[mythtv-users] Some questions about HDTV recording

[Steve Malenfant]

Being frustrated about the whole Display of HD in Linux and MythTV.  I
went and bought the Nvidia DVD Decoder.  I have an ATI Radeon 9700
with a P4 2.4Ghz, playback with the Nvidia DVD Decoder is smooth. 
Only about 33% CPU Utilization using Windows Media Player and the
decoder.

When I use the same with VLC, I"m getting some choppy video and 100% CPU usage.

The only problem I got so far with it is that I can't rewind/forward
using Transport Stream.  When I convert the TS to PS using mpeg2vcr, I
can rewind and playback.

I spent so much time on my linux box trying to figure everything out
of MythTV... I have it working fine with a PVR-250, but it's difficult
using the HD3000.

Xine-hd just doesn't work for me, mplayer does, but can't get 4:3
resolution to use full screen.  MythTv just crash and can't play the
video.

Getting a ATSC STB would seems to make sense, but there is no PVR in
these boxes!  MythTv gets more expensive at the end of the line.  But
I just love MythTV...  I'm not good enough to make it work, not good
enough to fix it.  My wife just hates MythTV because I'm passing all
my free time on trying to make it work, at the end it didn't...

So now I'm recording with MythTV and watching my shows using Windows
Media Player...  It's sad, but once HDTV will be available and
integrated in Windows, it's going to be a lot easier for people to use
it.  Not sure if I'll sell my pcHDTV card on ebay or not soon... 
There is a bunch of new USB 2.0 QAM/ATSC that came out and will come
out soon, it think that's where I'll end up.

Hopefully I informed some people and didn't frustrate any others, but
that's my expiriences...

Steve

On Sat, 11 Dec 2004 23:38:24 -0800, Brad Templeton
<brad+myth at templetons.com> wrote:
> On Sat, Dec 11, 2004 at 11:51:11PM -0600, Nate Carlson wrote:
> > So basically write a shell wrapper that gets called for transcode, and
> > looks at the channel number or something?
> 
> Well, I would actually look at the resolution of the stream if you can
> extract that.  You want to transcode a 480i differently from a 720p or
> a 1080i.  Since most HDTVs are really only 1280x720, that sort of resolution
> reduction from 1080i makes a lot of sense as the TV is going to do it
> anyway.
> >
> > >Tons of them.  HD is new to MythTV.  AC-3 audio also creates problems in
> > >myth and its sound drivers.
> >
> > Well, doesn't sound too horrible, at least.  :)
> 
> I'm finding it to be a pain.  Here are some pains I have seen:
> 
> a) Getting your video card to display on the HDTV can be a lot of work,
> requires pushing the edge, newer drivers etc.   Often this leads to
> hard crashing and upgrade troubles.
> 
>    a2) Many HDTVs won't actually take input at 720p.
>    a3) DVI can be harder to get going than other output forms.
> 
> b) Many xv drivers won't actually drive at 1920 wide.  Some even say they
> do but can't.
> 
> c) Most HDTVs have overscan problems when computer driven
> 
> d) DVD playing needs to be modified to understand 16:9 TVs
> 
> e) The drivers for the HDTV cards can be a pain to work with, and
> they can crash your machine.
> 
> f) Myth TV front end crashes when it tries to tune a channel with a
> poor signal.
> 
> g) Myth TV back end gives up recording a show if there is bad signal,
> and doesn't retry if the signal gets better, and thinks it recorded the
> show so refuses to record a later timeslot.
> 
> h) When you record 1080i, you can get a lot of interlacing artifacts if
> you don't get your redisplay just right
> 
> i) As noted, problems with transcode, recording of non-HD shows using disk
> 
> j) AC-3 sound is not handled well.  The center channel will be missing
> sometimes.  Alsa drivers have bugs, and can cause jittery audio or
> hanging.
> 
> k) I haven't looked to hard, but it's not so clear how to use the
> non-ATSC features of the PC-HD3000.
> 
> l) Did I mention it can be a bitch to get your card to drive your HDTV
> at 1920 x 1080?   Many people give up and drive at 1920 x 540p (but then
> you get interlace artifacts if not careful.)
> 
> m) Sometimes the NVIDIA drivers will flake out doing xv, and it goes
> all blue, and you have to take the module out of the kernel and back in,
> or reboot.  But NVDIDIA are still the best at it.
> 
> n) HD takes a lot of CPU to play, and if anything else pops up on your
> machine, it can cause troubles.
> 
> o) xvmc seems like a win for HD, but reports are it causes a lot of
> problems, and crashes in certain circumstances.
> 
> p) Getting stuff OTA with an antenna is a real pain, we have forgotten why
> we took the antennas down to get cable.  And a rotor (the old solution to
> stations in all directions) doesn't work for a PVR, unless you had a rotor
> aware PVR!
> 
> q) I see some strange display bugs in how the borders are drawn in the
> program menus at 1920 x 1080 res.  The box around the list of programs
> sometimes looks like it's coming from bad memory.  But this is cosmetic.
> 
> r) Some featurs of myth just arnen't ready to be on an HD display, like
> the web browswer and news, the text is too small.
> 
> s) Channel changing is intolerably slow in live viewing (you pretty much
> want to swtich to the guide browse mode for channel change.)
> 
> And I have heard more.
> 
> 
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