[mythtv-users] Best hardware to build dual tuner? (HD(QAM) + Analogue, but run out of slots)
kminney at telus.net
Wed Feb 21 03:22:40 UTC 2007
Thanks for your help. It looks like the Plextor units only do standard
definition but the HVR-950 looks really interesting, shame that there are
problems with it running in MythTV though. I could easily hide two of these
HVR-950's inside my Myth box and the cost of each looks quite reasonable.
Also, I have heard back from Jack Kelliher of pcHDTV, and this is what he
had to say about the HD5500 and getting the audio when capturing analogue
" The easiest way is to use an audio cable connected to your sound
card but the HD-5500 also uses the cx88-audio driver that can dma the audio
across the pci bus to applications that can used it. I do not know
for sure if mythtv supports both audio device types so you should check the
mythtv forum also.
For testing we use tvtime to select a channel followed by arecord -D
hw:1,0 -r 48000 -c 2 -f S16_LE | aplay -
Which grabs the digital from the HD-5500 card and plays it back.
When using the audio cable the sound card digitizes the audio and it
is passed to an application such as mythtv which then encodes it in the mpeg
stream for recording. With the cx88-audio driver the HD-5500 card digitizes
the audio and then this driver passes it to an application such as mythtv
which would then encode it."
So, it seems that I don't need to use the audio cable (don't have two inputs
to my sound card anyway!) but should be able to get audio over the Pci for
my analogue NTSC.
I need to check if this actually works in MythTV in practice though, and if
there are any issues. I installed MythTV using KnoppMyth R5E50 so I have
MythTV 0.20 installed. I don't know when KnoppMyth is likely to be updated
to incorporate MythTV 0.21 and haven't a clue how to do this manually. If to
get this working I find that I need 0.21 then I may need help to do this.
I also heard from someone who has the DVICO Fusion HDTV Lite who tells me
that it has analog capabilities as well as ATSC, but the analog signal is
Does anyone know what the NTSC analogue audio and video is like from the
From: Patrick Wagstrom [mailto:patrick at wagstrom.net]
Sent: Tuesday, February 20, 2007 1:34 PM
To: mythtv-users at mythtv.org; kminney at telus.net
Subject: re: Best hardware to build dual tuner? (HD(QAM) + Analogue, but run
out of slots)
> This is my first post to this forum, so hopefully it makes sense and there
> someone out there that can help me.
> I have a MythTV system which I have been building for a few months now. I
> started out by buying two Airstar HD5000 PCI capture cards. This worked
> for HD which I could receive using clear QAM, however I was only able to
> four SD channels. Subsequently I discovered that these are on free trial
> are unencrypted. The rest of the SD channels are transmitted as encrypted
> digital or analogue NTSC (unencrypted).
> My aim was to build a dual tuner HD+NTSC(analogue from cable) system but
> have a problem as my Airstar cards take up one PCI slot each and I only
> two PCI slots on my Asus M2NPV-VM motherboard. I have no slots left to add
> analogue capture card.
> I am trying to find a solution which will allow me to capture
> using all combinations of the two tuners, i.e. SD+SD, SD+HD, HD+HD
> The only options I can see are to add a HD Homerun for the HD and have a
> of analogue capture cards in the PCi slots, but then I end up having four
> connectors to hang on my cable and also my Airstar cards would be
Have you considered using an external USB or Firewire device to do some
of the capturing? Plextor makes a line of external tuners that work
well with MythTV. Some of Hauppauge USB stuff also works, the HVR-950
provide ATSC and analog support however I don't think that analog is
working with MythTV right now.
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