[mythtv-users] A paradigm shift is coming. Are you ready?

Yeechang Lee ylee at pobox.com
Tue Feb 12 10:14:15 UTC 2008

For the past several years the benchmark for North American high
definition (1080i MPEG-2 content recorded via FireWire or OTA at
7.5-8GB/hour)-capable MythTV frontend has been a Pentium 4 2.8-3.0GHz
with an Nvidia 5200. Anything slower is asking for trouble.[1]
Anything that meets this level of performance or better is in fine

This is about to change, thanks to two imminent developments:

* The pending release of 0.21. The creation of an 0.21-fixes branch in
  SVN is the latest sign that a final 0.21 is coming very, very soon.
* The forthcoming Hauppauge capture device that encodes 1080p video
  and S/PDIF audio to h.264.

Let me use my frontend, a Pentium 4 Hypertransport-enabled 3.0GHz with
an Nvidia 6200TC, to illustrate. 0.21 brings both a new, OpenGL-based
video renderer and two new deinterlacers, Greedy and Yadif. My
frontend is incapable of using the OpenGL renderer at all due to
insufficient horsepower. Even with the Xv renderer, the Yadif (2X),
Yadif, and Greedy (2X) deinterlacers are too much for my frontend;
only Greedy works. Xv and the Bob (2X) deinterlacer still work
wonderfully well in turning 1080i content into output for my 1080p
panel, of course.

The Hauppauge device is another story. I've been playing the 1080p
h.264 videos at <URL:http://www.apple.com/quicktime/guide/hd/> in the
MythVideo internal player and the results aren't encouraging. Besides
the lack of audio (Anyone know why?), most of the videos play with a
brief pause every few seconds and accompaning "NVP: Waiting for
prebuffer" messages in the mythfrontend log. Seeking is
problematic. Some, like the Ducati and Barber of Seville clips, don't
play at all. mplayer can play all the clips, properly handles the
audio, and seeks better, but of course doesn't try to deinterlace by
default; using -vf yadif=1 results in a flickering display and frame

I don't know if I need more CPU horsepower or GPU horsepower;
<URL:http://www.mythtv.org/wiki/index.php/HD_Playback_Reports> implies
CPU is more important, but a faster video card would surely help. As
noted above Xv and Bob are quite satisfactory and I don't need the
Hauppauge device, per se, because all my HD channels are available via
FireWire. I strongly suspect, however, that many of those who are
going to be jumping to 0.21 and the Hauppauge device in the coming
weeks and months are going to be mightily disappointed without
upgrading their previously-satisfactory setups first.

[1] Anyone who here jumps up and says "I can use a way slower system
with XvMC!" or "I can play 1080i with my MX440!" is both missing the
point and misunderstanding the meaning of "benchmark."

Yeechang Lee <ylee at pobox.com> | San Francisco CA US

More information about the mythtv-users mailing list