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

[Bob Sully]

> Message: 26
> Date: Tue, 12 Feb 2008 02:14:15 -0800
> From: Yeechang Lee <ylee at pobox.com>
> Subject: [mythtv-users] A paradigm shift is coming. Are you ready?
> To: MythTV user mailing list <mythtv-users at mythtv.org>
> Message-ID: <18353.29047.840033.605474 at dobie.ylee.org>
> Content-Type: text/plain; charset=us-ascii
>
> 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
> shape.
>
> 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
> drops.
>
> 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


I know that this is (by the standards of THIS list!) an "old" thread.  But
I finally got a chance to try this out, because I am going to grab one of
those Hauppage devices as soon as they're available.  I run Myth on this
setup:

Asus K8N-E Deluxe motherboard
Athlon-64 Turion "4000+" 2.4GHz overclocked to 2.6
2G DDR 400 RAM
NVidia generic 6200 AGP 8X video card (with AGP overclocked by about 7%)
Lots of SATA HD space (1.2TB LVM group for Myth recordings, 700G for
everything else)
Mandriva 2007.1 64-bit with Myth 0.20.2 RPMs (approx. SVN 14440)
SilverStone LC-14M case

The TV is a Samsung 61" DLP (1080i); I run the GUI in 720p, because using
it as a computer in 1080i (with terminal windows) is fugly.

I downloaded a bunch of those H.264 videos from the Apple site that
Yeechang mentioned, and tried playing them using mplayer within Myth.  I
figured that, based on the above, the results would be awful, using this
single-core CPU...I had been looking at Newegg.com earlier, assuming I'd
need new hardware.

I used this setting to play these:
mplayer -fs -quiet -ao alsa:device=spdif -channels 6 %s

I almost fell out of my chair, because they all played beautifully.  Of
course, the 1080p ones were "scaled" to 720p.  Using top, it reported CPU
usage at about 90% with the 1080p vids and about 60% with the 720p
versions.  With the 1080p ones, there was the slightest bit of frame
skippage at the very beginning of the vid, then that went away; there was
none on the 720p ones.

I also tried it without the -fs option, so on the 1080p vids, I was
missing part of the frame (the right and bottom third), but they still
played very nicely.

So, perhaps there is hope yet, for those of us with slightly older
hardware.  This motherboard is perfect for Myth, as it has 5 PCI slots,
plenty of SATA interfaces, SPDIF, etc.; the processor is a low-power unit,
which saves on electricity - so I'd really like to hold onto it for as
long as I can!

Bob

-- 
________________________________________
Bob Sully - Simi Valley, California, USA
http://www.malibyte.net
http://www.malibyte.com