[mythtv-users] Playback of HDTV, HDHomeRun

Dan Ritter dsr-myth at tao.merseine.nu
Thu Jul 17 10:17:21 UTC 2008


On Wed, Jul 16, 2008 at 09:36:58PM -0700, David Smiley wrote:
> 
> I have a P4 at 2.8 GHz and I've been using it just fine with a Hauppage 250
> card for nearly a year.  I just purchased a flat screen TV and an HDHomerun. 
> I got the HDHomerun to record a snipped of a high-def program for just 11
> minutes (which was 1.26 GB !).  The playback is basically impossible; choppy
> doesn't begin to describe it.  I suspect it's some sort of super high-res
> MPEG2 format but I don't know how to get at info on my video files so I am
> not certain.  An auto-transcode of this file brought it down to only 1.1 GB
> but that didn't help the playback (unsurprisingly).  In my playback
> settings, I observed that there are various filters 'n such that apply
> depending on the resolution.  I did some tinkering there on the higher
> resolution stuff but haven't gotten success.  Can someone advise me on
> things to try and/or how to go about troubleshooting playback of HDTV?

That's a normal data rate for HDTV. It's MPEG2 with (probably)
AC3 sound.

Good news: XVMC works on MPEG2 of any size. Set that up if you have an
NVidia 5xxx-7xxx card, or an Intel graphics adapter.

More good news: transcoding downwards will probably still look
pretty good. I like:

mencoder -vf scale=640:480 -ovc lavc -lavcopts \
vcodec=mpeg4:vbitrate=2100000:keyint=25 -oac lavc -ni -forceidx

which gives about 1 GB/hour final size, and fairly smooth
FFW/REW.

-dsr-



-- 
http://tao.merseine.nu/~dsr/eula.html is hereby incorporated by reference.

When freedom gets lots of exercise, it protects itself.


More information about the mythtv-users mailing list