To expand on this, I have a down-facing camera using the whycon ROS node on Ubuntu 16.04 Kinetic on a quad-core computer with 640x480@60fps MJPG video. I'm also using the
usb_cam node to publish the
image_raw. I've noticed that the overall CPU consumption would already be above 90% for all 4 cores whenever I try to run just these 2 nodes.
But I also want to add a secondary front-facing USB camera that will only be for streaming video to another computer. This secondary camera ideally should have a 1280x720 resolution. I tried to run both cameras at the same time, but the 1280x720 one is only at 10-12fps, which is too slow for my purposes. Additionally, it would be great if I can also have the whycon node to be using 1280x720, but I think the framerate should have a higher priority.
I realize that I can lower both resolutions to 640x480 and that should help with the framerate issue, but is that really the only way to ensure a smoother video?
I also have a single USB 3.0 port and 2 USB 2.0 ports on my computer and I have plugged in the front-facing camera into the USB 3.0 port. I've also already ran
v4l2-ctl --list-formats-ext on my cameras (they are exactly the same) and they both are only capable of 60fps up to 1920x1080.
EDIT: A follow-up question I have is if it would be better to switch to a different computer with a better processor? What I'm currently using has the Intel Cherry Trail 1.8 Ghz Quadcore.
EDIT2: @kaliatech If I run the front camera at 1280x720, I can get up to 34fps with 1 CPU core maxing out at 100% at a time and the rest at more or less 25%. If I run just the down-facing camera at 640x480, I can get up to 60fps with CPU usage around 55% for 1 core while the rest are less than 20%. If I have both the down-facing cam and the whycon node running, I still have 60fps from usb_cam but CPU usage maxes out at 100% and 70% for 2 cores. Finally, if I run all three, the down-facing cam remains the same in terms of framerate but the front-facing has around 12 fps and at least 2 cores max out with the rest at above 60%. At this point, I'm not currently transferring the videos through the network. I'm still conducting some tests on the local computer, but you would be right that it will be much worse on a slower network. I will try to use a different camera driver like
cv_camera but I think I skipped it since it seemed older than
usb_camera and even less supported
EDIT3: I tried using cv_camera but the resulting framerate seemed about the same, if not worse.