topic Re: getting frame data from /dev/video1 for processing and displaying, Linux on iMX6Q in i.MX Processors

getting frame data from /dev/video1 for processing and displaying, Linux on iMX6Q

jingyizhang — Wed, 05 Aug 2015 16:23:20 GMT

Hi,

I am trying to write a terminal app which init the camera and manipulate the input frame by frame on a pixel level before displaying to LCD or storing to disk.

Can anyone point me in the right direction on how to get started? I am very new to programming in Linux, any documentation or sample code would be very helpful.

I am currently running an unmodified fsl-image-qt5-x11-imx6qdlsolo image on the i.MX6Q Sabre-SD Platform board.

Re: getting frame data from /dev/video1 for processing and displaying, Linux on iMX6Q

Yuri — Thu, 06 Aug 2015 02:16:14 GMT

General information how to use V4L2 API (with examples) may be found at

http://linuxtv.org/downloads/v4l-dvb-apis/

Also, it makes sense to look at Chapter 9 [Video for Linux Two (V4L2)
Driver ] of “i.MX_6_Linux_Reference_Manual.pdf” ; in particular – section
9.5.2 (Video4Linux API test).

https://www.freescale.com/webapp/Download?colCode=L3.14.28_1.0.0_LINUX_DOCS&location=null&fpsp=1&WT_TYPE=Supporting%20Information&WT_VENDOR=FREESCALE&WT_FILE_FORMAT=gz&WT_ASSET=Documentation&fileExt=.gz&Parent_nodeId=1337637154535695831062&Parent_pageType=product

You may to look to test sources on the host Linux :

/fsl-release-bsp/tmp/work/-poky-linux-gnueabi/imx-test/

Inside each test’s directory you will find the available documentation.

Have a great day,
Yuri

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Re: getting frame data from /dev/video1 for processing and displaying, Linux on iMX6Q

BiyongSUN — Thu, 06 Aug 2015 05:00:00 GMT

Please refer to the mxc_vpu_test.out source code.

for test, here is the command

modprobe ov5640_camera_mipi
modprobe ov5642_camera
modprobe mxc_v4l2_capture

/unit_tests/mxc_vpu_test.out -E "-x 0 -o /enc.h264 -w 720 -h 480 -c 5000 -f 2"

-x <input method> input mode V4L2 with video node
0 - /dev/video0, 1 - /dev/video1, and so on

then you can play the enc.h264 with following command

/unit_tests/mxc_vpu_test.out -D "-i /enc.h264 "