pyrav4l2 - Pythonic, Really Awesome V4L2 utility

Copyright (c) 2022 Antmicro

pyrav4l2 is a library that lets you easily control V4L2 devices inside python scripts. It provides a high level API for controlling camera parameters and streaming frames.

Installation

pip install git+https://github.com/antmicro/pyrav4l2.git

Examples

Creating device

You can create a device instance using the path of the V4L2 device:

from pyrav4l2 import Device

dev = Device("/dev/video0")

or by using its ID number:

from pyrav4l2 import Device

dev = Device.with_id(0)

Getting information about the device

You can easily get device and driver names and check if the selected device supports video capturing

from pyrav4l2 import Device

dev = Device("/dev/video0")
print(f"Device name: {dev.device_name}")
print(f"Driver name: {dev.driver_name}")
if dev.is_video_capture_capable:
    print(f"Device supports video capturing")
else:
    print(f"Device does not support video capturing")

Getting information about currently used color format and frame size

This example shows you how to check what color format and frame size is currently used by the device

from pyrav4l2 import Device

dev = Device("/dev/video0")
color_format, frame_size = dev.get_format()
print(f"Color format: {color_format}")
print(f"Frame size: {frame_size}")

Frame format enumeration and configuration

Here you can see how to get all supported color formats and frame sizes, and configure the device to use the first one of each.

from pyrav4l2 import Device

dev = Device("/dev/video0")
available_formats = dev.available_formats

for color_format in available_formats.keys():
    print(f"{color_format}:")
    for frame_size in available_formats[color_format]:
        print(f"    {frame_size}")
    print()

color_format = list(available_formats.keys())[0]
frame_size = available_formats[color_format][0]
dev.set_format(color_format, frame_size)

Device controls enumeration and configuration

This example shows how to get a list of supported controls and iterate over it. It prints the names of all controls and resets their values to the default ones.

from pyrav4l2 import Device

dev = Device("/dev/video0")
available_controls = dev.controls

for control in available_controls:
    print(control.name)
    dev.reset_control_to_default(control)

Streaming frames

Here you can see how to stream frame from the camera. The script below captures 10 frames and prints their lengths.

from pyrav4l2 import Device, Stream

dev = Device("/dev/video0")
for (i, frame) in enumerate(Stream(dev)):
    print(f"Frame {i}: {len(frame)} bytes")

    if i >= 9:
        break

License

Apache 2.0