote:
> On Wed, 18 Jun 2003 02:19:04 -0400, "Isaac Richards ijr-at-po.cwru.edu
>
> |mythtv/1.0-Allow|" <e6kbhbk35r0t at sneakemail.com> said:
> |
> > Hmm.. though.. Had you thought of a new frametype that just says 'skip
> > the
> > next X frames'?  That way you should be able to just cut on key-frame
> > boundaries, and then just skip up to the real end of the cut
> > automatically
> > during playback..  I dunno, though
>
> Actually this is sometghing to think about.  At one time you (or someone)
> had said that they didn't want to limit commercial-clipping to keyframe
> boundaries.  If we do (at least for 'clipped' files), I do have the
> option of either (a) rounding to the nearest keyframe (which means that
> you could lose up to 1.2 seconds of your show, or (b)
> conservatively-rounding to the next keyframe (which means having to watch
> up to 2.4 seconds of commercials).  I had initially just rejected this
> outright, but there was no good reason to do so.  If I do this, I don't
> think I need a new frametype (I'm going to rewrite the frame-headers
> regardless), and all of this code isn't needed.  It also hugely
> simplifies the reencoding proces, since I don't need to do any encoding
> at all.  Perhaps that is an acceptable tradeoff (trading off user
> experience for file/code complexity)?

Well, if there's something in there that tells it not to play X amount of 
frames (for video _and_ audio), then that's fine.  There'd be a tiny amount 
of extra frames in the video file, and the total length would be slightly 
longer, but the user wouldn't really know that.  There's no real point in 
allowing people to edit out commercials down to the exact frame if it's not 
going to support it =)

Isaac


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