[mythtv-users] Does higher bitrate and resolution benefit HDTV?

osma ahvenlampi oa at iki.fi
Sat Dec 16 11:17:20 UTC 2006

On 12/15/06, Gary Taylor <squeaky at sdf.lonestar.org> wrote:
> I want to use Myth to archive my analog 8 mm camcorder home movies to DVD.
> Right now I only have a 20 year old TV, but eventually I imagine it's
> inevitable that I'll get an HDTV.  Will saving my home movies using the higher
> resolution and bitrate that the HQ profile in Archive Files provides, provide
> me any advantage when viewed on HDTV when I get one?

According to http://www.high-techproductions.com/choosing.htm, a 8mm
camcorder has a resolution of 270 lines, so capturing more than that
will not benefit you. Generally speaking, you should use about the
same amount of horizontal resolution as you have vertical (in dpi,
taking into account the 4:3 aspect), so a capture of 352x288 (or
quad-PAL resolution) should be about the right capture/archive res for
those tapes.

As for bitrate, MPEG-4 ASP is designed to work well with 0.25 bits per
pixel. The above resolution looks "good" at 600-700 kbps, and I'd
consider it archive-quality at 1200 kbps. MPEG-2 would require
bitrates of about double that.

However, it'll never look good on a HDTV without extensive
postprocessing, due to the source format's lack of resolution. In
fact, the end result won't be significantly different from the typical
iPod video of 320x240, 500kbps, but the higher bitrate will make it
better with motion than a "YouTube quality" clip at 320x240, 200kbps.

Osma Ahvenlampi   <oa at iki.fi>       http://www.fishpool.org

More information about the mythtv-users mailing list