[mythtv-users] External Channel Change Script for DVB cards

[Raymond Wagner]

On 10/30/2011 08:11, Colin Albert wrote:
> On 10/29/2011 11:29 AM, Devin Heitmueller wrote:
>> On Sat, Oct 29, 2011 at 10:39 AM, Colin Albert<colintrebla at gmail.com>  wrote:
>>> I am reviving and old thread.  It relates to an issue that is a problem for
>>> me and will be an ever increasing problem as Cable companies continue to
>>> adopt SDV.
>>>
>>> The problem: I have a QAM card and want to build a MythTV box instead of
>>> using the cable company's (busted/worthless) DVR. The cable company uses
>>> SDV, so QAM is limited to OTA locals.
>>>
>>> My solution: get a set top box from the cable company, hook it to my
>>> MythTV.  Use a External channel change script to change channels so that the
>>> box is requesting the channel that I want. Then change the channel on the
>>> QAM card to that channel.
>> This won't work.  The RF output on the set top box is NTSC (analog
>> only).  You won't be able to tune to it with a QAM tuner.  You would
>> have to use an analog tuner set to channel 3.
> But if I spit the input to the cable box then let the cable box and the
> QAM card tune the same channel.  I am only using the cable box to
> request the cable co to send that channel to my house.  Once it is being
> broadcast I can receive it normally on the QAM card.

You would have absolutely no idea where it is sending that channel to, 
so you would have no way to tune it with the QAM tuner.  Even if you did 
have a couple minutes to perform a channel scan, there would be no 
identifying information to denote it as such.  Even should someone write 
proper USB tuning adapter support for Linux, my bet is that the updated 
tuning data would come through an OOB event, rather than over the USB 
connection.