[PLUG-AV] encoding talk atm & next workshop notes

[James Bromberger]

On 10/08/2011 11:03 AM, Jason Nicholls wrote:
> I'm encoding the luakit talk with x264 like previous talks, this time
> it's doing it at ~50fps thanks to the new quad-core CPU in AV2.
> Previously we'd be between 5 and 10fps - so pretty massive step up :)

Wonder if its possible and worth having one core doing the x264 encoding
in real time then? Hence the video file is ready for upload by the time
we pack away.


> Also last night the system was doing nicely with only 2 CPUs loaded
> between 30-50% and the other 2 idle. It was a bit jumpy since I was
> also doing other things like watching the stream in firefox or vlc
> etc... Overall much better since the old box both CPUs were pretty
> much pegged the whole time (and it only had 2 CPUs).


> For the next workshop:
> - figure out what happened to AV4, with the dead video
> - document using the audio mixer, although we need to buy the
> following bits first:
>   large mono M jacks (left/right) to small stereo M jack (main out of
> mixer -> computer)
See pic to confirm part:
http://www.amazon.co.uk/3-5mm-Stereo-6-3mm-Jacks-Adapter/dp/B003NF5OLO

>   small mono F jack to large mono M jack (wireless mic -> mixer)
> (probably best to get a couple of these)
http://www.amazon.co.uk/Metal-Stereo-Socket-6-35mm-Adapter/dp/B003OSXND6/ref=sr_1_8?s=electronics&ie=UTF8&qid=1312947261&sr=1-8

>   (optional) L & R large M jacks to small stereo F jack (control room
> out of mixer -> for headphones)
(Or the above main out -> computer + a 3.5mm F-F gender bender?)

> - look at different options for ffmpeg2theora for live streaming, now
> we have more CPU headroom we can play around to get better image /
> better compression

Perhaps two encodings? One optimised for small links (10fps, QVGA
320x240, mono, targeting 50 kbps), and one for high bandwidth (25 fps,
PAL 768x576, mono HQ, targeting 1 mbps). So long as the two video
streams combined don't exceed a normal DSL upload speed that we can
expect at many venues.

> - look at fitting a better vid card into AV2, atm the ancient card in
> there only supports a single XV window so trying to run DV Switch and
> watch the stream with VLC or mplayer results in horrible screen
> performance...
Any one got any spares? Or recommendations for something made in the
last 5 years and under $50 or so?

  James

-- 
/Mobile:/ +61 422 166 708, /Email:/ james_AT_rcpt.to
PLUG President 2011: http://www.plug.org.au <http//www.plug.org.au>
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