[Elphel-support] Some questions regarding the stereo/3D turn key camera

[Sebastian Pichelhofer]

Hi Doron

On Wed, May 18, 2011 at 19:34, Doron Nakar <doron at cellsory.com> wrote:
> Hi,
>
> Before we start a project based on the Elphel camera, we need to have
> crucial information for basic application matching.
>
> I understand that the mailing list is the best support option, so here are
> my questions:
>
>
>
> regarding model: NC353L-359-STEREO
> 1) Our application requires low latency (close to real time). considering
> the other aspects (of bit rate & 3D HDTV image quality), what latency can I
> achieve with this camera? is it possible to have it ~1 frame?

With VLC we get latencies at FullHD of around 40-50 ms which is also
the frame period of a single frame.

be sure to use the vlc parameter: --rtsp-caching= integer in ms

http://wiki.videolan.org/Live555

> 2) Since we use the camera for real time streaming purposes it is very
> important to limit the maximum bit rate or use it in constant bit rate mode.
> is this supported (maximum bit rate)? can we expect 3D HDTV quality in
> 8-12Mbits?

What is "3D HDTV quality"?

You can freely adjust the JPEG compression ratio from 0-100% and
therefore affect the datarate.

12Mbits is rather low, I don't think you will get good video quality
at this low datarate.

Elphel cameras are designed for high datarate, high quality video. The
Ethernet bottleneck is 100Mbit.

> 3) What is the typical/stand by/maximum power consumption of the module? can
> it use a single Li-Ion battery voltage supply (3.6v)?

Power consuption:
http://www3.elphel.com/importwiki?title=10349

Battery pack options:
http://cinema.elphel.com/en/battery


> 4) does the encoding module support h264? If not, is Ogg Theora good enough
> (for the stated bit rate & latency requirements)?

H264 is a proprietary codec and is not supported.

Ogg Theora implementation was discontinued in Elphel cameras a few
camera versions back.

The currently supported codec is MJPEG.


> 5) What typical image quality can we expect from the sensor/lens
> combination? do you have sample footage for the NC353L-359-STEREO?

The stereo setup is just 2 Elphel NC353L sensor front ends combined.
So you can look at normal Elphel353 image samples:
http://wiki.elphel.com/index.php?title=353#Sample_images_and_videos_captured_with_Elphel_Model_353_camera

> does it have an image stabilizer HW/SW?

no.

I guess you can use lenses that have stabiliation built in though.


Hope this helped.

Regards Sebastian

>
>
>
> I would be glad to clarify any issue regarding the questions in case some
> are not clear enough.
>
> Thanks in advance,
>
> Doron
>
>
>
>
>
>
>
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>