I think you both may be missing the point. Whether I'm using USB, Ethernet, etc., the question is whether or not the BBB has enough processing power to run opencv on multiple 720p+ resolution streams simultaneously, whether it's two, three, or four at once.
Sure, from a bandwidth perspective you could probably run 4 IP cameras that output H.264 at the same time while also writing to a NAS over the same Ethernet line, but that's a moot point if the BBB can't actually process all that data fast enough. If the BBB can only handle running opencv on one HD camera at a time, then I'm better off just using an RPi2 where I can at least do that with a CSI2 camera for $60 all-in. Thanks for your input. Does anybody else know more specifics about the processing power side of the equation? On Feb 23, 2015 2:24 AM, "William Hermans" <[email protected]> wrote: > I think you missed my point. You *could* use ethernet as well as USB . . . > > On Sun, Feb 22, 2015 at 11:14 PM, Yiling Cao <[email protected]> wrote: > >> proper IP camera/ mobile phone camera dont use USB, they use MIPI or CSI2 >> to interface with MPU. >> >> USB webcam is just for some hobby/demo use. >> >> On Mon, Feb 23, 2015 at 1:23 PM, William Hermans <[email protected]> >> wrote: >> >>> id imagije if you used IP cameras, You could do a couple more. The BBB's >>> Ethernet port is as fast as fast Ethernet gets to theoretical. >>> >>> On Sun, Feb 22, 2015 at 6:00 PM, Alvaro Garcia <[email protected]> >>> wrote: >>> >>>> The max framerate you will get is 15 fps, no matter about USB speed. It >>>> is because of DMA problem or something. I tried several cameras and could >>>> get more than 15 fps (trying yuv, mjpeg, x264...) >>>> >>>> 2015-02-23 1:19 GMT+01:00 Alex de Geofroy <[email protected]>: >>>> >>>>> Thanks Robert, >>>>> >>>>> As a side note, thank you for all the help you provide people here and >>>>> elsewhere. I haven't been very active in this group, but I've been >>>>> subscribing and reading for a while. I guess the phrase "Long time >>>>> listener, first time caller" would be appropriate. >>>>> >>>>> Anyway, USB 2.0 will transfer at 480 Mbps (in the best case) which is >>>>> twice the bandwidth I'd need to run four 1080p30 cameras streaming MJPEG >>>>> at >>>>> approximately 60 Mbps, or roughly four times the bandwidth I'd need for >>>>> 720p30. >>>>> >>>>> So let's assume that we won't have a bottleneck on the USB, and I'll >>>>> save the videos to a NAS over Ethernet (USB & Ethernet are not shared, >>>>> right?) so we won't have a bandwidth issue there either. If this is true, >>>>> would the BBB have the horsepower to run motion detection on all four >>>>> streams and output to a NAS reliably? If not four cameras, how about 3, or >>>>> 2? >>>>> >>>>> I understand that this is a pretty specific case and I might just have >>>>> to try it out to see what it can handle, I'm just trying to get a feel for >>>>> whether or not it's even worth trying with a BBB, or if I should look for >>>>> a >>>>> higher-end board and cough up the extra cash. >>>>> >>>>> Thanks again! >>>>> >>>>> On Sun, Feb 22, 2015 at 6:56 PM, Robert Nelson < >>>>> [email protected]> wrote: >>>>> >>>>>> On Sun, Feb 22, 2015 at 5:48 PM, Alex DG <[email protected]> >>>>>> wrote: >>>>>> > I've been playing around with my BBB for a couple months now and I >>>>>> love it. >>>>>> > I've currently got it set up streaming video to my website 24/7. >>>>>> > >>>>>> > I'm now wondering how many USB cameras I could reasonably expect to >>>>>> use on >>>>>> > this thing at one time, because I want to set up a sort of improved >>>>>> IP >>>>>> > camera system. Essentially I want to create a networked array of HD >>>>>> cameras, >>>>>> > so I'm trying to decide which SBC would be able to reliably record >>>>>> 720p or >>>>>> > 1080p video from as many cameras as possible. The cameras need to >>>>>> run 24/7, >>>>>> > detect motion, perform some CV tasks (using opencv, presumably), >>>>>> and save >>>>>> > the resulting clips to a NAS, or even just to a USB hard drive. >>>>>> > >>>>>> > So let's say I want to set up an array of 720p30 cameras and record >>>>>> and >>>>>> > process video from them. Using a USB hub, would the BBB handle 2, >>>>>> 3, or even >>>>>> > 4 cameras? What if the frame rate was 60 fps? Or what about 2, 3, >>>>>> or 4 >>>>>> > 1080p30 cameras? >>>>>> > >>>>>> > I'm just trying to get a feel for how capable the BBB is, or if I >>>>>> should >>>>>> > look toward a different, more powerful SBC. >>>>>> > >>>>>> > Thanks in advance for any advice you can offer! >>>>>> >>>>>> Remember, usb is a shared resource. With only one port on the BBB, >>>>>> depending on how much bandwidth the first camera takes will let you >>>>>> know how many you can have plugged in. >>>>>> >>>>>> Regards, >>>>>> >>>>>> -- >>>>>> Robert Nelson >>>>>> http://www.rcn-ee.com/ >>>>>> >>>>>> -- >>>>>> For more options, visit http://beagleboard.org/discuss >>>>>> --- >>>>>> You received this message because you are subscribed to a topic in >>>>>> the Google Groups "BeagleBoard" group. >>>>>> To unsubscribe from this topic, visit >>>>>> https://groups.google.com/d/topic/beagleboard/a3-AuBq9eyo/unsubscribe >>>>>> . >>>>>> To unsubscribe from this group and all its topics, send an email to >>>>>> [email protected]. >>>>>> For more options, visit https://groups.google.com/d/optout. >>>>>> >>>>> >>>>> -- >>>>> For more options, visit http://beagleboard.org/discuss >>>>> --- >>>>> You received this message because you are subscribed to the Google >>>>> Groups "BeagleBoard" group. >>>>> To unsubscribe from this group and stop receiving emails from it, send >>>>> an email to [email protected]. >>>>> For more options, visit https://groups.google.com/d/optout. >>>>> >>>> >>>> -- >>>> For more options, visit http://beagleboard.org/discuss >>>> --- >>>> You received this message because you are subscribed to the Google >>>> Groups "BeagleBoard" group. >>>> To unsubscribe from this group and stop receiving emails from it, send >>>> an email to [email protected]. >>>> For more options, visit https://groups.google.com/d/optout. >>>> >>> >>> -- >>> For more options, visit http://beagleboard.org/discuss >>> --- >>> You received this message because you are subscribed to the Google >>> Groups "BeagleBoard" group. >>> To unsubscribe from this group and stop receiving emails from it, send >>> an email to [email protected]. >>> For more options, visit https://groups.google.com/d/optout. >>> >> >> -- >> For more options, visit http://beagleboard.org/discuss >> --- >> You received this message because you are subscribed to the Google Groups >> "BeagleBoard" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to [email protected]. >> For more options, visit https://groups.google.com/d/optout. >> > > -- > For more options, visit http://beagleboard.org/discuss > --- > You received this message because you are subscribed to a topic in the > Google Groups "BeagleBoard" group. > To unsubscribe from this topic, visit > https://groups.google.com/d/topic/beagleboard/a3-AuBq9eyo/unsubscribe. > To unsubscribe from this group and all its topics, send an email to > [email protected]. > For more options, visit https://groups.google.com/d/optout. > -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. 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