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Re: [Debconf-video] Advice about a video system

I have set up several setups based on what we did for DebConf - my
main videoteam involvement is from DebConf 6 and 7, and we could say
my methodology forked and continued on its own from there. And even
though I'll be the first to recognize the results from our work are
REALLY far quality-wise from what the DebConf videoteam produces,
price-wise it has been REALLY better. And given the reality of some of
the setups I have worked with, the results are more than agreeable.

So, I'll only comment on the diverging bits.

> Twinpact100 - $500  must have.  converts VGA being projected to a dv
> video stream.

Oh yes. We didn't have one for some time (and also at DebConf, in DC6
and DC7 we had a separate camera pointing at the projection
screen). Quality is BAD. If you are saving for _one_ thing, save for
the Twinpact.

> dv camera(s) - $250 - $2500  (pycon used cheap, debconf expensive)
> Having a 2nd camera for the audience is really nice.

We usually work with mid- to low- range DV cameras. A colleague of
mine reported he was able to sustain a good quality stream with a USB
camera - And thus he expected to be able to do so with webcams. In
this case, we would be using this for reliable, 2xunidirectional, easy
point-to-point videoconferencing (rather than recording), but it might
still be interesting for some.

> (...)
> PC to run DVswitch: $600 ish.  It does not need lots of CPU or ram.
> it needs about 130 gig of drive space for a day of recording.  it
> needs 1 firewire *bus* (not port) for each video source (2 for 1
> camera, 1 twinpact) - most firewire cards only have one bus.  line
> level audio in which will be hooked to the mixer.

This is the point we differ the strongest.

I have decided to do the transcoding in the video station itself. It
raises (although not by so much - A P4 is still more than enough) the
CPU requirements, although I'm sure it will impose a cap on the number
of handled streams - I have stayed with a single stream; at my
workplace, we have an analog video mixer and a analog→DV converter;
when setting up video streams elsewhere, I do single-stream even if
the resulting quality is lower. 

On the happy side, transcoding in the video station has allowed us to
operate on places with poor network infrastructure - Often our only
connectivity option is a shared wireless; once we even set up a stream
-which turned out to be quite reliable- in an network that was about
20 hops off a non-RFC1918 address¹. Preserving the data does not need
130GB a day, but rather around 1% of it, so any modern laptop is more
than up for the task. Of course, this obliterates any possibility of
having a low- and high-quality streams (or recordings).


¹ http://gwolf.org/blog/great-firehole-nicaragua

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