[mythtv] Thoughts on encoder farms / distributed capturing and viewing

Craig McLaughlin mythtv-dev@snowman.net
31 Oct 2002 08:28:37 -0800

On Wed, 2002-10-30 at 22:29, Robert Middleswarth wrote:
> You are right that 1 Well Comprised Video Signal could be sent from a 
> Video Sever to a Video client without to much trouble. but we aren't 
> talking about that.  We are talking about multipule pc talking back and 
> forth.  So 1 PC could be asked to Xfer Saved data and Xfer Live Data and 
> Receive Live Data using a Codec that was designed for speed not size. 
>  Althought we are talking about 100 based network cards they do start to 
> slow down in the 3-4 Meg range.  Granted if you are talking about 1 
> Machine for Encodeing and 1 Machine that only displayed then yes there 
> would be no problem but that isn't what Mythtv is doing at this time and 
> if I read right not what  Robert Kulagowski was talking about.

100Mbps NICs slow down in the 3-4 Meg range?  What kind of environment
have you seen *that* in?  I've seen that kind of poor performance on
some older machines running Win9x, but my little pentium 166 firewall is
routinely asked to push upward of 30, and handles it just fine...  I
suspect you may be seeing IP stack issues and not hardware issues...

I regularly toss very large datasets around my network here, and often 
saturate my 100Mbps switch without too much trouble (note: my 100Mbps
switch is actually a cheapo one that only has a 200Mbps backplane).

> >A couple of edge cases would need to be done, too -- like moving from
> >the higher-priority "current" to the "new" when the higher-priority one
> >is done (i.e.: at 1902)... Hm.  Yeah, time to get that extra system
> >finished...
> >
> Please note I use the term AI in very generic way.  I think you are 
> right I mis-read what he was asking . :-[   I think you are right about 
> that being rather easy to do althought it opens a few questions about 
> recording on the same channel.  Example how would you handle 8:00 PM 
> Seventh Heaven 9:00 PM Everywood both show are one hour long on the same 
> channel.

If the channel of both shows is the same, then... how about merging the
recording?  One 2-hour block?  Perhaps with some arbitrary split in the
middle, if one really has to have 2 separate files.

> Sorry I wasn't as clear as I had ment tobe.  It is getting late now and 
> I need to get some sleep.  I hope this replay is more clear on what I 
> was tring to say.

I understand, I think; I just happen to disagree.  No offense, of
course.  I think most of what you're concerned about can be handled
quite transparently.  Remember the target audience, too... I would tend
to think that there's a ways to go with Linux, Capture cards, etc,
before MythTV becomes the "barrier to entry."