[mythtv] Interlaced vs. Progressive
ijr at case.edu
Mon Feb 27 16:04:33 UTC 2006
On Monday 27 February 2006 10:21, David Asher wrote:
> Ok, I spent some time looking into this yesterday.
> One call to SetVideoParams is in InitVideoCodec. It looks like this
> would be a great place to use something other than kScan_Detect, but
> that would require decoding some video frames during init. I started
> thinking about that and realized that there is no reason why the
> interlaced status of a video stream need be the same all the way
> through. For instance can't an ATSC transmission switch to 480i for a
> little while and then back to 720p? I don't think practically it
> happens with any of my stations, but I think it could. Also certain
> DVDs are known do this, aren't they?
> So, it occurred to me that it would be better for the interlacer to be
> turned on and off in GetFrame based on the current avcodec_decode_video
> results. Do this seem reasonable? It looks like it would require some
> changes to how NuppelVideoPlayer handles the deinterlacer. I wanted to
> check before trying to implement it to make sure I'm not running down
> the wrong path.
Yup, this would be better. The only tricky bit is deciding to double the
framerate or not if bob is being used.
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