Compiler/TDA2EVM5777: How can i shift the data of frame from camera sensor?

Hi Yoo,

What do you mean by shift? 

For YUV422, driver will always output frame in addr[0][0] location..

Regards,

Brijesh

Hi Brijesh,

I mean i want to move back 2bytes of data received from camera sensor.

For example, 

If the data from camera is arranged as Y U Y V Y U Y V, i want to remove the first Y U data from the buffer.

In this case, i want to access to addr of FVID2_frame.

Could you let me know whether this way is possible or acceptable?

Regards,

Yoo

Hi,

I checked from comment in source code and documentation that the data is arranged in single plane when the data format is YUV422 interleaved and progressive.

The remain thing what i to do is make the data to start from Y V not Y U.

To do this, i added this below line in CaptureLink_drvProcessData function of captureLink_drv.c .

Yoo,

it cannot be done in VIP. VIP cannot just shift 2 bytes. 

Instead of VIP doing it, can you ask sensor/decoder to drop, or shift start position?

Rgds,

Brijesh

Hi Brijesh,

Thanks for your help.

Could you tell me more about where to modify the sensor to postpone the starting point two bytes behind?

Is that part in ti_components/drivers/pdk_01_10_03_07/packages/ti/drv/vps path?

Regards,

Yoo

Yoo,

No, it depends on the sensor that you are using. If sensor supports it, you could shift in sensor. 

In VIP, you could swap the bytes, but cannot shift.

Rgds,

Brijesh

Hi Brijesh,

If i want to swap U data with V data, how could i access to data?

In VIP, there are addr element of FVID2_frame and ((System_VideoFrameBuffer*)(sysBuf->payload))->bufAddr[0].

Which one that i need to use?

Also, i really appreciate if you guide me to swap those data efficiently.

Thanks again.

Regards,

Yoo

Hi Yoo,

FVID2_Frame address is what driver uses..

If you set the output frame format to YVYU from YUYV, then chroma is swapped. 

Regards,

Brijesh

Hi Brijesh,

I wonder how the UV channel data is arranged in second plane of frame when the data format is YUV420_SP.

I tried to set some value of output frame as 0 and checked that values were changed.

At first, i thought it organized as order of U V U V U V.

However, when i swapped the value of U with value of V, the output was not changed.

The below line is what i used to set some value of frame as 0.

Hi Yoo,

Yes, for YUV420 output, chroma plane would have U followed by V and so on.

When you say, it is not working, what does it mean? You don't see bytes swapped in memory?

Is your buffer cached/ In that case, you would require to invalidate cache before updating buffer and then write back cache after updating.

Hi Brijesh,

Yes, i didn't see any bytes swapped. 

The frames that are shown in display were all same with before i apply swap the data.

I applied swap in capture link of vip_capture directory.

What i can't understand, if the cause of my problem is not invalidating/updating cache, why memset function works well...

Anyway, I'm going to try to use cache function and reply in this thread.

Thanks and Regards,

Yoo