Safe video switch using ADV7180 and i.MX6Q Automotive Board

[#1]

i.MX6Q Automotive board has one ADV7180 analog video decoder with 2 video inputs. By default, only input 1 is used (connector J42).

To connect 2 analog video sources and switch the display between them, the following changes are needed:

1 - Create a new IOCTL on V4L2_capture and ADV7180 device drivers to receive the information from user space application on what input will be selected.

2 - In this new IOCTL, use the "Fast Switch Script" for ADV7180 described at Analog Devices site: ADV7180 Fast Switch Script | EngineerZone 

3 - Create a user space application to call the IOCTL mentioned on step 1.

See attached:

1 - 0001-ADV7180-Adding-input-switch-IOCTL.patch.zip - Patch to be applied on NXP kernel 4.1.15_1.0.0_ga

2 - example2.c.zip - Source code example of user space application. It changes the video input in each 2 seconds. (See it working on attached video)

3 - example2.zip - User space application executable file 

4 - Makefile.zip - Makefile of user space application to be used as example

5 - adv7180_switch.mp4 - Video showing the application

In the application, VIDIOC_S_CHIP_INPUT IOCTL is called to change the input:

int input = 0;

if (ioctl(fd_capture_v4l, VIDIOC_S_CHIP_INPUT, &input) < 0) {
 printf("VIDIOC_S_CHIP_INPUT failed\n");
 return TFAIL;
 }‍‍‍‍‍‍‍‍‍‍‍‍

This IOCTL calls the ADV7180 Fast Switch Script, added on ADV7180 driver (see attached patch).

[jiache]

The files don't exit, they may have been detected.

How can i get them?

[rogerio_silva]

Hi karinavalencia‌, ebiz_ws_prod‌,

Do you know where the attached files were moved to? I don't have them anymore.

Best regards,

Rogerio

[karina_valencia]

rogeriopimentel‌,

Fixed.

[jiache]

karinavalencia       ‌rogeriopimentel‌

Thank you very much. This will be very useful in my project.

[wanbenzhou]

I patch the my file according your patch files, but difference with yours.

Could you share your adv7180.c file?  I will make a compare.  

And share your adv7180' connect  circuit , mybe I have some error with it.  

[rogerio_silva]

Hi wanbenzhou‌,

Sorry, I don't have this source code anymore. I used the 4.1.15_1.0.0_ga branch. Please, check if the branch you're applying the patch is the same.

About the HW, I used the i.MX6Q Automotive board with its base board. Do you have their schematics?

Best regards,

Rogerio

[wanbenzhou]

Thanks for your reply.

And  what's the step to switching channel?

1.  I switch the channel during  play  /dev/video0(gst-launch-1.0 imxv4l2src device=/dev/video0 ! autovideosink) success,

but sometimes, the display scroll down for a while,  such as waite a synchronize signal.

2.  If  I operate following step the screen is well. (stop play  -> switch channel  -> start play)

The result is looks like your demo video.  

Is it the right way?