topic Re: Using OCRAM as a buffer instead of SDRAM for a camera application in i.MX Processors

Using OCRAM as a buffer instead of SDRAM for a camera application

prithvirajnaren — Mon, 08 Jan 2018 16:27:34 GMT

Greetings all,

From my understanding of the camera based applications in AN12103 and AN12110 (webcam and camera to LCD/JPEG respectively), the SDRAM is just used as a buffer until the data is consumed. The data is consumed continuously to display on the LCD, compress as JPEG (needs 8 rows to start compressing if I understand correctly) or stream over USB. So a whole image isn't stored on the SDRAM, which means even the internal RAM can also be used with the OCRAM peripheral.

Is my understanding correct? Can broad level pointers be provided to change these applications to use the internal SRAM? Thanks.

Re: Using OCRAM as a buffer instead of SDRAM for a camera application

Yuri — Tue, 09 Jan 2018 09:05:16 GMT

Hello,

I think OCRAM size of i.MX RT1050 is not sufficient for camera applications, since, at least

double buffering scheme for storing frame buffers may be recommended in order to avoid image

tearing. It takes about 1.2 Mbytes for frame buffers to capture VGA (640 x 480) video frames with

RGB565 (two bytes) pixel format.

In real applications, ring queue structure of frame buffers may be recommended. This requires to store

several buffers in memory.

Have a great day,

Yuri

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