Zoom in Issue in the output video , using ADV7180 camera decoder, STM32f7 , 480*272 Display

[Uc.2361]

Hello ST,

I am facing Zoom in Issue of the Video.

I am using 480*272 display.   

Please help me to fix this issue. I have searched whole datasheet , but nothing found regarding the resolution.

I have adjusted the DCMI crop settings also, please point me to the solution.

I have attached the images.

fig1: Expected video resolution displayed on TV

fig2: Present output screen on the 480*272 Display which is zoomed in.

I have even posted the same issue in the ADI site

https://ez.analog.com/video/f/q-a/121188/adv7180-camera-decoder-output-video-zoom-in-issue

Thanks,

Upender.

[eng23]

Hi @Uc.2361​ ,

I'm using the ADV7182 and I would ask you about the data decoded.

I have DCMI configurated to External Synchronization, but the data received has the sync codes from ITU656 (linestart code (0x80), lineend (0x9d), framestart (0xAB) ...) so I needed to implement a decode code for this. It worked, but I spend a considerable resources from cpu to process this, when in fact the DCMI should do this. Indeed I have the YCbCr to RGB conversion by code too, so my frame rate is very low, about 4 frames/second.

Could you share/explain your DCMI setup?

Regards,

Anderson

[Uc.2361]

Hello Anderson,

please find the DCMI configuration :

DCMI_HandleTypeDef *phdcmi;

phdcmi->Init.CaptureRate   = DCMI_CR_ALTERNATE_2_FRAME ;

 phdcmi->Init.HSPolarity    = DCMI_HSPOLARITY_LOW;      

 phdcmi->Init.SynchroMode   = DCMI_SYNCHRO_HARDWARE;

 phdcmi->Init.VSPolarity    = DCMI_VSPOLARITY_HIGH;

 phdcmi->Init.ExtendedDataMode = DCMI_EXTEND_DATA_8B;

 phdcmi->Init.PCKPolarity   = DCMI_PCKPOLARITY_RISING;

 phdcmi->Instance       = DCMI;

Thanks,

Upender.

[eng23]

Hi Upender,

Well, the difference is only in the HSPolarity, I have HIGH polarity.

Do you get the raw camera data? Without the sync codes?

Do you use HAL_DCMI_FrameEventCallback() or HAL_DCMI_LineEventCallback() to trigger the camera data?

Thanks for reply,

Anderson