[mythtv] I had to hack sa3250ch.c to get it to work

Scott Alfter mythtv at salfter.dyndns.org
Sat Jul 22 04:19:06 UTC 2006

A post over on the main MythTV list motivated me to try setting up channel 
changing over FireWire instead of over infrared.  I found sa3250ch.c in the 
MythTV 0.19 tarball and compiled it.  At first, it complained that it didn't 
find a cable box to control, but that was fixed by changing the vendor ID from 
0x000011e6 to 0x00000a73.

Once that was fixed, it saw the box, but it was changing to the wrong channel. 
  After some experimentation, it seems that much simpler code works with my 
cable box.  The original code breaks up the channel number into three ASCII 
characters, shifts some of them by varying amounts, and ORs them together with 
a constant.  Channel 256, for instance, results in cmd[1] getting set to 
0x04323536.  I found that just taking the channel number, shifting it left 8 
bits, and ORing it with the constant produced the correct result,  In this 
case, channel 256 results in cmd[1] getting set to 0x04010000.  cmd[0] and 
cmd[2] remain unchanged.

If it matters (and I suspect it does), my cable service is through Cox in Las 
Vegas.  A patch with the changes I made is attached.

  / v \ Scott Alfter
(IIGS( http://alfter.us/            Top-posting!
  \_^_/ rm -rf /bin/laden            >What's the most annoying thing on Usenet?

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