[mythtv-users] Playback of HDTV, HDHomeRun

[David Smiley]

This is probably a newbie question but where exactly in mythtv do I tell it to "transcode" (if that is the right term here) the file using the mencoder options you gave?  I did look already but I'm confused.  Whenever I see references to mythtranscode, it seems to be in the context of exporting out of mythtv which I don't want to do.  Maybe I'm supposed to set up a special "job" for this; I'm not sure.

~ David

> 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-