Questions tagged [v4l2]
v4L2 is the second version of Video4Linux, a collection of device drivers and an API for supporting realtime video capture.
53 questions
38
votes
8
answers
97k
views
RasPi Camera Board and Motion
I just got my Camera Board and a Model A Raspberry Pi to use as a security camera for my house. I had been using Motion with a Logitech C170 USB camera on my Model B board and it worked great except ...
- 4,862
7
votes
2
answers
20k
views
v4l2-ctl single frame capture produces image with green ending
I have a HDMI capture card and I'm using raspbian.
I want to get one single frame with v4l2-ctl command, then convert it to something common:
Get a frame:
# v4l2-ctl --device /dev/video0 --stream-...
- 279
4
votes
3
answers
12k
views
Raspberry Pi 3 and V4L2 C++ Capture Code for JPEGs
I have a Raspberry Pi 3 with the latest Raspbian Stretch, and the Sony 8MB official camera.
I can save a good looking JPEG with the following commands:
v4l2-ctl --set-fmt-video=width=2592,height=...
- 71
4
votes
1
answer
10k
views
Error loading bc2835-v4l2 driver, Raspberry Pi and OpenCV
disclaimer: I am new to OpenCV and Raspberry Pi, although I have a fair amount of experience with linux systems in general
Here is what I am attempting to accomplish:
I am trying to use a Raspberry ...
- 71
4
votes
2
answers
4k
views
Getting kernel headers for raspberry pi 2
I'm attempting to create a virtual video device on raspberry pi 2 using v4l2loopback and prior installation of the v4l2loopback on their website in the Dependencies section they say that the kernel ...
- 141
3
votes
2
answers
6k
views
Setting camera module to /dev/video0 to scan QR Codes using zbar
I'm trying to use the library zbar to scan qr codes using Raspberry pi's camera module. I've connected and tested the camera, but I don't know how to access that from the library because it isn't on /...
- 31
3
votes
1
answer
7k
views
How do you set hardware video encoder options with V4L2 M2M?
TL;DR When using ffmpeg and the h264_v4l2m2m hardware-accelerated codec, how do I set the encoder options such as the bitrate and key frame interval?
Details
I am using these commands to capture raw ...
- 1,904
3
votes
3
answers
7k
views
Hardware-encoding (h264_v4l2m2m) a MJPEG stream from a webcam
I have a 1080p webcam connected to a Raspberry Pi 4B over USB. The camera supports the following formats:
Raw : yuyv422 : YUYV 4:2:2
Compressed: mjpeg : Motion-JPEG
...
- 139
3
votes
0
answers
1k
views
Trying to use cec-compliance fails with open on /dev/cec0
I'm trying to use the hdmi cec tools that come with the latest Raspian. When I try and run cec-ctl or cec-compliance I get a fail to open /dev/cec0. The kernel modules I have from lsmod (partial):
...
- 31
2
votes
4
answers
3k
views
Adjusting keyframe rate ffmpeg Logitech C920 to YouTube Live
I'm trying to use ffmpeg to stream output from a c920 webcam to YouTube live on a Raspberry Pi.
Unfortunately, YouTube Live returns this error when I start the stream:
Please use a keyframe ...
- 41
2
votes
2
answers
5k
views
Problems using bcm2835_v4l2 module w/ ffmpeg
I've run into some problems using the native bcm2835_v4l2 module on my Raspberry Pi Zero W (running Raspbian Stretch). The module is loaded and the associated video device is visible:
$ v4l2-ctl --...
- 673
2
votes
2
answers
5k
views
Stream video from Raspberry Pi to PC using the Ethernet or USB port
I've got a v4l2loopback running on the Raspberry Pi and I can access the stream using MPlayer directly on the Raspberry Pi. However, I'd like to connect the Raspberry Pi to my Windows PC to access the ...
- 21
2
votes
0
answers
196
views
Green frames when capturing webcam
We use RPI4 for automation. One of our use-cases is to capture image frames via webcam/HDMI grabber as fast as possible and do some analytics. We use python and opencv for capturing, but it's not ...
- 21
2
votes
0
answers
809
views
Does V4L2 driver support Raw Bayer capture with HQ camera?
I was under impression that current V4L2 driver supports raw capture, but:
pi@raspberrypi:~ $ v4l2-ctl --list-formats
ioctl: VIDIOC_ENUM_FMT
Type: Video Capture
[0]: 'YU12' (Planar YUV 4:2:0)
...
- 121
2
votes
0
answers
497
views
Jessie: v4l2 streaming works with RPi 1B+, but not with 2B or 3B
I just recently upgraded my series of Pi's (1B+, 2B, 3B) to Raspbian Jessie Lite. Now, when I try to setup a stream with my Pi NoIR Camera as I did in Wheezy,
sudo modprobe bcm2835-v4l2
cvlc v4l2:///...
- 21
1
vote
1
answer
13k
views
What is the correct method for streaming video from the camera module to date? [closed]
I just started experimenting with a new Raspberry Pi 3 Model B with the latest Raspbian installed. I was looking for the best way to stream from the camera module and I have found different answers, ...
- 113
1
vote
1
answer
7k
views
RaspberryPi Camera - bcm2835-v4l2 kernel module source
I want to make some optimizations on camera kernel module so it can work better with a camera multiplexer module. There are 4 camera multiplexed by GPIO pins and some hardware.
I have cloned the v4l-...
- 113
1
vote
2
answers
8k
views
ffmpeg video file with v4l2 driver
I want to save a video file from the raspberry camera, by using the v4l2 driver and ffmpeg.
v4l2-ctl is able to capture the video, though ffmpeg is not.
When i run the command: ffmpeg -f video4linux2 -...
- 113
1
vote
1
answer
15k
views
Setting up RTSP using v4l2
Around one year ago I built some Raspberry pi streaming device fitting on a model train. Being unhappy with the setup process on how to receive the stream on windows (using MPlayer), I decided to use ...
1
vote
1
answer
3k
views
Trouble using UV4L raspidisp
I'm having trouble using the UV4L raspidisp device driver from linux-projects. This is supposed to provide a V4L2 compliant device that provides the output from the Raspberry Pi's HDMI output at /dev/...
- 2,702
1
vote
2
answers
3k
views
How to set the camera sensor mode with V4L2
I'm referring to the modes listed here.
When capturing video with raspivid, the -md option allows overriding the default mode selection heuristic.
I need to find out how to achieve the same when ...
- 76
1
vote
2
answers
394
views
Raspbian Jessie and OpenCV 2.4.9 "get_buffer() failed (-12 (nil))" error
I upgraded my RPI2 to use Raspbian Jessie. (NOOBS 1.9.0)
I also installed OpenCV 2.4.9.1 package. (It is the default package from apt-get install)
Now, I have a problem while recording video with ...
- 586
1
vote
1
answer
3k
views
Gstreamer and Raspberry Pi 5
For a couple of days I'm trying to make the gstreamer work on my new RPI5
PRETTY_NAME="Debian GNU/Linux 12 (bookworm)"
NAME="Debian GNU/Linux"
VERSION_ID="12"
VERSION=&...
- 11
1
vote
1
answer
2k
views
UV4L and v4l2rtspserver
I am trying to stream with uv4l over v4l2rtspserver
This is what I do:
Start /dev/video0
$ uv4l -nopreview --auto-video_nr --driver raspicam --encoding h264
[core] Trying to loading driver '...
- 33
1
vote
1
answer
9k
views
How to increase usb webcam fps?
To record video from my USB webcam I use ffmpeg with v4l2 driver (command below).
ffmpeg -f v4l2 -r 30 -s 640x480 -an -sn -i /dev/video0 -f avi temp
Unfortunately fps is too low for 640x480 (around ...
1
vote
1
answer
4k
views
Raspbian Stretch C920 webcam driver LED control regression?
In a previous Stack Overflow post (April 16th 2018), Raspberry Pi : use VLC to stream webcam : Logitech C920 [H264 Video without transcoding + Audio + LED control], I described how to use the Pi + ...
- 121
1
vote
1
answer
7k
views
How do I install v4l2loopback on raspbian Jessie
Normally I get v4l2loopback by simply
git clone https://github.com/umlaeute/v4l2loopback
cd v4l2loopback
make && sudo make install
sudo modprobe v4l2loopback video_nr=10,11
and now I get:
...
- 123
1
vote
1
answer
2k
views
V4l2 video streaming on Arch with RPi2
I'm running an intentionally minimal Arch OS on my RPi2 (installed via ArchLinuxARM-rpi-2-latest.tar.gz dated 2015-08-14), and I'm trying to have it stream video from the camera. I followed the camera ...
- 121
1
vote
1
answer
203
views
ffmpeg consume 252% of raspberrypi CPU
I am using raspberry pi-4 8GB to take input from a video device /dev/video0 and output it over a network rtp://192.168.10.10:6001 I am using following ffmpeg command ffmpeg -f v4l2 -i /dev/video0 -c:v ...
- 23
1
vote
0
answers
73
views
IR-Keytable support for the variable frequency & modulation
I am working on the RPI-CM4 with the ir-keytable library.
I am using the TSMP97000 sensor to read the modulated data from the IR transmitter(Remote).
it-keytable library is working successfully with ...
- 65
1
vote
0
answers
217
views
Picamera on Ubuntu 18.04 64-bit
Is there any way to get picamera to work on Ubuntu 18.04 64-bit. I have tried:
Compiling a non-official version of userland for 64-bit and it compiled, but the camera does not work
I have tried using ...
- 11
1
vote
1
answer
170
views
HQ Camera V4L2 - bad set of scene mode causes camera controls to become unresponsive
I have been playing with these cameras for some time using opencv/raspicam to control the camera. The raspicam/opencv interface allows setting the gain, this is dubious because there is no manual set ...
- 11
1
vote
0
answers
762
views
HQ Camera crashes OpenCV application on Raspberry Pi 4
I have been developing an object tracking application with OpenCV 4.3.0 and C++.
I am using an actively cooled Raspberry Pi 4 2GB RAM and the HQ camera module.
Twice when I ran the program, I ...
- 11
1
vote
0
answers
387
views
USB camera pipe error after a while
We have RPi3B+ with Raspbian Lite installed, 2.5A power supply. We need to connect a specific USB camera (LEPTON PureThermal 2) and display its image. The connection with the camera works, it gives ...
- 241
1
vote
0
answers
591
views
Streaming HLS from a video4linux2 virtual video device
I'm trying to accomplish a few things at the same time with the raspberry pi camera;
create an HLS live stream
take regular interval jpg snapshots and save them to disk
irregularly record short ...
1
vote
0
answers
2k
views
/dev/video0 not created
I am having trouble getting a USB Camera to work with a Raspberry Pi 3 Model B. I cannot get /dev/video0 to be created. I have run sudo modprobe bcm2835-v4l2 and I can see bcm2835-v4l2 when I run ...
- 31
1
vote
0
answers
765
views
Multiple webcams - cannot open in openCV & corrupted image
I've connected four USB webcams via well powered USB hub to RasPi2. I want to use them in openCV. So I setup a simple program, where I opened the cameras using cvCaptureFromCAM, captured a cv::Mat and ...
- 111
1
vote
1
answer
2k
views
Tiny picture using opencv2 and v4l2 driver
I'm using opencv2 and V4L2 driver on my pi and have managed to get a tiny picture out of the Raspberry Pi Camera Module with the following script:
#!/usr/bin/env python
import cv2
camera_port = 0
#...
- 1,121
1
vote
0
answers
519
views
avconv version 9.14 streaming video (using UV4L driver RaspiCam) and video (using ALSA) to ustream, no audio
I'm using avconv to read from /dev/video0 (which is attached to my RPi camera via UV4L) and also reading audio from my microphone using ALSA and stream it live on ustream.tv. It works just fine to ...
- 529
0
votes
1
answer
481
views
How can I use older versions of raspbian on RPi 2 B?
By what I gather from various sources, I realize that the Rpi2 Model B does not support older versions of Raspbian. I wanted to make sure there is no work around for this.
I am trying to install the ...
- 103
0
votes
1
answer
1k
views
Configuring camera with uv4l
I am using a USB camera and uv4l to stream the video to another machine. This is how I invoke uv4l: uv4l --driver uvc --device-id [bus:id] --config-file /etc/uv4l/uv4l-uvc.conf
I want to configure ...
0
votes
1
answer
3k
views
fswebcam: Unable to find a compatible palette format
I am unable to use my webcam. Running fswebcam out.png, I get the error:
Unable to find a compatible palette format.
What would be the origin of the error and how to fix it?
It can be a missing ...
- 133
0
votes
1
answer
4k
views
raspberry camera module feed is slow with Opencv using v4l2
i am trying to use Opencv to video capture from the raspi cam to do some operation on it, the problem is i am using v4l2 to capture the video and it is so slow (10 sec delay and 2 fps).
what i have ...
0
votes
0
answers
67
views
Lepton 3.5 thermal camera is too bright and impossible to recognize object
i'm trying to display Lepton 3.5 thermal camera which is uvc on Raspberry pi 5.
It can be displayed well using opencv but i need the maximum temperature of frame so this code is what i'm using.
The ...
0
votes
0
answers
65
views
poorer quality and jagged lines issue when rotating camera
I am capturing video from my raspberry pi camera using v4l2rtspserver, but I need the image to be rotated 90 degrees. Rotating it makes the image appear to have less resolution and there is an ...
- 101
0
votes
0
answers
422
views
Random disconnection of an USB Camera with Raspberry Pi 4
I've got a Raspberry Pi 4 with an USB2.0 camera connected through a slip ring. When I boot, there's no problem at all, but sometimes the Raspberry is unable to detect the camera while streaming (I'm ...
0
votes
0
answers
110
views
v4l-utils Based IR remote control
After spending a lot of time searching how LIRC works on the raspberry pi.
Found that LIRC is deprecated & will be replaced by the v4l-utils.
I would like to know,
Is there any library(git hub ...
- 65
0
votes
1
answer
511
views
v4l2src zooms when I change resolution
I have a camera module v2, which supports 1080p@30.
Following this answer, I am streaming it with gstreamer using:
gst-launch-1.0 -e v4l2src do-timestamp=true ! video/x-h264,width=640,height=480,...
- 731
0
votes
0
answers
431
views
Trying to interface OmniVision OV4689 with Raspberry Pi
I need to capture pictures on a Raspberry Pi (I'm using a Compute Module 3+) using a camera based on the OmniVision OV4689 image sensor.
The datasheet for this image sensor can be found here https://...
- 153
0
votes
0
answers
812
views
raspicam TCP video streaming over ssh - almost there.... but need help
I am trying to pipe raspivid over ssh to my main computer, and then via gstreamer send the stream to a dummy video device (thanks to V4l2loopback)
environment :
v4l2loopback version: 0.12.0
kernel ...
