How remove camera preview to raspberry pi
Try the nopreview option
pkill uv4l
uv4l --driver raspicam --auto-video_nr --encoding yuv420 --width 320 --height 240 --nopreview
export LD_PRELOAD=/usr/lib/uv4l/uv4lext/armv6l/libuv4lext.so
Hope that helps
Display camera preview on Raspberry Pi Android things
As commented in another issue the RPI3 camera HAL only support one target surface at a time, this apparently come from a limitation of the underlying V4L2 implementation.
The following workaround should be possible:
- for preview: use a SurfaceView as the target surface
- when taking picture: in the CaptureCallback use PixelCopy to grab the raw frame from the surface
You can find a tentative example based on the android-Camera2Basic
kotlin sample: here
Raspberry Pi - How to do other things while preview is running?
It is likely not the preview that is blocking your program, but using sleep(20)
.
Whilst the 'sleep' is occurring, nothing else can process. This causes the block you are noticing. You could fix this by removing that line, and instead binding the camera.stop_preview()
to an event (such as a key press). This could look like:
root.bind("<space>", lambda e: camera.stop_preview())
Where root
is what you define as your access to Tk()
. lambda e:
specifies an inline function expression, where e
is the event object passed.
How to make a video using raspberry pi camera without it crashing
You'll probably need to use with
to ensure the camera resources get properly released.
@app.route('/')
def index():
with PiCamera() as camera:
# camera.start_preview()
camera.start_recording('/home/pi/Desktop/play.h264')
sleep(15)
camera.stop_recording()
# camera.stop_preview()
return "OK"
If that doesn't help, there are some points about the pi camera's hardware limits here.
Capture video from camera on Raspberry Pi and filter in OpenGL before encoding
The texture conversion will work on any MMAL opaque buffer i.e. camera preview, still (up to 2000x2000 resolution), video. However, the example code only does the GL plumbing for stills preview. I think someone posted a patch on the RPI forums to make it work with RaspiVid so you might be able to use that.
Fastpath basically means not copying the buffer data to ARM memory and doing a software conversion. So, for the GL rendering it means just passing a handle to GL so the GPU driver can do this directly.
Currently, there is no support/fastpath in the drivers for feeding the OpenGL rendered buffers into the video encoder. Instead, the slow and probably impractical path is to call glReadPixels, convert the buffer to YUV and pass the converted buffer to the encoder.
A fastpath is certainly possible and I've done some work in porting this to the RPI drivers but there's some other framework required and I won't get chance to look at this until the New Year.
Related Topics
Change Parent Shell's Environment from a Subprocess
Python Library for Linux Process Management
Which Is the Preferred Way to Concatenate a String in Python
How to "Perfectly" Override a Dict
Animated Sprite from Few Images
Replace Values in a Pandas Series via Dictionary Efficiently
How to Invoke the Super Constructor in Python
From List of Integers, Get Number Closest to a Given Value
Python Dictionary: Are Keys() and Values() Always the Same Order
Docker.Errors.Dockerexception: Error While Fetching Server API Version
How to Extract Text from a PDF File
Error: Pandas Hashtable Keyerror
Capturing Repeating Subpatterns in Python Regex