Camera¶
Testing MIPI-CSI2 and parallel CSI cameras¶
Make sure you have the camera(s) connected to the board before booting it and running any of the pipelines below . The i.MX family of SOCs uses gstreamer as a multimedia framework. Please refer to https://gstreamer.freedesktop.org/
Camera Probe¶
Run the following command to list the detected camera devices:
This should produce the following output:
v4l2-ctl --list-devices
vpu B0 (platform:):
/dev/video12
/dev/video13
mxc-isi (platform:58100000.isi.0):
/dev/video0
/dev/video2
mxc-isi (platform:58140000.isi.4):
/dev/video1
mxc-jpeg decoder (platform:58400000.jpegdec):
/dev/video3
mxc-jpeg decoder (platform:58450000.jpegenc):
/dev/video4
There are two cameras accessible as /dev/video0 and /dev/video1. The first one is a MIPI-CSI2 camera attached to the VAR-EXT-CB8 expansion board, and the second one is a parallel CSI camera attached to the VCAM-5640P expansion board.
Testing Camera Preview on Display¶
In the examples below /dev/video1 can be used instead of /dev/video0 on boards with 2 cameras.
- 480p (640x480):
gst-launch-1.0 v4l2src device=/dev/video0 ! video/x-raw,width=640,height=480 ! autovideosink sync=false
- NTSC (720x480):
gst-launch-1.0 v4l2src device=/dev/video0 ! video/x-raw,width=720,height=480 ! autovideosink sync=false
- 720p (1280x720):
gst-launch-1.0 v4l2src device=/dev/video0 ! video/x-raw,width=1280,height=720 ! autovideosink sync=false
- 1080p (1920x1080):
gst-launch-1.0 v4l2src device=/dev/video0 ! video/x-raw,width=1920,height=1080 ! autovideosink sync=false
- QSXGA (2592x1944):
gst-launch-1.0 v4l2src device=/dev/video0 ! video/x-raw,width=2592,height=1944 ! autovideosink sync=false
Note: The parallel camera maximal frame rate at the 1920x1080 and 2592x1944 resolutions is 7.5fps
Testing Camera JPEG Snapshot¶
To capture a JPEG snapshot run one of the pipelines below, depending upon the required picture resolution. In the examples below /dev/video1 can be used instead of /dev/video0 on boards with 2 cameras.
- 480p (640x480):
gst-launch-1.0 v4l2src device=/dev/video0 num-buffers=1 ! video/x-raw,width=640,height=480 ! v4l2jpegenc ! filesink location=/tmp/test.jpg
- NTSC (720x480):
gst-launch-1.0 v4l2src device=/dev/video0 num-buffers=1 ! video/x-raw,width=720,height=480 ! v4l2jpegenc ! filesink location=/tmp/test.jpg
- 720p (1280x720):
gst-launch-1.0 v4l2src device=/dev/video0 num-buffers=1 ! video/x-raw,width=1280,height=720 ! v4l2jpegenc ! filesink location=/tmp/test.jpg
- 1080p (1920x1080):
gst-launch-1.0 v4l2src device=/dev/video0 num-buffers=1 ! video/x-raw,width=1920,height=1080 ! v4l2jpegenc ! filesink location=/tmp/test.jpg
- QSXGA (2592x1944):
gst-launch-1.0 v4l2src device=/dev/video0 num-buffers=1 ! video/x-raw,width=2592,height=1944 ! v4l2jpegenc ! filesink location=/tmp/test.jpg
Using 2 cameras simultaneously¶
The following pipeline is an example of using 2 cameras simultaneously. In this example a short video stream from each camera is saved as an MJPEG-encoded AVI file.