[Elphel-support] Asking the technical help

Tue Nov 15 17:57:03 PST 2011

Andrey,

Just see your explanations after flying back from DARPA's BAA review
meeting. We will digest your information, try it experimentally. 

Best regards,

Guanghai

Dr. Guanghai Jin

VP of R&D, Chief Scientist

Phone: 781-935-1200 ext 124

Fax: 781-935-2040

Agiltron, Inc

15 Presidential Way

Woburn, MA 01801

www.agiltron.com

From: elphel at gmail.com [mailto:elphel at gmail.com] On Behalf Of Andrey
Filippov
Sent: Tuesday, November 15, 2011 12:31 PM
To: GuangHai Jin; support-list at support.elphel.com
Subject: Re: [Elphel-support] Asking the technical help

On Tue, Nov 15, 2011 at 3:26 AM, GuangHai Jin <gjin at agiltron.com> wrote:

Hi Andrey,

I understand you as our company grows up from a small company as well. Thank
you very much for your kind help to consult us. I have a few basic questions
per your answers.

1) First of all you have to keep the window height constant....

Does it means that the dynamic small window should have the format as
X.vs.1936 such as 250x1936 from the 2592x1936 sensor? 

GuangHai,
No - it does not need to be exactly 1936 - just don't change between the
frames

As the full frame rate of your camera can realize 14fps with JP4 raw, does
the maximum frame rate might reach up to 140fps approximately for 250x1936
small window?

It would be almost correct if you reduced the height (1936), not the width
(2592) of the sensor WOI. The sensor has some minimal blanking - vertical
and horizontal, the exact numbers are in the Aptina datasheet (available on
their web site). The vertical one is small (8 lines if I remember
correctly), so reducing frame from 2592*1936 to say 2592*192 (each dimension
should be multiple of 16) will give you (1936+8)/(192+8)= 9.72 gain in fps.
On the other hand, horizontal blanking is much larger - several hundred of
pixels, so reducing frame width has lesser effect on the FPS. This large
horizontal blanking time is caused by the need to transfer analog signals
from the selected line of pixels to the array output multiplexers (they are
not interleaved).

If on the camera home page you select "Parameter editor" (or just go to
http://camera_ip/autocampars.php) you can select "woi" (second line) and
then open the link "View/edit Current". Among other parameters it will show
"VIRT_WIDTH" and "VIRT_HEIGHT" that camera calculates for the WOI according
to Aptina specs. in some cases it is possible to modify these values keeping
the sensor operational (i.e. reduce VIRT_HEIGHT)

Additionally, for the really high FPS you may want to use the special camera
mode that allows combining several actual frames into one output frame. In
this mode you can combine even 2-pixel high "frames", converting the camera
into a virtual line-scan device (
http://blog.elphel.com/2010/11/elphel-as-a-line-scan-camera-for-river-panora
mas/ ). While the camera compressor itself is limited to average pixel rate
of 80 MPix/sec in JP4 and 53MPix/sec in JPEG, the recorded frame rate can be
limited fy the network or recording to HDD, SSD or CF (limited by the ATA
implementation in the processor). Each compressed frame has the Exif
metadata attached - while it is negligible in size fro the large frames, it
can be relatively large for the small one, each frame causes frame interrupt
and some software activity. So when the FPGA combines several small frames
into one (with the single Exif header, single frame CPU interrupt), you can
get higher FPS in the cases when it is network/CPU bandwidth-limited. Or be
able to record higher quality (less compressed) fro the same FPS.

Andrey

Thanks again,

Guanghai

Dr. Guanghai Jin

VP of R&D, Chief Scientist

Phone: 781-935-1200 ext 124

Fax: 781-935-2040

Agiltron, Inc

15 Presidential Way

Woburn, MA 01801

www.agiltron.com

From: elphel at gmail.com [mailto:elphel at gmail.com] On Behalf Of Andrey
Filippov
Sent: Monday, November 14, 2011 12:30 PM
To: GuangHai Jin; Elphel Support List

Subject: Re: [Elphel-support] Asking the technical help

Hi Guanghai,

We will be happy to consult your engineers, but unfortunately we can not
work on such project as a contract job. We are a small company and all our
resources are used by our current projects.

Andrey

On Sat, Nov 12, 2011 at 8:33 AM, GuangHai Jin <gjin at agiltron.com> wrote:

Hi Andrey,

Thank you so much for your clear explainations. It's very helpful for me to
decide which technical way we will chose. Our engineers will dig in the
details by following your instruction. Meanwhile, I am wondering if your
company would take this job as a contract for us.

Thanks again and have a good weekend,

Guanghai

Dr. Guanghai Jin

VP of R&D, Chief Scientist

Phone: 781-935-1200 ext 124

Fax: 781-935-2040

Agiltron, Inc

15 Presidential Way

Woburn, MA 01801

www.agiltron.com

From: elphel at gmail.com [mailto:elphel at gmail.com] On Behalf Of Andrey
Filippov
Sent: Friday, November 11, 2011 1:26 PM
To: GuangHai Jin; support-list at support.elphel.com
Subject: Re: [Elphel-support] Asking the technical help

Hello Jason,

I'm sorry - we had a problem with the mailing list and I missed that your
previous email.

Yes, it is possible to dynamically re-program the small window, to the
extend it is supported by the sensor.

1) First of all you have to keep the window height constant - changing it
may cause sensor to output bad frame and it will be skipped by the camera.

2) There is a lag between sending the window parameters to the sensor, the
output of the new frame and compressing it in the camera (when you get the
frame and can analyze the objects there. The camera supports pipeline
modification of the parameters, when you provide the new values you also
specify to what frame it applies. On the hardware level the parameters are
stored in an 8 element circular buffer - the software driver places the new
values there and the FPGA code applies them to the compressor and send to
the sensor at appropriate time. The default "program ahead" (if you do not
specify when the new parameters should be applied) is 3 frames, but you can
change that in the php function call.

The PHP functions only allow you to program within the capacity of the
hardware buffer (up to 5 ahead, as of 8 elements others are kept after the
frame), but using parsedit.php - called directly or through autocampars.php
you can experiment with other program-ahead times, the software extends the
hardware command buffer. The parsedit.php allows you to open 9 (that number
can be changed) last images, each image has the image number, timestamp and
parameters, so you can verify if any images are lost or corrupted).

Andrey

On Fri, Nov 11, 2011 at 7:17 AM, GuangHai Jin <gjin at agiltron.com> wrote:

Dear Andrey,

About one month ago, I sent you the e-mail to ask your help regarding the
technical feasibility on your FPGA based camera, see the following e-mail. 

Could please you reply me kindly?

Best regards, 

Dr. Guanghai Jin

VP of R&D, Chief Scientist

Phone: 781-935-1200 ext 124

Fax: 781-935-2040

Agiltron, Inc

15 Presidential Way

Woburn, MA 01801

www.agiltron.com

From: GuangHai Jin [mailto:gjin at agiltron.com] 
Sent: Wednesday, October 05, 2011 11:24 AM
To: 'Andrey Filippov'; 'support-list'
Subject: [Elphel-support] Problem in using of LiveDVD

Hi Andrey,

We purchased your network cameras to build our detection system for checking
a single object's lateral motion at a refreshing rate about 10/s. The next
goal is to increase the refreshing rate (>100/s) of the object's position
(x, y). My questions are

1)      Is it possible to dynamically reconfigure a small date (ex. 320x240)
window for high refreshing rate in your network camera around the object as
it moves?

2)      If "yes" in question 1, could we assign this kind of job to your
company as a project contract?

3)      Do you have any recommendation? 

Thank you very much in advance, and looking forward to hearing from you.

Dr. Guanghai Jin

VP of R&D, Chief Scientist

Phone: 781-935-1200 ext 124

Fax: 781-935-2040

Agiltron, Inc

15 Presidential Way

Woburn, MA 01801

www.agiltron.com

From: Jason Chen [mailto:jianzhong_chen at agiltron.com.cn] 
Sent: Thursday, September 15, 2011 6:35 AM
To: Andrey Filippov; support-list
Cc: jianhuiye; GuangHai Jin
Subject: Re: Re: Re: [Elphel-support] Problem in using of LiveDVD

Hi, Andrey,

This time I removed the "sudo" from the front of "netboot", it looks like
program ran some but I'm not sure if the camera is OK now.

Regards

Jason Chen

_______________________________________________
Support-list mailing list
Support-list at support.elphel.com
http://support.elphel.com/mailman/listinfo/support-list_support.elphel.com

_______________________________________________
Support-list mailing list
Support-list at support.elphel.com
http://support.elphel.com/mailman/listinfo/support-list_support.elphel.com

_______________________________________________
Support-list mailing list
Support-list at support.elphel.com
http://support.elphel.com/mailman/listinfo/support-list_support.elphel.com

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://support.elphel.com/pipermail/support-list_support.elphel.com/attachments/20111115/9049b900/attachment-0002.html>