problem using video loopback in 6748 EVM - screen flickering

Hi,

I hope this is the right place for this question

I am using the 6748 EVM (sometimes called OMAPL138 EVM) and using example code for video loopback.

The example code is from a folder called: "TMS320C6748 SOM-M1 GEL & BSL Files (CCS v4.2)"

The internal folder is : "c6748\tests\evm\cvideo" it is using the composite input and output.

The problem I get is that the screen is flickering.  that is: there is an image from the camera but something is not right - the image on the screen seems to be not in sync.

Can you please advice what to do?

Thanks !

Maoz

Here is the code attached:

uint32_t TEST_compVideo(void)
{
uint32_t rtn = ERR_NO_ERROR;

printf("------------------------------------------------------------\r\n");
printf(" C6748 Composite Video Test\r\n\r\n");

printf("Additional Equipment\r\n");
printf("--------------------\r\n");
printf("- video output device (DVD player)\r\n");
printf("- video input device (TV)\r\n");
printf("- 2 composite video cables\r\n\r\n");

printf("Test Description\r\n");
printf("----------------\r\n");
printf("connect a video output device (DVD player, etc) to\r\n");
printf("connector J6 and a video input device (TV, etc) to connector J4.\r\n");
printf("start the video output device and execute the code. The video\r\n");
printf("from the output device will be transmitted to the input device.\r\n");
printf("------------------------------------------------------------\r\n\r\n");

//------------------------------------
// initialize the required bsl modules
//------------------------------------
printf("Initialize the Required BSL Modules\r\n");
printf("-----------------------------------\r\n\r\n");

rtn = CVIDEODEC_init();
if (rtn != ERR_NO_ERROR)
{
printf("error initializing composite decoder!\r\n");
return (rtn);
}

rtn = VPIF_initReceive(VIDEO_CONN_COMPOSITE);
if (rtn != ERR_NO_ERROR)
{
printf("error initializing vpif receive composite video!\r\n");
return (rtn);
}

rtn = VPIF_initTransmit(VIDEO_CONN_COMPOSITE);
if (rtn != ERR_NO_ERROR)
{
printf("error initializing vpif transmit composite video!\r\n");
return (rtn);
}

rtn = VIDEOENC_init(VIDEO_CONN_COMPOSITE);
if (rtn != ERR_NO_ERROR)
{
printf("error initializing composite encoder!\r\n");
return (rtn);
}

rtn = LED_init();
if (rtn != ERR_NO_ERROR)
{
printf("error initializing leds!\r\n");
return (rtn);
}

//--------------
// execute test.
//--------------
printf("\r\nExecute Test\r\n");
printf("------------\r\n\r\n");

printf("toggle leds to show we are alive\r\n");
while (1)
{
LED_toggle(LED_1);
USTIMER_delay(DELAY_HALF_SEC);

LED_toggle(LED_2);
USTIMER_delay(DELAY_HALF_SEC);
}