Stereo vision on BB

Is it possible connect two webcams to BB?

yes it is, people have used a variety of usb webcams
with the BB...

Hello,

        Just ensure that you keep the frame rate and resolution low
enough to not exceed the bandwidth of USB2.0.

Cheers,

Neil

I have tested the C2 with two identical webcams. I had to use 320x200
and 160x100
resolution. The frame rates were unusable for my needs. Around 3 - 5
fps irc.

Such resolutions are useless, especially for stereo vision. I think either you handle two streams on DSP or use something more powerful.

2010/10/10 djlewis <djlewis@tcworks.net>

I will use C4.
3-5 fps is enough for me. But (for the future work) is is possible to
get real time stereo video? I don't need any image processing
functions, I just need capture video signal and transfer it over WiFi.

What do you think about ts7800? Is it powerful enough?

ts7800 - Do you think 500Mhz ARM9 CPU can be better that 720MHz Cortex-A8?? I don’t think so.

May be you try your application at ATOM based board like ION? They are cheaper than Beagleboard and the performance is better. Moreover ION platform can be with wifi integrated and it would be PCI based, not USB. I suppose USB bus is too slow at OMAP3, so the more devices on the bus the slower bandwidth is for each.

2010/10/11 hudvin <hudvin@gmail.com>

hudvin <hudvin@gmail.com> [2010-10-10 16:16:22]:

What do you think about ts7800? Is it powerful enough?

Look at the CPU it uses, I think it's not as powerfull as the OMAP3 in Beagle.
Maybe, that Pandaboard would be powerfull enough to handle two web cams. Don't
know if it could handle the stereo vision application. There's some GSOC
project for DSP optimized OpenCV, but didn't tried it yet.

-- ynezz

Petr �tetiar wrote:

hudvin<hudvin@gmail.com> [2010-10-10 16:16:22]:

What do you think about ts7800? Is it powerful enough?

Look at the CPU it uses, I think it's not as powerfull as the OMAP3 in Beagle.
Maybe, that Pandaboard would be powerfull enough to handle two web cams. Don't

I doubt that is it 720Mhz vs 1GHz that will change the fact that the system
struggles to support 2x 320x200 webcams. More likely the bottleneck is inside
the linux USB and/or V4L2 layers and as far as USB is concerned, its the
same controllers on OMAP3 and OMAP4.

Vladimir Pantelic <vladoman@gmail.com> [2010-10-11 12:49:36]:

Petr �tetiar wrote:

hudvin<hudvin@gmail.com> [2010-10-10 16:16:22]:

What do you think about ts7800? Is it powerful enough?

Look at the CPU it uses, I think it's not as powerfull as the OMAP3 in Beagle.
Maybe, that Pandaboard would be powerfull enough to handle two web cams. Don't

I doubt that is it 720Mhz vs 1GHz that will change the fact that the system
struggles to support 2x 320x200 webcams. More likely the bottleneck is inside
the linux USB and/or V4L2 layers and as far as USB is concerned, its the
same controllers on OMAP3 and OMAP4.

Well, even if you can grab the video in such or even higher resolution, you
wouldn't have enough computing power left to do the stereo vision stuff in
real time (I'm talking about the stock OpenCV).

-- ynezz

Hudvin, if you can tolerate slow frames then it might work for you.
Keep in mind as was mentioned of the usb bottleneck. Two webcams
and wifi on usb as a minimum will reduce usb throughput.
   I should also mention that my results were with a gui running in
Angstrom. With gpm disabled using ffmpeg I got better results as
in lower overall cpu usage. I did not stream video, just displayed
locally on my C2. If you can afford the pieces then go ahead
and experiment.
   I have used OpenCV on my C2 and with one cam it does work at
640x480
but at about 7 to 10 fps in gpm. I did make an attempt to stream video
but was unsuccessful. I never got a working stream. It may work better
now as I have not attempted since Angstrom 2.6.28.
   In summary i remind the list that while two webcams might work well
for their needs
it was not adequate for mine. I am not a sharp programmer to be able
to optimize
the pieces that should already be optimized (excluding OpenCV as it is
far
from optimized).

Don

Maybe...
Just found http://www.fit-pc.com/web/fit-pc2/fit-pc2i-specifications/

I know nothing about DSP functions supported but DSP still exists at BB and why not to utilize it? I think it can process at least one video stream.

2010/10/11 djlewis <djlewis@tcworks.net>

I know nothing about DSP functions supported but DSP still exists at BB and
why not to utilize it? I think it can process at least one video stream.

Maybe the following information would be helpful to estimate what is
possible. Recently I've manage to capture video from two usb cameras
on C4 (320x240 and 160x120 each with 30fps), mix them together (kind
of PiP), compress with h264 and stream over the network (usb wlan
stick). It was accomplished with gstreamer and corresponding
DSP-enabled codec from TI (TIVidenc1). The overall system load
reported by top was about 85%. I did not try it yet, but I feel like
capturing two 320x240@30fps streams should be possible and USB
bandwidth should not be a problem for this case.

Since h264 is rather complicated codec, I think it could be compared
with the complexity of 3D vision. So, as Maxim mentioned, if done on
DSP, I think there are chances that it would work for 320x240
resolution. Otherwise, you can consider just to stream two pictures
and make havy processing on another computer.

If you are interested, here you can find some example gstreamer
pipelines for similar cases (search for TIVidenc1) here:
http://www.gitorious.org/veter/veter/blobs/master/misc/car.config

Anyway ATOM requires testing for the application because I have ASUS EEE PC701 based on ATOM and it runs extremely slow!

2010/10/11 hudvin <hudvin@gmail.com>