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.
