[mythtv-users] Video transcoding and scaling quality

[Chris Birkinshaw]

I am trying to transcode a HD recording at 1080i to 720i, and also to SD.

When I run mplayer on the original recording I see this:

Movie-Aspect is 1.82:1 - prescaling to correct movie aspect.
VO: [xv] 1440x1080 => 1964x1080 Planar YV12

So I transcoded to 960x720. Now mplayer does this:

Movie-Aspect is 1.82:1 - prescaling to correct movie aspect.
VO: [xv] 960x720 => 1310x720 Planar YV12


It seems to me that I am losing quality here when mplayer stretches the
image to restore aspect ratio on my 720p file - as I already threw away a
load of pixels in the downconversion. I would also imagine that X has to
scale it again as my screen is 1280x720 pixels. Am I right here?

Is it possible to stretch the 1080 file to the right aspect then scale it
down to a 1280x720 file which would need no scaling to playback? Am I right
in thinking this would improve things?

Thanks,

Chris
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