The quad-core cortex-A7 cpu of the RPi2 has more processing power than the single core cortex-A8 of the BBB, specially if you can multi-thread your opencv tasks.
But even the RPi2 may not reach your expectations. Some opencv feature extractions are way cpu intensive, demanding more than 1s/frame on an A8. Add to that the decoding of the H264 stream. I guess only a desktop will handle multiple HD sources. Regards, Ivan On Mon, 23 Feb 2015 03:28:50 -0500 Alex de Geofroy <[email protected]> wrote: > 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. > 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.
