[AG-TECH] Any more H.264 news?

Douglas Kosovic douglask at itee.uq.edu.au
Tue Apr 22 01:44:10 CDT 2008


UQ Vislab vic doesn't have support for IIDC/DCAM firewire cameras (like
the iSight), just DV/HDV camcorders.

There is an alpha version of UQ Vislab vic available for Windows, from:
http://www.vislab.uq.edu.au/research/accessgrid/software/advideo/windows
.html

unlike the (non-alpha) Linux version, there are issues with it, on an
old Dell Optiplex GX620 (dual core 3.4GHz P4) the PC grinds almost to
complete stop, on faster Intel Core-2 CPUs (including Core 2 based Xeon)
the PCs have acceptable performance. The performance issue was with 576i
DV which has a YUV 420 colour space, it mightn't be an issue with 480i
DV, which has a YUV 411 colour space.

Changing topic back to UCL-VIC. WinXP ships with an DV directshow filter
by default. I captured the following screen dumps of the vic that comes
with the H264VideoProducer of the AG 3 All-in-One Installer:

  http://www.itee.uq.edu.au/~douglask/DV.png
  http://www.itee.uq.edu.au/~douglask/HDV.png

I selected 'Large' and 'MPEG-4, as you can see, there are no white
vertical lines with either DV or HDV sources, but that could be because
I'm using a 576i DV and 1080i HDV sources rather than 480i DV which uses
a different YUV colour space. On a MacPro (2 x dual core (core-2 based)
2.6GHz Xeon) running WinXP, VIC was using close to 90% CPU on one of the
cores for 576i DV.


Cheers,
Doug

> -----Original Message-----
> From: owner-ag-tech at mcs.anl.gov [mailto:owner-ag-tech at mcs.anl.gov] On
> Behalf Of Piers O'Hanlon
> Sent: Tuesday, 22 April 2008 10:19 AM
> To: ag-tech
> Subject: Re: [AG-TECH] Any more H.264 news?
> 
> Hi folks,
> 
> I thought I'd just clarify a couple of things relevant to the Firewire
> camera discussion - There are two basic types of the firewire cameras:
> - AVC - DV 'handycam' video camera - which provide DV compressed
> video, usually with audio
> - DCAM - simpler devices that just provide uncompressed video
> 
> (for more details see: http://en.wikipedia.org/wiki/FireWire_camera)
> 
> The support for these cams aries under windows, and Linux
> - Under linux there's different respective support libraries (libdc,
> libavc) to directly bring in the two different types of video - there
> are also higher level apps that can convert DCAM (coriander) and AVC
> (DV4Linux) video streams to video4linux - they seem to work but are a
> bit flakey at times. As far as UCL-VIC goes there is an alpha driver
> for DCAM video which currently doesn't really work, and there's no
> support for AVC cameras. On the decode side there also alpha support
> for DV decode which also doesn't quite work (anyone is welcome to
> debug these - we only have limited time...). I understand that the VIC
> from UQ DOES have support for AVC devices but I'm not sure if handles
> DCAM devices.
> - Under Windows I have tested a DCAM device successfully but that
> doesn't mean they all work (though they should do). I have not tested
> an AVC device as yet but I suspect there may be problems (as mentioned
> on the list e.g by Andrew Rowley). In theory the Direct Show Windows
> capture should be able to create a filter-graph that would need to
> include a DV-to-YUV converter (DS filter) but I'm not clear if this is
> actually happening (or that Windows ships such a DS filter...). I
> don't know whether the UQ VIC supports DCAM/AVC under windows
> separately?
> 
> Piers.
> 
> 
> On Tue, Apr 22, 2008 at 12:12 AM, Nathan Gardiner
> <nathan.gardiner at canterbury.ac.nz> wrote:
> > Hi Andrew,
> >
> > I have come across this before. Are you using the extended video
> > producer for windows? If you are then it doesn't work with PAL
> > cameras (which UK, Australia and NZ etc use).
> >
> > In regards to the UQ vislab DV / HDV services, under my ubuntu box I
> > had a similar problem until I installed a fairly up-to-date NVidia
> > Graphics card and drivers. (I am currently using an 8800 card).
> >
> > Hope this helps.
> >
> > Regards,
> > Nathan
> >
> >  ________________________________
> >  From: owner-ag-tech at mcs.anl.gov [mailto:owner-ag-tech at mcs.anl.gov]
> On
> > Behalf Of Andrew Rowley
> > Sent: Monday, 21 April 2008 10:32 p.m.
> > To: Andrew Ford; Douglas Kosovic
> > Cc: ag-tech
> > Subject: RE: [AG-TECH] Any more H.264 news?
> >
> >
> > Hi,
> >
> > I have tried firewire capture on windows and get similar results - I
> > just get a kind of set of lines (see attached image).
> >
> > I have a feeling that this is due to vic assuming that the camera
> > source is a standard size (e.g. 352x288) when it isn't.  It looks
> > like it is picking up an image from the camera (it changes when I
> > move around in front of the camera) but it is only using some of
> > that image (I think).
> >
> > This was using a Sony MiniDV camera.
> >
> > Andrew :)
> >
> > ---------------------------------------------------------
> >
> >   Andrew G D Rowley
> >   Senior Development Officer
> >
> >   Research Computing Services
> >   The University of Manchester
> >   Kilburn Building, Oxford Road
> >   Manchester, M13 9PL
> >
> >   t :  +44 (0) 161 275 0685
> >   e :  Andrew.Rowley at manchester.ac.uk
> >   w :  www.manchester.ac.uk/researchcomputing
> >
> > ---------------------------------------------------------
> >
> >  ________________________________
> >
> >
> > From: owner-ag-tech at mcs.anl.gov [mailto:owner-ag-tech at mcs.anl.gov]
On
> Behalf
> > Of Andrew Ford
> > Sent: 18 April 2008 21:21
> > To: Douglas Kosovic
> > Cc: ag-tech
> > Subject: Re: [AG-TECH] Any more H.264 news?
> >
> > On Wed, Apr 16, 2008 at 8:54 PM, Douglas Kosovic
> <douglask at itee.uq.edu.au>
> > wrote:
> >
> > UQ Vislab vic doesn't do any transcoding from DV (or HDV) firewire
> > devices to other codecs, so if the codebase was merged as it stands
> > now, it wouldn't do what you are trying to do anyway.
> >
> > Well, doing raw DV without transcoding would be fine (if it were on
> > both platforms), since we can spare the bandwidth - that's what
we're
> > already doing via the ExtendedVideo services on Windows, but we'd
like
> > to be able to move on to something more cross-platform.
> >
> > Have you tried using DV4Linux so that your Camcorder can be seen as
a
> > V4L device? I haven't tried it myself.
> >
> > Interesting, I'll have to try that out. Would vic theoretically be
> > able to transmit 640 (or 720)x480 video from a V4L device?
> >
> >
> > As for the flashing verticle line artifacts on Windows, I don't seem
> > them, but I was using a quad-core 2.6GHz Xeon.
> >
> > We've seen it here on a couple of different systems - a Dell w/ a
> > dual-core + hyperthreading 3.46Ghz CPU, and Suns with 2x dual-core
2.2Ghz
> > Opterons - so I doubt it's CPU-related. Can anyone else chime in if
they've
> > tried the firewire capture on Windows?
> >
> > --Andrew




More information about the ag-tech mailing list