记录下,就当自己的工具了, 本来想使用ffmpeg转呢,结果命令行参数太复杂,没搞定,索性直接写吧
#include <stdio.h>
#include <stdlib.h>
/*
#include <cv.h>
#include <highgui.h>
*/
int yuv422_to_yuv420p(unsigned char *pYUV422, unsigned char *pYUV420, int width, int height)
{
int i,j;
unsigned char *pY = pYUV420;
unsigned char *pU = pYUV420 + width * height;
unsigned char *pV = pU + (width * height)/4;
unsigned char *pYUVTemp = pYUV422;
unsigned char *pYUVTempNext = pYUV422 + width * 2;
for(i = 0; i < height; i += 2) {
for(j = 0; j < width; j += 2) {
pY[j] = *pYUVTemp++;
pY[j + width] = *pYUVTempNext++;
pU[j / 2] =(*(pYUVTemp) + *(pYUVTempNext)) / 2;
pYUVTemp++;
pYUVTempNext++;
pY[j + 1] = *pYUVTemp++;
pY[j + 1 + width] = *pYUVTempNext++;
pV[j / 2] =(*(pYUVTemp) + *(pYUVTempNext)) / 2;
pYUVTemp++;
pYUVTempNext++;
}
pYUVTemp += width * 2;
pYUVTempNext += width * 2;
pY += width * 2;
pU += width / 2;
pV += width / 2;
}
return 1;
}
int main(int argc, char* argv[])
{
// char *input = "M6_897frames_422.yuv";
// char *output = "M6_897frames_420.yuv";
// int total_frames = 897;
char *input = argv[1];
char *output = argv[2];
int total_frames = atoi(argv[3]);
FILE *fp_yuv422 = fopen(input, "rb");
FILE *fp_yuv420 = fopen(output, "wb");
if (!fp_yuv422 || !fp_yuv420) {
printf("open file failed\n");
return -1;
}
int i = 0;
for (i = 0; i < total_frames; i++)
{
printf("processing frame %d\n", i);
unsigned char *yuv422_buf = (unsigned char *)malloc(2*1280*720*sizeof(unsigned char));
unsigned char *yuv420_buf = (unsigned char *)malloc(3*1280*720/2*sizeof(unsigned char));
fread(yuv422_buf, 1, 2*1280*720, fp_yuv422);
yuv422_to_yuv420p(yuv422_buf, yuv420_buf, 1280, 720);
fwrite(yuv420_buf, 1, 3*1280*720/2, fp_yuv420);
free(yuv422_buf);
free(yuv420_buf);
}
fclose(fp_yuv420);
fclose(fp_yuv422);
return 0;
}