[mythtv-users] channel changes via script suddenly stopped working--diagnose help

[Larry Roberts]

On 4/14/2013 10:34 AM, Peter Bennett (cats22) wrote:
> On 04/14/2013 03:21 AM, Paul Wootton wrote:
>>> So I did a full upgrade to the latest and greatest of packages,but no success.  I then decided I needed to see more of what the script was doing so I added a 3 second pause at the very beginning of the script.  BLAM its working again.
>>> I did 5 test recordings from mythweb and all picked the right channel.  I dont know if its a long term fix, or for that matter why a 3 second pause at the beginning would make a difference but it seems too!
>>>
>>> I was able to see the channel change taking place during the video and it was sending a single character each time.  Again I dont know if the 3 second pause really made a difference or if I just managed to scare a gremlin out of the sytem but I'm not going to remove the pause to find out !
>>>
>>> Everyone please cross your fingers and toes!   Thanks for the help in troubleshooting this as well.  I learned a bunch about linux in the process which makes it worth it!
>>> _______________________________________________
>>> mythtv-users mailing list
>>> mythtv-users at mythtv.org
>>> http://www.mythtv.org/mailman/listinfo/mythtv-users
>> I always find it a bit scary to not know why something starts working, but I understand why you'd want to leave it alone.  On the other hand the learning more about Linux is never a bad thing
>>
>> Cheers
>> -- Paul --
>>
> For what it's worth - I had a lot of timing problems and missed digits
> when setting up irsend. What I have now works 100% of the time:
>
>      commands=$(echo $channum | sed -e 's/./& /g')
>      for digit in $commands; do
>          irsend  send_once $REMOTE_NAME $digit
>          sleep 0.4
>      done
>      irsend  send_once $REMOTE_NAME SELECT
>
> Send 1 digit at a time with 0.4 seconds delay, then send SELECT after
> another 0.4 seconds delay.
>
> Another thought - perhaps something mythtv is doing while invoking the
> script is using excessive CPU for a second or two, interfering with the
> timing. By putting in the 3 second delay you may have delayed until the
> heavy CPU period is over. How powerful is your CPU?
>
> Peter
>
I may have spoke to soon.  I just had a recording miss its channel, and 
it wasnt even close.  It not a very powerful CPU, Pentium 4 2.00Ghz and 
3Gb of RAM.  While nothing new I am doing software raid on the box but I 
write all my data to a CIFS mount  I increased the delay additionally so 
I can see more of what is being sent.  Luckly for me comcast will show 
on screen what numbers its receiving so I can see what its getting.  I'm 
afraid its going to be one of those hit or miss things.

I would say that I'm kicking off a test job from the mythweb to do my 
testing which works fine.  It was the prescheduled recording that 
missed.  I would think that mechanism would be identical but for the 
sake of completeness of info I thought I should include it.