A. I have a general understanding question about the "still pin" or "snapshot" functionality on some web cameras: how does this work ? It must be one of the following possibilities:
The camera is on and video is streaming to the host. When the snap button is pressed, a signal is sent to the host's camera driver (/dev/input/event0 on linux), the driver extracts a frame from the stream, and sends it up in the stack.
The camera is on and video is streaming (or not) to the host. When the snap button is pressed, the on board firmware puts aside the current frame, and tells the host a new "still" is available.
B. I have 4 usb cameras attached on a R-Pi (single usb host). All cameras have a still pin. I don't care about the video, no need for streaming, I want to take 4 simultaneous photos. My idea is to trigger all 4 cams to capture a frame using the still pin. How can I capture those 4 images without streaming video (bandwidth issues) ?
Note: I have already experimented a lot and I am capable of capturing a frame from a video stream. My cameras are unknown brands but exposes "video capture" as device caps. When using AMCap on windows, the snap button triggers a snapshot.
Thanks for any help.
Related
I am trying to take photos while the camera is connected to the computer. As soon as the camera is connected to to PC the camera changes it's mode to busy. I would like trigger the camera to take picture while it is connected to the computer.
You can use the EdsSendStatusCommand function with kEdsCameraStatusCommand _UIUnLock to use the camera manually while plugged in. Note that some commands issued with the Canon SDK may lock the camera UI again.
I just found a great bluetooth keyboard by Brydge for the Pixel Slate and am wondering if current ChromeOs devices can manually transfer from "tablet" to "desktop" mode when you attach a bluetooth keyboard?
It seems like this is feasible by enabling a setting in developer mode. Thanks to #Skawtnyc's response on Reddit!
You can switch back and forth on the fly. Enable chrome://flags/#ash-debug-shortcuts and then you can use CTRL+SHIFT+ALT+T to switch back and forth between desktop and tablet mode.
If you connect a mouse it will automatically switch to desktop mode, but using this method you can still switch back and forth.
#Skawtnyc also points out a bug to watch out for when using an external display such as a monitor.
Keep in mind that when connected to a dock with an external display, this setup can trigger a crash/restart error. The cause is the virtual keyboard. Anything that causes the virtual keyboard to appear on screen will trigger it. The workaround is to go into Accessibility settings and turn off the on-screen keyboard. You don't need it anyway when using a physical keyboard.
Could I send an image or video from Arduino IDE to Touch Designer software?
Could I use the pictures saved with the CMOS camera for example?
Thanks,
Giuseppe
You can send images via bluetooth, wifi or serial, but the speed of taking the picture and sending over wont be that fast.
You are better of with a gopro connected via wifi or Canon via usb cable. Forget Arduino if you need a live feed.
WebRtc sample
If I press call, allow/deny menu is shown in the upper screen. When I press allow, Chrome starts displaying red circle in the header which signals that microphone is active. All other sounds in others Chromes tabs are muted (for example youtube video).
When I press hang, red circle does not dissapears, youtube video in second tab is still muted. I have to press F5 to restore state which was before call.
Is there any PeerConnection to stop the call and stop mic recording ?
Yes, the reason the "red light" is still on is that the media tracks in the mediaStream object (called localstream on that particular page) gathered through getusermedia is still playing/active.
To close a media stream and thus release any hold on the local media inputs simply call localstream.stop() that will end the stream and stop accessing the local media input. This will stop all associated media tracks.
You can also do this by calling stop() on the individual media tracks(grabbed from getVideoTracks or getAudioTracks from the mediaStream).
As for other audio being turned down in other pages/apps. Here is the crbug handling that issue.
Side Note: if the media is being pushed through a peerConnection, then you will probably have to renegotiate the connection due to the mediaStream changing.
I'm working with a Sony DSC-QX100 camera via Sony's Remote Camera api, specifically for use on a Windows 8 tablet (basically replacing the built-in camera of the tablet with this unit). I'm able to consume the camera's LiveView (streaming) and LiveShot (take a picture and retrieve the image from url) features triggered from my application.
My question is whether or not the Remote Camera api exposes any functionality to access pictures stored on the camera's SD card (when it is available). Bottom line, my user may choose to take the picture directly with the camera unit (manually, instead of remotely via my application on the tablet) and I've not yet found the method by which to retrieve this picture from the camera (other than transferring the SD card from camera to pc). Anyone tried this or seen something in the API documentation that I'm missing?
Current Camera Remote API does not provide direct access to SD card.
All available APIs are documented.