View source for Template:Linux-RK3399MIPICamera

===Using Camera on Linux (MIPI Camera OV13850 & OV4689, and webcam logitect C920)===
Hardware Setting:
The Camera module can be connected to a MIPI port:<br />
{{#switch: {{{1}}}
 | NanoPC-T4 =
[[File:T4-mipi-single-camera.jpg|frameless|500px]]<br>
 | NanoPi-M4 =
[[File:M4-mipi-single-camera.jpg|frameless|500px]]<br>
 | NanoPi-NEO4 = 
[[File:Neo4-mipi-single-camera.jpg|frameless|500px]]<br>
 | #default =
}}

<!--
M4-mipi-dual-camera.jpg
T4-mipi-dual-camera.jpg
-->

FriendlyELEC provides some scripts use to test a camera's functions. You can run it in a commandline to test picture taking and video recording. <br />
You may try update this script to the lastest version by using the following commands:
<syntaxhighlight lang="bash">
cd /tmp/
git clone https://github.com/friendlyarm/gst-camera-sh.git
sudo cp gst-camera-sh/*.sh /usr/bin/
</syntaxhighlight>

There are three scripts:<br />
gst-camera.sh: preview, photo and video of a single camera <br />
dual-camera.sh: preview two cameras <br />
stop-gst-camera.sh: stop preview<br />
<br />

====Options in "gst-camera.sh"====
::{| class="wikitable"
|-
|Options || Comment
|-
|  --index or -i || Camera's index, it can be either 0 or 1. When two cameras are connected to a board you need to specify 1 to access the second camera.
|-
|  --action or -a || Specify an action, it can be "preview" to preview, "photo" to take a picture or "video" to record video
|-
|  --output or -o || Specify an output file to save a picture when taking a picture or video file when recording video
|-
|  --verbose or -v || If it is specified as "yes" it will output the complete command when "gst-launch-1.0" is called
|-
| -x || Using the rkximagesink plugin, the preview image will be output to the X11 window for the FriendlyDesktop and Lubuntu systems
|-
|  -g || Using the glimagesink plugin, the preview image will be output to the X11 window for the FriendlyDesktop and Lubuntu systems
|-
| -k || Using the kmssink plugin, the preview image will be output directly to the screen for the FriendlyCore system
|}

The script gst-camera.sh will automatically recognize OV13850, OV4689 and C920 camera,  and then pass the appropriate parameters to gst-launch-1.0.

====Usage of gst-camera.sh====
* '''Preview'''
<syntaxhighlight lang="bash">
gst-camera.sh --action preview
</syntaxhighlight>
* '''Picture Taking'''
You can run the following command to take a picture and save it as a "1.jpg" file,
<syntaxhighlight lang="bash">
gst-camera.sh -a photo -o 1.jpg
</syntaxhighlight>

* '''Preview and Record'''
You can run the following command to record video and save your video to a "1.ts" file. Hardware encoding is activated when it is recording video.
<syntaxhighlight lang="bash">
gst-camera.sh --action video -output 1.ts
</syntaxhighlight>
<br />
* '''Show Complete Command'''
If you add the "--verbose yes" option it will show a complete gsteamer command.
<syntaxhighlight lang="bash">
gst-camera.sh --action video --output 1.ts --verbose yes
</syntaxhighlight>
Here is the complete gsteamer command you will see:
<syntaxhighlight lang="bash">
gst-launch-1.0 rkisp num-buffers=512 device=/dev/video0 io-mode=1 ! \
    video/x-raw,format=NV12,width=1280,height=720,framerate=30/1 ! \
        mpph264enc ! queue ! h264parse ! mpegtsmux ! \
        filesink location=/tmp/camera-record.ts
</syntaxhighlight>

====gst-launch-1.0 parameter description====
Preview camera on FriendlyDesktop：
<syntaxhighlight lang="bash">
gst-launch-1.0 rkisp device=/dev/video1 io-mode=4 ! video/x-raw,format=NV12,width=1280,height=720,framerate=30/1 ! rkximagesink
</syntaxhighlight>
Important parameters
::{| class="wikitable"
|-
|parameter || description
|-
| device || preview device(selfpath): /dev/video1 and /dev/video5, picture device(mainpath): /dev/video0 and /dev/video4, webcam device: /dev/video8
|-
| io-mode || 1: memory map, 4:dmabuf
|-
| rkximagesink/glimagesink/kmssink || rkximagesink for FriendlyDesktop, kmssink for FriendlyCore, glimagesink for webcam on FriendlyDesktop
|}

====Access the camera in OpenCV====
MIPI camera：
<syntaxhighlight lang="python">
cv.VideoCapture('rkisp device=/dev/video1 io-mode=4 ! video/x-raw,format=NV12,width=640,height=480,framerate=30/1 ! videoconvert ! appsink', cv.CAP_GSTREAMER)
</syntaxhighlight>
USB camera：
<syntaxhighlight lang="python">
cv.VideoCapture('rkisp device=/dev/video8 io-mode=4 ! videoconvert ! video/x-raw,format=NV12,width=640,height=480,framerate=30/1 ! videoconvert ! appsink', cv.CAP_GSTREAMER)
</syntaxhighlight>
<br />
Please refer to the sample code here for details：https://github.com/friendlyarm/install-opencv-on-friendlycore/tree/rk3399/examples<br />
<br />

====Camera application tutorial: Push video stream====
Please refre this guide: [[RTMP-For-RK3399]]<br />

====Reference resource====
http://blog.iotwrt.com/media/2017/10/01/camera/
http://www.360doc.com/content/16/1019/17/496343_599664458.shtml