OMX Video capture with FB output

Danillo Graziosi

Dear all,

I am using DM8168 to capture RGB HD (1920x1080) frames. I was able to use OMAX VFCC to capture RGB, but when I tried to use frame buffer to display the content of the captured buffer, I could not map the driver address to the capture output (OMX_UseBuffer returns an error, indicating that the region of the mapped buffer is not valid).

I was still able to use the frame buffer to display the content of frame captured, however I needed to make the application copy the output buffer of the VFCC component to the mapped FB memory, which introduced a lot of latency to my solution.

Is there any way to output a captured RGB frame, HD (1920x1080) resolution using the frame buffer in real-time?

Thanks,

Danillo

over 12 years ago

0 Badri Narayanan over 12 years ago

TI__Guru 59700 points

OMX expects the buffers to be from Syslink SharedRegion so it is not possible to do use vram buffer without modifying OMX source code. If you have OMX source code you will have to add the vram memory as a SharedRegion or modify DOMX code to not use SharedRegion pointers to exchange buffer pointers. Other options are to use SGX/EDMA to copy to fbdev buffer .

0 Danillo Graziosi over 12 years ago in reply to Badri Narayanan

Intellectual 480 points

Thanks for the answer Badri. How do I use SGX/EDMA to copy to fbdev buffer? Is there any sample code I could look at ?

Thanks,

Danillo

0 Badri Narayanan over 12 years ago in reply to Danillo Graziosi

TI__Guru 59700 points

I don't know if ezSDK ships with any exampled for EDMA/SGX. You can check if these links are useful

http://processors.wiki.ti.com/index.php/TI81XX_PSP_EDMA_Driver_User_Guide has a simple edma copy example

http://processors.wiki.ti.com/index.php/GPU_Compositing explains how to display a RGB graphics plane. Not sure how useful it is for you as it is advanced case of blending video and graphics which you don't require.

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OMX Video capture with FB output