IMX CSI

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VAR-SOM-MX7 - Camera

1 Testing our MIPI cameras

1.1 Camera probe

Make sure the camera is connected, and boot the board.
Then, run the below command to verify the camera was detected successfully:

# v4l2-ctl --list-devices

This should output below

i.MX6S_CSI (platform:30710000.csi):
        /dev/video1

pxp (pxp_v4l2_out):
        /dev/video0

In the output seen above, "i.MX6S_CSI" is the camera, and "pxp" is the i.MX Pixel Processing Pipeline.

1.2 i.MX platform specific gstreamer plugins

Run below command to verify you have the i.MX7 platform specific gstreamer plugins installed on your system:

# gst-inspect-1.0  | grep "imx"
imxpxp:  imxpxpvideotransform: Freescale PxP video transform
imxpxp:  imxpxpvideosink: Freescale PxP video sink
imxv4l2videosrc:  imxv4l2videosrc: V4L2 CSI Video Source
imxaudio:  imxmp3audioenc: Freescale i.MX MP3 encoder
imxaudio:  imxuniaudiodec: Freescale i.MX uniaudio decoder

1.3 Gstreamer example 1: Testing Camera Loopback / Camera preview on the display

The below pipelines are suitable for the fslc based Yocto releases for the VAR-SOM-MX7 (Yocto Morty and newer).

  • For 640x480@30fps:
# gst-launch-1.0 imxv4l2videosrc device=/dev/video1  imx-capture-mode=0 ! imxpxpvideosink
  • For 720x480@30fps:
# gst-launch-1.0 imxv4l2videosrc device=/dev/video1  imx-capture-mode=1 ! imxpxpvideosink
  • For 1280x720@30fps :
# gst-launch-1.0 imxv4l2videosrc device=/dev/video1  imx-capture-mode=2 ! imxpxpvideosink
  • For 1920x1080@30fps:
# gst-launch-1.0 imxv4l2videosrc device=/dev/video1  imx-capture-mode=3 ! imxpxpvideosink
  • For 2592x1944@15fps:
# gst-launch-1.0 imxv4l2videosrc device=/dev/video1  imx-capture-mode=4 ! imxpxpvideosink

1.4 Gstreamer example 2: Taking a JPEG snapshot from the camera

To capture and encode a JPEG snapshot from the camera, run one of the below pipelines depending on the wanted resolution:

  • For 640x480:
# gst-launch-1.0 imxv4l2videosrc device=/dev/video1  imx-capture-mode=0 num-buffers=1 ! 'video/x-raw,format=UYVY' ! jpegenc ! filesink location=/tmp/test.jpg
  • For 720x480:
# gst-launch-1.0 imxv4l2videosrc device=/dev/video1  imx-capture-mode=1 num-buffers=1 ! 'video/x-raw,format=UYVY' ! jpegenc ! filesink location=/tmp/test.jpg
  • For 1280x720:
# gst-launch-1.0 imxv4l2videosrc device=/dev/video1  imx-capture-mode=2 num-buffers=1 ! 'video/x-raw,format=UYVY' ! jpegenc ! filesink location=/tmp/test.jpg
  • For 1920x1080:
# gst-launch-1.0 imxv4l2videosrc device=/dev/video1  imx-capture-mode=3 num-buffers=1 ! 'video/x-raw,format=UYVY' ! jpegenc ! filesink location=/tmp/test.jpg
  • For 2592x1944:
# gst-launch-1.0 imxv4l2videosrc device=/dev/video1  imx-capture-mode=4 num-buffers=1 ! 'video/x-raw,format=UYVY' ! jpegenc ! filesink location=/tmp/test.jpg

2 References