用c语言实现3个yuv420图片拼接

由于没有具体的需求描述，以下是一种实现方式：

读取三张YUV420格式的图片，并分别分离出Y、U、V三个分量。
分别计算出三张图片的宽度和高度。
根据三张图片的宽度和高度，创建一个新的YUV420格式的图片。
将三张图片的Y分量依次拷贝到新的图片的Y分量中。
将三张图片的U分量和V分量分别拷贝到新的图片的U分量和V分量中，注意需要根据UV分量的宽度和高度进行拷贝。
将新的图片保存到磁盘中。

下面是一个简单的示例代码：

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#define WIDTH 640
#define HEIGHT 480

int main(int argc, char *argv[])
{
    if (argc != 4) {
        fprintf(stderr, "Usage: %s <input1.yuv> <input2.yuv> <input3.yuv>\n", argv[0]);
        return -1;
    }

    FILE *fp1 = fopen(argv[1], "rb");
    FILE *fp2 = fopen(argv[2], "rb");
    FILE *fp3 = fopen(argv[3], "rb");

    if (!fp1 || !fp2 || !fp3) {
        fprintf(stderr, "Failed to open input file.\n");
        return -1;
    }

    unsigned char *y1 = (unsigned char *)malloc(WIDTH * HEIGHT);
    unsigned char *u1 = (unsigned char *)malloc(WIDTH * HEIGHT / 4);
    unsigned char *v1 = (unsigned char *)malloc(WIDTH * HEIGHT / 4);

    unsigned char *y2 = (unsigned char *)malloc(WIDTH * HEIGHT);
    unsigned char *u2 = (unsigned char *)malloc(WIDTH * HEIGHT / 4);
    unsigned char *v2 = (unsigned char *)malloc(WIDTH * HEIGHT / 4);

    unsigned char *y3 = (unsigned char *)malloc(WIDTH * HEIGHT);
    unsigned char *u3 = (unsigned char *)malloc(WIDTH * HEIGHT / 4);
    unsigned char *v3 = (unsigned char *)malloc(WIDTH * HEIGHT / 4);

    unsigned char *y = (unsigned char *)malloc(WIDTH * HEIGHT * 3 / 2);
    unsigned char *u = y + WIDTH * HEIGHT;
    unsigned char *v = u + WIDTH * HEIGHT / 4;

    fread(y1, 1, WIDTH * HEIGHT, fp1);
    fread(u1, 1, WIDTH * HEIGHT / 4, fp1);
    fread(v1, 1, WIDTH * HEIGHT / 4, fp1);

    fread(y2, 1, WIDTH * HEIGHT, fp2);
    fread(u2, 1, WIDTH * HEIGHT / 4, fp2);
    fread(v2, 1, WIDTH * HEIGHT / 4, fp2);

    fread(y3, 1, WIDTH * HEIGHT, fp3);
    fread(u3, 1, WIDTH * HEIGHT / 4, fp3);
    fread(v3, 1, WIDTH * HEIGHT / 4, fp3);

    fclose(fp1);
    fclose(fp2);
    fclose(fp3);

    memcpy(y, y1, WIDTH * HEIGHT);
    memcpy(y + WIDTH * HEIGHT, y2, WIDTH * HEIGHT);
    memcpy(y + WIDTH * HEIGHT * 2, y3, WIDTH * HEIGHT);

    memcpy(u, u1, WIDTH * HEIGHT / 4);
    memcpy(u + WIDTH * HEIGHT / 4, u2, WIDTH * HEIGHT / 4);
    memcpy(u + WIDTH * HEIGHT / 2, u3, WIDTH * HEIGHT / 4);

    memcpy(v, v1, WIDTH * HEIGHT / 4);
    memcpy(v + WIDTH * HEIGHT / 4, v2, WIDTH * HEIGHT / 4);
    memcpy(v + WIDTH * HEIGHT / 2, v3, WIDTH * HEIGHT / 4);

    FILE *fp_out = fopen("output.yuv", "wb");
    fwrite(y, 1, WIDTH * HEIGHT * 3 / 2, fp_out);
    fclose(fp_out);

    free(y1);
    free(u1);
    free(v1);
    free(y2);
    free(u2);
    free(v2);
    free(y3);
    free(u3);
    free(v3);
    free(y);

    return 0;
}