<div class="gmail_quote">On Sat, Feb 12, 2011 at 4:16 PM, Michael T. Dean <span dir="ltr"><<a href="mailto:mtdean@thirdcontact.com">mtdean@thirdcontact.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;">
<div class="im">On 02/12/2011 06:17 PM, Yeechang Lee wrote:<br>
> If 0.24 has functionality that prevents the issue from occurring I am<br>
> glad to hear it as I am still on 0.23. What does setting the timeout<br>
> to 10 seconds do? Is it a delay between channel changing and<br>
> attempting to lock on the signal? If so I imagine it would make using<br>
> live TV painful.<br>
<br>
</div>For the first time, ever, MythTV 0.24+ monitors external channel change<br>
progress so that it can determine when to begin recording, even for<br>
long-running channel-change scripts. With earlier versions of MythTV,<br>
if you had a channel change script that could run for more than a second<br>
or 2, you'd have to background the script--so mythbackend starts<br>
recording immediately, even before channel change was complete--and hope<br>
that everything worked out.<br>
<br>
The HD-PVR, though, is very temperamental and if you began recording<br>
before it had gotten a "lock," it would cause problems. Therefore, John<br>
Poet wrote code to monitor the channel change script and start recording<br>
once it completes.<br>
<br>
If you set the timeout to 10s and your external channel change script<br>
takes 0.00005 seconds to complete, mythbackend will start recording<br>
after 0.00005s (well, plus a few ms or whatever it takes since nothing<br>
is instantaneous :). If your channel change script takes 9s, though--as<br>
can happen for an HD-PVR to become ready to record under some<br>
circumstances--mythbackend will wait until the device is ready before<br>
beginning to record. In other words, nothing changes as far as the<br>
performance of the HD-PVR or channel changes with the HD-PVR, but rather<br>
than have a built-in "wait a few seconds just in case", we can start<br>
recording as soon as the device/drivers are ready (which will, in<br>
general, likely be around the same wait time as with the previous<br>
hard-coded wait, but could be shorter or longer in some circumstances).<br>
<br>
The reason I mentioned the timeout is because since that timeout value<br>
was never used before for capture using inputs that required external<br>
channel change scripts, users who upgrade their databases from previous<br>
versions may have invalid/incorrect values for the timeout for their<br>
devices/channel change scripts. Therefore, anyone who uses an external<br>
channel change script and upgrades to 0.24 should verify the values are<br>
sensible.<br>
<br>
That said, if you upgrade to 0.24-fixes from this Thursday or later, you<br>
will almost definitely see /much/ faster and more reliable Live TV and<br>
playback startup, and possibly faster channel changes in Live TV, thanks<br>
to some great work done by Mark Kendall and Taylor Ralph. I highly<br>
recommend the upgrade--especially for Live TV users.<br>
<br>
Note, though, you need a /very/ new 0.24-fixes.<br>
<br>
Mike<br>
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</div></div></blockquote></div><br><div><br></div><div>Just for reference, I'm on 0.24 and have the HDPVR issue we are discussing.</div>