topic Re: iMX6 camera preview IPU functionality in i.MX Processors

iMX6 camera preview IPU functionality

uSasha — Thu, 11 Dec 2014 09:24:45 GMT

Hello,

there is a "camera preview" function in iMX's image processing unit.

User guide explanation is very short:

37.1.2.1.6.3 Camera Preview

• Tearing artifacts can be prevented by (automatic) page-flip double buffering in

system memory

• Alternatively, the video stream from an image sensor can be sent directly to the

display buffer used for screen refresh. The significance of this option is that only a

single frame buffer is needed (and not two). This buffer may be located either in

system memory or in an external display controller.

• This option is useful, e.g., in a low frame rate, when tearing is not visible.

• When tearing must be prevented, the refresh cycle in the display can be

synchronized with the timing signals from the sensor (two refresh cycles for each

input frame): the IPU receives a VSYNC signal from the sensor and generates

from it synchronization signals for the display.

The question is: how to configure IPU to stream video directly from sensor to screen without CPU interaction?

Main idea to implement "instant start" appearence, show video from bootloader and then start linux.

igorpadykov — Thu, 11 Dec 2014 10:52:26 GMT

Hi Alex

please look at SDK example and sect.18.5 CSI preview

iMX6_Firmware_Guide.pdf (included to SDK)

Best regards

igor

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uSasha — Thu, 11 Dec 2014 13:58:45 GMT

Thanks, Igor!