[mythtv] keyframedist discrepancy

Isaac Richards ijr at po.cwru.edu
Sun Jun 1 21:15:38 EDT 2003


On Sunday 01 June 2003 05:16 pm, Craig Longman wrote:
> i've been trying to figure out why the total time on my transcoded
> recordings (converted to mpeg-4)  is always wrong, they show up as half
> as long as they actually are.  the problem seems to be that the
> NuppleVideoRecorder assumes and sets keyframedist to 30, but
> AVFormatDecoder assumes a keyframedist of 15.
>
> which one is correct for mpeg-4 video?  the mpeg-2 stuff is 15, but that
> might just be because it doesn't handle larger gops, but i do notice a
> definite little jump in the smoother areas of the image when i use a
> size of 30.

30's what the software encodes use...  I don't see how it could be an issue, 
though, as you're re-encoding the video, so it should be making its own (new) 
keyframes in the NVR class...  Unless, are you doing anything with the 
seektable?

Isaac


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