[mythtv] SVN8501 LiveTV via firewire

Steve Adeff adeffs at gmail.com
Thu Jan 5 22:05:10 UTC 2006

On Thursday 05 January 2006 16:17, Jeremy Muhlich wrote:
> On Thu, 2006-01-05 at 15:51 -0500, Steve Adeff wrote:
> > I also need to see if those glitches occur when not running through
> > firewire to see if its just the firewire output. This scenario wouldn't
> > surprise me, as I'm also trying to figure out why it will only output a
> > data stream on one of its ports, and sometimes it swaps which port it is.
> > Funny thing is, it doesn't care for channel changes...
> Is it really swapping which jack it outputs video on, or might some
> state just getting reset when you unplug/replug the cable?  Can you
> replug into the same jack instead of swapping and get video again?

I'm fairly sure I tried this, but next time it happens I will definitely do 
this and log what happens.
I noticed this on my dad's 62xx series DVR, one jack would only let me do 
channel changes, the other would only let me do video capture. I don't 
remember if they ever swapped, but I only used it in limited amounts when I 
was visiting the folks.

> Note that when the linux1394 code references a "port" it really means
> "host adapter".  I.e. if you have two separate 1394 chips/busses on your
> motherboard, or one onboard and one on a PCI card, then you would have
> two "ports".  Two jacks that are controlled by one chip are not two
> "ports".   I don't think the jacks can even be differentiated, at least
> in software.  I'm not sure what the official 1394 terminology is, but
> this usage of the word "port" is very confusing.

Ok, according to plugreport...
Host is the chipset. I have two Hosts, one is a VIA that refuses to work, the 
other is an NEC that has worked wonderfuly for me so far.
Node is the Jack on the Host. I have 3 on one of my hosts and 1 on the other.

I'll use this terminology since plugreport should have the terminology 
correct, and if not, all firewire users use it so might as well go with it.

> Your cable box may have two jacks, but there's certainly only one 1394
> chip driving them both.  Thus it would be pretty odd (and certainly
> broken) if the firmware could manage to output to one jack
> preferentially.

I agree, but that's what looks to be happening... I'll report back...


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