[mythtv-users] Problem with Hard and Soft Padding on recordings

Michael T. Dean mtdean at thirdcontact.com
Wed Feb 9 03:08:08 UTC 2011


On 02/08/2011 08:11 PM, Nick Morrott wrote:
> On 9 February 2011 01:09, Anthony Giggins wrote:
>> Thanks for the confirmation Nick I'll update the wiki to reflect this
> Note that I'm not a MythTV dev, so maybe Mike Dean will confirm?

That's pretty much correct, except we really don't have "soft padding," 
per se.  Instead, we have what you might think of as a "capture card/HDD 
spin-up/shutdown allowance."

More specifically, the, "Time to record before start of show (secs)," 
setting says, "If this is the first use of this capture card in a while, 
start recording this much early so that hard drives can spin up or 
slow-to-init capture cards that require firmware uploads can complete 
before the scheduled show begins," or whatever. (And, really, I the, 
"Time to record past end of show (secs)," setting is probably more for 
symmetry than anything else--I'm not really sure what use it could be in 
the context of how it's actually applied.)

So, remember, they're capture card related than recording related.  If 
your capture card is being used for the entire block of primetime, they 
say, "Start this capture card 30s before primetime and keep the card 
running 30s after primetime."  (Or whatever.)

The settings are not meant as a means of capturing the end of a 
show--that's what the per-recording rule start early/end late ("hard 
padding") are for.  It's meant to be a relatively small value (20-30s), 
but for years, it's been abused (OK, maybe I should say, "misused") as a 
kind of super-unreliable "soft padding," probably more because people 
figure, "Why not?" than because it's useful this way.

Note that I'm purposefully not using the term, "soft padding," to refer 
to the settings, "Time to record before start of show (secs)," and, 
"Time to record past end of show (secs)," because, "soft padding," 
implies behavior we don't have.  For example, if you have a recording 
scheduled at 8:00-9:00 and another at 9:00-10:00 and you have 2 capture 
cards and set these settings to 30s each, you'd use 1 capture card to 
record the first show from 7:59:30 - 9:00:00 and the same capture card 
to record the second show from 9:00:00-10:00:30.  Whereas, saying, "soft 
padding is only applied when it can be," would imply that we would 
actually use 2 different capture cards for the recordings and each would 
have 30s extra before and after the show--because a soft padding /could/ 
have been applied to both recordings.  So, because of that, I feel, 
"soft padding," is a terrible word for describing these settings.  
Unfortunately, "Time to record before start of show (secs)," and, "Time 
to record past end of show (secs)," are extremely long, cumbersome names 
for them (and not really descriptive of their true purpose, even).  But, 
until someone comes up with a good name for them...  (And I am way too 
lacking in creativity to do that.)

And, for more details than you could possibly want on why we don't have 
soft padding--or, more correctly, why soft padding can't possibly 
work--read (all 5 pages of) 
http://www.gossamer-threads.com/lists/mythtv/dev/195124#195124 .  :)

Sorry.  This turned out to be a lot more verbose than I intended--but I 
suppose that complexity is exactly why these are probably our most 
misunderstood settings.  (Granted, the bad naming doesn't help, either. :)

Mike


More information about the mythtv-users mailing list