[AG-TECH] Any more H.264 news?
Piers O'Hanlon
p.ohanlon at cs.ucl.ac.uk
Tue Apr 22 04:01:13 CDT 2008
Doug,
On Tue, Apr 22, 2008 at 7:44 AM, Douglas Kosovic
<douglask at itee.uq.edu.au> wrote:
> UQ Vislab vic doesn't have support for IIDC/DCAM firewire cameras (like
> the iSight), just DV/HDV camcorders.
>
Thanks for the clarification - though I thought I'd mention that an
'iSight camera' can be
a misleading reference as Apple seem to call a bunch of their cameras
iSights - however
there are different beasts (these are the two variants I know of):
- The external [firewire] iSight is a DCAM device (i.e. uncompressed video)
- The built-in [USB] iSight on the MacBooks is a high-speed USB device
(using the the uvc driver under linux)
Piers.
> 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
>
>
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