[mythtv-users] Speaking of transocding: 1080i deinterlace?

[Brad Templeton]

Speaking of transcoding HDTV, in particular 1080i recordings,
I wonder if people might share their success stories on this.

I have four possible goals for transcoding 1080i. (720p is pretty
easy to figure out)


a) Keep all 1080 lines, but save disk space
        Presumably:  Turn on interlaced DCT and interlaced motion estimation
        Keep video size the same.
        Set to around 6 megabits/second (to taste)


b) Reduce the resolution to 1280x720, deinterlace,
        Do we put a filter in custom filters like kerndeint?
        Do we leave interlaced DCT and motion estimation off, as the
        filter will come first?

c) Reduce the resolution to 1280x540 or even 1080x540, giving
            up half the lines and of course deinterlacing.

        Do we use a different filter than above?  Perhaps "onefield"
        is simpler or is it better to stick with kerndeint or
        linearblend?

d) Reduce SDTV video that was upconverted and letterboxed back to SDTV

        1) Reduce to 960x540 to get a perfect deinterlace.
           What is the best filter and flag setting for that?

        2) Reduce to 854x480 to match the true lines in recording.
           What is the best approach?

        3) Reduce to 720x540, cropping off the letterbox bars
            Can the crop filter of mythtranscode do this? The
            docs suggest it adds bars.   This is my ideal choice
            for a perfect deinterlace and quality recording



For 720p recordings, it's all much simpler, no deinterlace issues,
though for upconverted SDTV it would be nice to crop but since I
presume the mp4 codec wastes little space on the letterbox bars
that it isn't a huge issue.

What success have people had?