void tskVideoLoopback() {     //设置显示的行数     numLinesDis = EVMDM642_vDisParamsChan.imgVSizeFld1;    //设置采集的行数 numLinesCap = EVMDM642_vCapParamsChan.fldYStop1 –       EVMDM642_vCapParamsChan.fldYStrt1+1;                 //取二者中较小的为程序处理的行数 numLines = (numLinesDis > numLinesCap) ? numLinesCap : numLinesDis; #ifdef _LOOPBACK //设置每行显示的像素        numPixels = EVMDM642_vCapParamsChan.fldXStop1 -            EVMDM642_vCapParamsChan.fldXStrt1+1;           //采集图像一行的总像素          capLinePitch = EVMDM642_vCapParamsChan.fldXStop1 -            EVMDM642_vCapParamsChan.fldXStrt1+1;              //显示图像一行的总像素        disLinePitch = EVMDM642_vDisParamsChan.imgHSizeFld1; #endif               numLines *= 2; /* both fields */        //分配采集和显示图像的存放缓冲区         EVMDM642_vCapParamsChan.segId = EXTERNALHEAP;         EVMDM642_vDisParamsChan.segId = EXTERNALHEAP;         EVMDM642_vDisParamsSAA7104.hI2C = EVMDM642_I2C_hI2C;         EVMDM642_vCapParamsTVP5150A.hI2C = EVMDM642_I2C_hI2C; //建立并初始化采集设备对象 #ifdef _LOOPBACK #ifdef _VP2     capChan = FVID_create("/VP2CAPTURE/A/1",             IOM_INPUT, &status, (Ptr)&EVMDM642_vCapParamsChan, NULL); #else      capChan = FVID_create("/VP0CAPTURE/A/0",             IOM_INPUT, &status, (Ptr)&EVMDM642_vCapParamsChan, NULL); #endif #endif     //建立并初始化显示设备对象     disChan = FVID_create("/VP1DISPLAY", IOM_OUTPUT,         &status, (Ptr)&EVMDM642_vDisParamsChan, NULL);     //为保证采集和显示设备正常工作，为其设置驱动     FVID_control(disChan, VPORT_CMD_EDC_BASE + EDC_CONFIG,         (Ptr)&EVMDM642_vDisParamsSAA7104); #ifdef _LOOPBACK     FVID_control(capChan, VPORT_CMD_EDC_BASE + EDC_CONFIG,         (Ptr)&EVMDM642_vCapParamsTVP5150A); #endif     //开始采集和显示操作     FVID_control(disChan, VPORT_CMD_START, NULL); #ifdef _LOOPBACK     FVID_control(capChan, VPORT_CMD_START, NULL); #endif        //分配采集和显示一帧图像存放的缓冲区     FVID_alloc(disChan, &disFrameBuf); #ifdef _LOOPBACK     FVID_alloc(capChan, &capFrameBuf); #endif     frames ++; while(1) { #ifdef _LOOPBACK         Int i;      //将采集缓冲区的内容复制到显示缓冲区中      for(i = 0; i < numLines; i ++) {           DAT_copy(capFrameBuf->frame.iFrm.y1 + i * capLinePitch,                disFrameBuf->frame.iFrm.y1 + i * disLinePitch,                numPixels);            DAT_copy(capFrameBuf->frame.iFrm.cb1 + i * (capLinePitch >> 1),                 disFrameBuf->frame.iFrm.cb1 + i * (disLinePitch >> 1),                 numPixels>>1);            DAT_copy(capFrameBuf->frame.iFrm.cr1 + i * (capLinePitch >> 1),                  disFrameBuf->frame.iFrm.cr1 + i * (disLinePitch >> 1),                  numPixels>>1);        } FVID_exchange(capChan, &capFrameBuf); #else //如果定义CAPTURE则填充图像缓冲为8条带            fillFrmBuf(&disFrameBuf->frame.iFrm, EVMDM642_vDisParamsChan.imgHSizeFld1,             EVMDM642_vDisParamsChan.imgVSizeFld1+ EVMDM642_vDisParamsChan.imgVSizeFld2, frames % 360); #endif        //将显示缓冲区中的一帧图像送给显示设备         FVID_exchange(disChan, &disFrameBuf);        //处理下一帧图像         frames ++;                 } } 产生向左平移的8条带图案： #include
#include
#include
#include    
#include "colorbar.h"      
/* static function declaration 定义每个颜 {MOD}的Y CB CR值 白黄青绿紫红蓝黑*/
static void generateColorBar(Uint8* y, Uint8* cb, Uint8* cr, Int lineSize); #define WHITE_Y        180
#define WHITE_CB       128
#define WHITE_CR       128 #define YELLOW_Y       162
#define YELLOW_CB      44
#define YELLOW_CR      142 #define CYAN_Y         131
#define CYAN_CB        156
#define CYAN_CR        44 #define GREEN_Y        112
#define GREEN_CB       72
#define GREEN_CR       58 #define MAGENTA_Y       84
#define MAGENTA_CB     184
#define MAGENTA_CR     198 #define RED_Y          65
#define RED_CB         100
#define RED_CR         212 #define BLUE_Y          35
#define BLUE_CB        212
#define BLUE_CR        114 #define BLACK_Y        16
#define BLACK_CB       129
#define BLACK_CR       129 /* defines arrays to hold a line of image for color bar generating */
#pragma DATA_ALIGN(imgLineY, 8);
#pragma DATA_ALIGN(imgLineCb, 8);
#pragma DATA_ALIGN(imgLineCr, 8); static Uint8 imgLineY[1920 * 3];
static Uint8 imgLineCb[960 * 3];
static Uint8 imgLineCr[960 * 3]; /*
 * ======== fillFrmBuf ========
 * This function fill a frame with color bar of Y/Cb/Cr format.
 */ void fillFrmBuf(FVID_IFrame* frame, Int lineSz, Int numLines, Int offset )
{
    Int i;
    static Int init = 0;
    Int id;
    if(!init) {
        generateColorBar(imgLineY, imgLineCb, imgLineCr, lineSz);
        CACHE_clean(CACHE_L2ALL, NULL, NULL);
        init = 1;
    }    
    for(i = 0; i < numLines; i ++) {        
        DAT_copy(imgLineY + offset * 2, frame->y1 + lineSz * i, lineSz);
        DAT_copy(imgLineCb + offset, frame->cb1 + (lineSz >> 1) * i, 
            (lineSz >> 1));
        id = DAT_copy(imgLineCr + offset, frame->cr1+(lineSz >> 1) * i, 
            (lineSz >> 1));
    }             
    DAT_wait(id);         
}          /*
 * ======== generateColorBar ========
 * This function generates a line of color bar with y/cb/cr format.
 */ static void generateColorBar(Uint8* y, Uint8* cb, Uint8* cr, Int lineSize)
{
    Int i;   
    Int fillSize = lineSize >> 3;
    Int k;
    
    if(fillSize & 0x1) {
        fillSize ++;
    }
    /* white bar */
    for(k = 0; k < 3; k ++) {
        for(i = 0; i<(fillSize >> 1); i++) {             y[2 * i] = WHITE_Y;
            y[2 * i + 1] = WHITE_Y;
            cb[i] = WHITE_CR;
            cr[i] = WHITE_CB;             y[fillSize * 1 + 2 * i] = YELLOW_Y;
            y[fillSize * 1 + 2 * i + 1] = YELLOW_Y;
            cb[(fillSize >> 1) * 1 + i] = YELLOW_CB;
            cr[(fillSize >> 1) * 1 + i] = YELLOW_CR;             y[fillSize * 2 + 2 * i] = CYAN_Y;
            y[fillSize * 2 + 2 * i + 1] = CYAN_Y;
            cb[(fillSize >> 1) * 2 + i] = CYAN_CB;
            cr[(fillSize >> 1) * 2 + i] = CYAN_CR;             y[fillSize * 3 + 2 * i] = GREEN_Y;
            y[fillSize * 3 + 2 * i + 1] = GREEN_Y;
            cb[(fillSize >> 1) * 3 + i] = GREEN_CB;
            cr[(fillSize >> 1) * 3 + i] = GREEN_CR;
            y[fillSize * 4 + 2 * i] = MAGENTA_Y;
            y[fillSize * 4 + 2 * i + 1] = MAGENTA_Y;
            cb[(fillSize >> 1) * 4 + i] = MAGENTA_CB;
            cr[(fillSize >> 1) * 4 + i] = MAGENTA_CR;             y[fillSize * 5 + 2 * i] = RED_Y;
            y[fillSize * 5 + 2 * i + 1] = RED_Y;
            cb[(fillSize >> 1) * 5 + i] = RED_CB;
            cr[(fillSize >> 1) * 5 + i] = RED_CR;
 
            y[fillSize * 6 + 2 * i] = BLUE_Y;
            y[fillSize * 6 + 2 * i + 1] = BLUE_Y;
            cb[(fillSize >> 1) * 6 + i] = BLUE_CB;
            cr[(fillSize >> 1) * 6 + i] = BLUE_CR;               y[fillSize * 7 + 2 * i] = BLACK_Y;
            y[fillSize * 7 + 2 * i + 1] = BLACK_Y;
            cb[(fillSize >> 1) * 7 + i] = BLACK_CB;
            cr[(fillSize >> 1) * 7 + i] = BLACK_CR;
        }    
        y  += lineSize;
        cb += lineSize >> 1;
        cr += lineSize >> 1;
    } }