[FAQ] PROCESSOR-SDK-DRA8X-TDA4X: How to change display resolution in vision apps?

Vision Apps by default configures display output to 1920x1080 resolution and also all demos configures the display pipeline resolution to 1920x1080. This article explains how to changes display resolution and also use it in the demo.

Display is controlled by Main R5F in vision apps. Changing resolution in display requires changes in two places, one in display controller and one in the display pipeline

• Display controller is initialized as part of the vision apps initialization ie when Main R5F firmware is loaded and appInit API is called. appInit API is implemented in the file psdk_rtos_auto_j7_07_00_00_11\vision_apps\apps\basic_demos\app_tirtos\common\app_init.c. This API fixes the output resolution and the timing parameters for the output resolution to 1080p as shown below. For new output resolution, frame size, timing parameters and pixel clock requires to be updated as per output resolution requirement. Once changed, display controller framework will take care of configuring it in the DSS.

prm.timings.width = 1920U;
prm.timings.height = 1080U;
prm.timings.hFrontPorch = 88U;
prm.timings.hBackPorch = 148U;
prm.timings.hSyncLen = 44U;
prm.timings.vFrontPorch = 4U;
prm.timings.vBackPorch = 36U;
prm.timings.vSyncLen = 5U;
prm.timings.pixelClock = 148500000ULL;

• Display pipeline is getting configured in each vision apps demo. By default, all demos use 1920x1080 as input resolution for display pipeline. For new resolution, the demo needs to be changed. For example, multi-camera example configures display pipeline resolution in API app_init_display in the file psdk_rtos_auto_j7_07_00_00_11\vision_apps\apps\basic_demos\app_multi_cam\app_display_module.c. It sets up the output resolution as 1920x1080 and position as 0x0. This API needs to be updated as per the new resolution.

Regards,
Brijesh