[mythtv-users] Is anybody able to change channels on a 4250HDC STB via firewire?

[Christian Szpilfogel]

Matt Emmott wrote:
>
>
> On Thu, Jun 4, 2009 at 8:36 PM, Christian Szpilfogel 
> <chrisznews4 at rogers.com <mailto:chrisznews4 at rogers.com>> wrote:
>
>     You are going to have to debug this lower down. I haven't seen
>     these vendor IDs on an SA4250 (not necessarily an issue) and the
>     Model ID of 0 is unusual to me as well. Your thread however
>     indicates you compiled those values into the channel changer.
>
>     In an earlier email you found:
>     /sa4250_ch -v
>
>     node 0: vendor_id = 0x00001106 model_id = 0x00000000
>     node 1: vendor_id = 0x000022ce model_id = 0x000010cc
>
>     22ce IS a Scientific Atlanta box and 10cc is a model as well. Have
>     you tried this pair? Your thread suggests you did not.
>
>     I also asked you earlier for an output of plugreport and you did
>     not do this. Can you do this?
>
>     sa4250_ch_new also has a "-n" parameter so if you have the
>     constants correct then perhaps you want the following command:
>     sa4250_ch_new -n 1 -v 56
>
>
> Ok, one more update and please understand I have no idea what I'm doing:
>
> I modified sa4250_ch_new.c and set up that section as follows:
>
> #define SA4200HD_VENDOR_ID1     0x000014f8
> #define SA4200HD_MODEL_ID1      0x00001072
> #define SA4250HD_VENDOR_ID1     0x000022ce  /* jerkychew's stb */
> #define SA4250HD_MODEL_ID1      0x000010cc  /* jerkychew's stb */
>
> I then compiled it using sudo gcc -o sa4250_ch_new sa4250_ch_new.c 
> -lrom1394 -lavc1394 -lraw1394 and moved it to /usr/local/bin
>
> I cd'ed to that directory and ran the following, with the following 
> result:
>
> matt at mythdev:/usr/local/bin$ ./sa4250_ch_new -n 1 785
> Changing channel 785
> matt at mythdev:/usr/local/bin$ ./sa4250_ch_new -v -n 1 785
> node 1: vendor_id = 0x000022ce model_id = 0x000010cc
> Device acquired on node 1
> Changing channel 785
> AV/C Command: cmd0=0x00487ce7 cmd1=0x04031100 cmd2=0xff000000
>
> But it still never changes. Still out of ideas. I downloaded Scott 
> Bickford's script and will try to compile that.
Matt,
You appear to be doing this correctly now and selecting the correct box. 
The output AV/C Command looks correct for your choice.

I think what is happening is your 4250HDC requires a key release after 
the channel changing. Apparently some do.
Follow: http://ubuntuforums.org/showthread.php?t=712789 to the bottom of 
the page and you will see bml137's comment and modification to the code 
you are using.


You could also give a try to Majoridiot's newer universal changer. I 
have not tried it but reading through his code, it looks comprehensive 
and likely addresses this.
See: https://wiki.ubuntu.com/majoridiot

Christian