27 Jul
2014
27 Jul
'14
6:55 p.m.
Date: Sun, 27 Jul 2014 08:56:53 -0700
From: len(a)ovenwerks.net
To: dj_kaza(a)hotmail.com
CC: linux-audio-user(a)lists.linuxaudio.org
Subject: Re: [LAU] live video switching? WAS: Re: VJ / VeeJing software alternatives
On Sat, 26 Jul 2014, Kaza Kore wrote:
I assume you mean analogue video (often a yellow phono) rather than digital, SDI out of
your camera? (Min = Googling...)
Yep as expected: Video output (PAL/ NTSC) (integrated with USB terminal) so you would need
an oldschool capture card for that, and audio separately (although on same card and you
have minijack out.) Lower quality, cheaper, not sure of any with Linux capacity for
streaming into other programs though (most seem to do internal mpeg and stuff...)
HDMI mini
output (HDMI-CEC compatible) You can be pretty certain the HDMI contains audio though so
will want an HDMI card. I've only had experience of PCI)e) personally but as you say
they claim Linux support for the range.
Not video switching, and if all your video
sources are going to be consumer
products it may be of no interest to you, but the BBC has done a fair amount of
research and development into tapeless production on Linux over the years. Mainly
multi-channel recording, using prosumer Blackmagic card giving up to 4x SD
in/outs.
Actually, my consummer Canon 60D has no video over USB, but does have both
video out and hdmi out. So these cards are certainly a working solution.
The cost compares very favourably with many of the audio cards
mentioned/recomended on this list too. with a single i/o starting at $145
and four channel i/o still less than $1000 (manufacture's recommended
price). For PCIe, there are also USB3 and Thunderbolt (AKA firewire with a
converter? I have noticed all the new firewire audio IF call themselves
Thunderbolt compatable with an adaptor)
And it seems once again I am behind in my knowledge of
new video standards
(probably old by now) Both this product as well as the Rohde & Schwarz
stuff talk about audio embedded in the video. 16 channels AES/EBU (8
pairs) per video channel. Maybe this is another audio interface solution
as well. (the box for embedding would be somewhat pricy $1000 for aes in
then ADCs to feed that... USB2 with an ADAT would be way cheaper for the
same channels)
HDMI should get around this.
Best of all, both products proudly display that they
have both drivers and
SDK for Linux. The Blackmagic says they are open standard capture cards
and that the SDK is free (maybe not open?). It appears that the target
audience for these products are used to doing their own inhouse software
to use them.
The recommended system to run them on does not seem above midrange for a
home system. It seems many of these cards do some switching/keying on the
card. I would guess this includes fades as well.
True and true. Good luck :)
Dale
--
Len Ovens
www.ovenwerks.net