[mythtv-users] Using CableCard tuners other than the HDHR Prime or Ceton

[Ronald Frazier]

On Tue, Dec 6, 2011 at 11:26 AM, Ray Parrish <rparrish at gmail.com> wrote:
> I was recently given an ATI DCT (digital cable tuner) which connects
> via USB and was one of the first CableCard tuners brought to market.
> In the Windows environment, it communicates with the host PC through
> UPnP calls over a network interface similar to what I have read about
> the Ceton tuner.
>
> I wanted to see what the process is for determining what would be
> needed to make it work with MythTV. I believe it will behave similarly
> to the Ceton or the usb-based CC tuner released by Hauppauge. It also
> only has one tuner.
>
> When I connect the device to my backend, it creates a network
> interface eth1 with an IP address of 192.168.119.90. I was able to
> determine that the IP of the tuner is 192.168.119.89, and I can bring
> up its web page.
>
> I am currently running 0.24-fixes from Mythbuntu autobuild repos. In
> theory, should it simply work if I add it as an HDHR by IP address?
> Hopefully Ron Frazier can shed some light on this topic from his work
> on getting the Ceton tuner working.

There are 2 basic parts to using the tuner...control (ie: tuning,
retrieving status, etc) and streaming. The HDHR recorder uses the
proprietary libraries for control, and streaming is just done via raw
data streamed to a socket. My Ceton recorder for 0.24 uses web (HTTP)
requests for control and streaming is just reading raw data from a
device file. My Ceton recorder that got added to trunk recently uses
the same HTTP mechanism for control, but uses RTP/RTSP for streaming.

So what you'd need to do is figure out what mechanisms to use for each
of these tasks. How do you communicate with it to change channels and
get the stats. How do you retrieve the streamed data? Then you need to
write the code to deal with both of those mechanisms.

The industry standard method of doing this for an OCUR device is to
use the DRI, which is a combination of RTP/RTSP for streaming and
UPnP/SSDP for control. When the OCUR recorder is ready this should all
be taken care of automatically, but that's not going to be ready until
0.26. The RTP/RTSP part only exists in my trunk code, though I'm
rewriting my old 0.24 patch to use it too. It was roughly finished up
about a week ago, but I've been sidetracked, so I haven't put it
through the paces, or cleaned it up and packaged it. So if you are
using 0.24, you could maybe use that as a starting point once I get it
released. Then you'd just need to convert all of my Ceton specific
HTTP control code to whatever method you'd use on the ATI (either it's
own proprietary method, assuming there is one, or you can try to
figure out the DRI stuff and code that up).

Of course, this is all assuming you can even get it working in linux
to begin with. I don't recall the details, but it seemed to me there
was something about the ATI that made it problematic to use in Linux,
which is the reason people were so excited when the Ceton & Prime were
announced. It might be that all communication with (or video from) the
ATI is encrypted for Windows DRM. Or maybe there just aren't any linux
driver.

-- 
Ron Frazier