[AG-TECH] HD on AG

Claus Endres claus at endresconsulting.com
Mon Dec 15 02:48:52 CST 2008


Hi Douglas,

Do you know which HD H264 camcorders are supported by the UVC video
driver?

I would be very interested to play around with one...

Regards,
Claus.

Douglas Kosovic wrote:
> Hi,
> 
>>>>> I, too, am extremely interested in vic supporting HD formats, 
>>>>> (including uncompressed!) One of the issues is the encoding latency 
>>>>> problem. Not sure there's a nice low latency encoding solution out 
>>>>> there yet. Alternatively, we might look at cheap hardware encoders 
>>>>> as the answer or HDMI cards to take the input from the camera.
>>>>> Can vic be made to take the output of, say, the BlackMagic Design 
>>>>> HDMI card on a Mac?
> 
> MacOS X UCL vic works out of the box with the BlackMagic Design HDMI 
> capture card, but gets scalled down to 640x480 for the large capture 
> option.
> 
> A quick hack to add 1980x1080 support is to modify the following width & 
> height lines in video/grabber-macosx.cpp :
>    switch (decimate_) {
>                case 1: // full-sized
>                        width_ = SP601_NTSC_WIDTH;
>                        height_ = SP601_NTSC_HEIGHT;
> 
> to: 
>                        width_ = 1920;
>                        height_ = 1080;
> 
> Windows UCL vic on the other hand crashes with the BlackMagic Design 
> HDMI capture card as it currently doesn't support the BlackMagic YUV 
> colorspace.
> 
> I wouldn't mind adding support for USB HD camcorders that support UVC 
> (USB Video Class) H.264 streaming over USB, but I currently don't have 
> access to one. Note: Not all USB based camcorders support UVC (e.g. Sony 
> Hanycams).
> 
>>>>> I am currently using AGDV under windows but would like to move to 
>>>>> linux and use the HDV/DV linux vic for the DV part; i don't think 
>>>>> it's encoding the HDV, just accepting it as input from the camera 
>>>>> already encoded??? [chris?]
>>>>>
>>>> It is possible to just packetise the compressed data from a camera, 
>>>> though as Chris points out it tends to have quite high latency. That 
>>>> is why the ultragrid and derivatives used uncompressed HD as their 
>>>> sources. VIC doesn't currently support mpeg2 nor does support 
>>>> packetisation of an existing compressed mpeg2 stream.
>>>>
>>>
>>> wait, i thought chris' vic supported HDV, which i assume is mp4???
>>>
>> AFAIK most cameras support HDV - which is closely related to MPEG-2:
>> http://en.wikipedia.org/wiki/HDV#HDV_720p
> 
> Mostly just the DV firewire based camcorders, the harddisk USB based 
> ones are now mostly AVCHD (MPEG-4 AVC/H.264).
> 
>>> also, how hard/easy would it be for vic to support packetizing 
>>> uncompressed HD?
>>>
>> Not that hard - one needs to read the [RTP and codec] specs and code 
>> it up - or borrow someone else's....
>>
>> Piers.
>>
>>> :-)
>>>
>>> -gurcharan
>>>>
>>>> Piers
>>>>
>>>>
>>>>> My ideal would be to encode the presenter's laptop output and 
>>>>> deliver that as just another video stream along side the 
>>>>> presenter's video and the audience video and have autoplace lay 
>>>>> them out nicely in a framed window, a la Adobe Connect or similar 
>>>>> products, so the presenter, the slides, and additional commentary 
>>>>> could be nicely recorded for later videoon demand playback.
>>>>>
>>>>> Just my opinion (and need),
>>>>>
>>>>> -gurcharan
>>>>>
>>>>> Piers O'Hanlon wrote:
>>>>>
>>>>>>
>>>>>> Hi Derek,
>>>>>>
>>>>>> In principle VIC should be able encode and decode HD video - using 
>>>>>> one of the codecs that support such resolutions e.g. H.264 or h261as.
>>>>>>
>>>>>> One needs to modify some of the configuration code in VIC to allow 
>>>>>> selection of larger resolutions (ie HD one needs something from 
>>>>>> 720p (1024x720) upwards). And of course an HD source is necessary. 
>>>>>> We don't currently have access to any HD kit so haven't had a 
>>>>>> chance to work on it but anyone is welcome to try!
>>>>>>
>>>>>> Cheers,
>>>>>> Piers
>>>>>>
>>>>>> 2008/10/22 Vine, Derek A <Derek.Vine at usd.edu>:
>>>>>>
>>>>>>> Hello all,
>>>>>>>
>>>>>>> I am doing some research to spec. up a new AG room, and the group 
>>>>>>> with the money is interested in HD video.  I see that The 
>>>>>>> University of Queensland has an HDV/DV VIC for Linux based 
>>>>>>> systems already, but we would like to stay with Windows.
>>>>>>>
>>>>>>> I was just wondering what kind of time frame I can give them as 
>>>>>>> to when HD will be supported in AG on Windows.  In particular, an 
>>>>>>> HD VIC that will  take its video from a capture card with an 
>>>>>>> HD-SDI input, like the one attached in the PDF.
> 
> I didn't see the PDF, what colorspace does it support? If it's YUV 
> 4:2:0, it would probably work with this vic:
> 
> http://www.vislab.uq.edu.au/ag3/windows/vic-20081121.zip
> 
> (which contained a fix for 480i DV white line artifacts)
> 
> Anyway, I started working on adding support for more colorspaces to the 
> Windows code a few weeks ago and I might get back to working on the code 
> soon.
> 
> 
>>>>>>> Thank you in advance for your help.
>>>>>>>
>>>>>>> Derek Vine
>>>>>>>
>>>>>>> Communication Network Specialist
>>>>>>> The University of South Dakota
>>>>>>> 414 East Clark Street
>>>>>>> Vermillion, SD 57069
>>>>>>> (605) 677-8215
>>>>>>> dvine at usd.edu 
> 


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