In message <20030726165347.GA57541@xxxxxxxxx>, Geoffrey Espin
<espin@xxxxxxxxx> writes
Are there Linux drivers for Analog Devices' ADV601 or VideoPipe?
For a device that's been out apparently for years, there's very
little info about, it seams.
Geoff,
Declaration of interest: I consult on ADV601 and, on a small scale,
manufacture PCI cards using this device (see sig).
The ADV601 (and its later derivatives) have been successful in various
embedded markets, especially the security CCTV field where I have been
mostly involved. Many of the big names in this field have ADV601/wavelet
products and still offer them alongside more recent MPEG based systems
(not just for historical reasons - Wavelet has certain advantages). As
the ADV601 does not use inter-field coding it is best compared to
JPEG/MJPEG where IMHO the ADV601 is superior.
It has not really caught on in the general market, which is a great
shame. I think there are 2 main reasons for this:
Firstly, Wavelet coding is not standardised and has no support in common
applications, so there is a problem if you need to view images outside
your own application or system. In a "closed" system such as the CCTV
game, this is not so much of an issue. Where image export is required,
either a wavelet viewer mini-app (usually for Windows) is exported with
the data, or the video data is transcoded to a standard format.
The product you mention from Aware is an excellent ADV601 display filter
for the Windows world, but IMHO prohibitively expensive. Last time I
looked they were not doing anything for Linux. Possibly because the
Linux multimedia architecture seems rather fragmented and it is unclear
what exactly they could provide that would have general appeal.
Secondly, I think Analog Devices never really supported their device
adequately. They had an open-source PCI card reference design (the
Videolab) produced by several manufacturers, with a monolithic Windows
"driver" and app. The card design itself was rather iffy and although
adequate to demonstrate the chip, the driver could not be used with real
user apps. The "Videopipe" which you mention was (is?) just a standalone
demo product using 2 ADV611 devices back to back.
I'm sure that if AD had come up with "proper" drivers and wavelet decode
filters/utilities (we're talking Windows here, 1996/7) then they would
have got a bigger foot in the door.
But to answer your original question... what's happening in Linux? Many
of the commercial DVR systems are Linux based, for which the
manufacturers have produced in-house hardware and drivers.
On the open market, there are several manufacturers of ADV601 PCI cards,
(you can easily find them by Googling) but AFAIK only Integral offer
Linux support. I have no personal experience of them but the card is
well regarded in the Windows world, if rather expensive. The Linux
driver appears to consist of some basic source code, all the ADV601
specific stuff being in the form of object code for the on-board DSP
device. Thus you have no access to the inner workings (arguably a
blessing!)
Then there's me, if I may be permitted a small plug. My cards come with
full source code for a simple (read/write/ioctl) interface for encode
and/or decode. For the sort of stand-alone apps where these cards are
used, the complexity of VfL is not really necessary.
I have been contemplating doing a Video for Linux port for some time but
am dubious about what benefits this confers, since the (wavelet) video
content will be meaningless to standard VfL apps. It seems to me that as
Linux does not a common multimedia architecture then wavelet support
would have to be added on a per-application basis.
I'd appreciate any comments. Having lurked on this group for ages, this
is the first time I have seen ADV601/wavelet mentioned. Would there be
any interest in VFL ADV601/wavelet support?
Hope this has been of interest, always happy to assist with wavelet
questions within my humble abilities.
--
Alan Hall PC and Embedded Systems Design
Databuzz, Ipswich, UK Digital Video Specialist
http://www.databuzz.co.uk "Tsunami" Wavelet Compression Products
