RGB打水印在YUV图片上

一、 概述

  将RGB图片打在YUV上需要注意的是, 字体之外应该透明, 否则背景也会被覆盖不好看,  所以RGB必须有透明度,  本测试格式为BMP ARGB8888(也即B是最低字节, A是最高字节),

YUV格式为NV21(YUV420SP), 第一步是将ARGB转换成NV21, 然后小NV21打在打NV21上即可, 最后保存图片, 用7yuv.exe软件查看!

二、 示例代码

#include <unistd.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <stdio.h>
#include <sys/ioctl.h>
#include <stdlib.h>
#include <linux/types.h>
#include <linux/videodev2.h>
#include <malloc.h>
#include <math.h>
#include <string.h>
#include <sys/mman.h>
#include <errno.h>
#include <assert.h>

#define MAX_ICON_NUM    42

#define SAVE_IMG_PATH    "./save_1280x720_nv21.yuv"
#define WATERMARK_BMP_DIR    "./watermark"

struct wm_icon
{
    int id;
    int width;
    int height;
    unsigned char *y;
    unsigned char *c;
    unsigned char *alph;
};

struct wm_icon icon_arry[MAX_ICON_NUM];

struct disp_content{
    int x;
    int y;
#define MAX_CONTENT_LEN   32
    char content[MAX_CONTENT_LEN];
};


struct backgroud_info
{
    int width;
    int height;
    unsigned char *y;
    unsigned char *c;
};

static void argb8888toyuv420sp(unsigned char *src_p, int width, int height, unsigned char *dest_y, unsigned char *dest_c, unsigned char *dest_alph)
{
    int i,j;

    for(i = 0; i < (int)height; i++) {
        if((i&1) == 0) {
            for(j= 0; j< (int)width; j++) {
                *dest_y = (299*src_p[2]+587*src_p[1]+114*src_p[0])/1000;

                if((j&1) == 0) 
                    *dest_c++ = 128+(564*(src_p[0]-*dest_y)/1000); //cb

                else
                    *dest_c++ = 128+(713*(src_p[2]-*dest_y)/1000); //cr
        

                *dest_alph++ = src_p[3];
                src_p +=4;
                dest_y++;
            }
        } else {
            for(j= 0; j< (int)width; j++) {
                *dest_y = (299*src_p[2]+587*src_p[1]+114*src_p[0])/1000;
                *dest_alph++ = src_p[3];
                src_p +=4;
                dest_y++;
            }
        }
    }

    return;
}

int init_watermark()
{
    FILE *fp = NULL;
    int i;
    int pic_width = 0, pic_height = 0;
    char filename[256];
    unsigned char *argb_buf = NULL;


    for(i = 0; i < MAX_ICON_NUM; i++) {
        sprintf(filename, "%s/argb8888_24x32_%d.bmp", WATERMARK_BMP_DIR, i);
        printf("open file %s\n", filename);
        fp = fopen(filename, "r");
        if(NULL == fp) {
            printf("Fail to open file %s(%s)!", filename, strerror(errno));
            goto OPEN_FILE_ERR;
        }
        icon_arry[i].id = i;

        /* BMP格式解析说明: https://www.cnblogs.com/vedic/p/13608566.html */
        fseek(fp, 18, SEEK_SET);
        fread(&pic_width, 1, 4, fp);
        fread(&pic_height, 1, 4, fp);
        icon_arry[i].width = abs(pic_width);
        icon_arry[i].height = abs(pic_height);
        printf("real width=%d(%d), height=%d(%d)\n", icon_arry[i].width, pic_width, icon_arry[i].height, pic_height);

        icon_arry[i].y = (unsigned char*)malloc(icon_arry[i].width * icon_arry[i].height*5/2);
        if(NULL == icon_arry[i].y) {
            printf("malloc picture yuv fail !\n");
            fclose(fp);
            goto ALLOC_Y_ERR;
        }
        memset(icon_arry[i].y, 0xff, (icon_arry[i].width * icon_arry[i].height*5/2));
        icon_arry[i].alph = icon_arry[i].y + icon_arry[i].width * icon_arry[i].height;
        icon_arry[i].c = icon_arry[i].alph + icon_arry[i].width * icon_arry[i].height;

        argb_buf = (unsigned char *)malloc(icon_arry[i].width * icon_arry[i].height * 4);
        if (NULL == argb_buf) {
            printf("malloc bmp buf fail !\n");
            fclose(fp);
            goto ALLOC_BUF_ERR;
        }

        fseek(fp, 54, SEEK_SET);
        fread(argb_buf, icon_arry[i].width * icon_arry[i].height * 4, 1, fp);

        argb8888toyuv420sp(argb_buf, icon_arry[i].width, icon_arry[i].height,
                   icon_arry[i].y, icon_arry[i].c, icon_arry[i].alph);

        fclose(fp);
        free(argb_buf);
    }

    return 0;

ALLOC_BUF_ERR:
ALLOC_Y_ERR:
OPEN_FILE_ERR:

    for(i = 0; i < MAX_ICON_NUM; ++i) {
        if(icon_arry[i].y != NULL) {
            free(icon_arry[i].y);
            icon_arry[i].y = NULL;
        }
    }
    return -1;
}

static int get_word_num(char val)
{
    int i;
    int cnt = 0;

    for(i=7; i>=0; i--) {
        if(!(val & (1<<i)))
            break;
        else
            cnt++;
    }

    if (cnt == 0)
        return 1;

    return cnt;
}

#define DEFAULT_NUM    36
static int get_word_index(char *data, int wordlen)
{
    int index = DEFAULT_NUM;

    if(wordlen == 1) {
        if (*data >= '0' && *data <= '9') {
            printf("choose numben 0 ~ 9\n");
            index = (*data - 48); //落在数组下标0开始
        } else if (*data >= 'A' && *data <= 'Z') {
            printf("choose A~Z\n");
            index = (*data - 55); //落在数组下标10开始
        } else if (*data == ' ') {
            printf("choose kong\n");
            index = 36;
        } else if (*data == '-') {
            printf("choose -\n");
            index = 37;
        } else if (*data == '.') {
            printf("choose .\n");
            index = DEFAULT_NUM;
        } else if (*data == ':') {
            printf("choose eng :\n");
            index = 38;
        } else if (*data == '/') {
            printf("choose /\n");
            index = 39;
        } else {
            printf("not match %s , use DEFAULT_NUM\n", data);
            index = DEFAULT_NUM;
        }
    } else if (wordlen == 3) {
        if(!memcmp(data, "", 3)) {
            printf("choose %s\n", "");
            index = 40;
        } else if (!memcmp(data, "", 3)) {
            printf("choose %s\n", "");
            index = 41;
        } else if (!memcmp(data, "", 3)) {
            printf("choose chn :\n");
            index = 38;
        } else {
            printf("choose DEFAULT_NUM\n");
            index = DEFAULT_NUM;
        }
    }

    printf("\twordlen -> %d, index -> %d\n", wordlen, index);
    return index;
}

void yuv420sp_blending(unsigned char *bg_y, unsigned char *bg_c, int bg_width, int bg_height, int left, unsigned int top, int fg_width, int fg_height,
                       unsigned char *fg_y, unsigned char *fg_c, unsigned char *alph)
{
    unsigned char *bg_y_p = NULL;
    unsigned char *bg_c_p = NULL;
    int i = 0;
    int j = 0;

    bg_y_p = bg_y + top * bg_width + left;
    bg_c_p = bg_c + (top >>1)*bg_width + left;

    for(i = 0; i<(int)fg_height; i++) {
        if((i&1) == 0) {
            for(j=0; j< (int)fg_width; j++) {
                *bg_y_p = ((256 - *alph)*(*bg_y_p) + (*fg_y++)*(*alph))>>8;
                *bg_c_p = ((256 - *alph)*(*bg_c_p) + (*fg_c++)*(*alph))>>8;

                alph++;
                bg_y_p++;
                bg_c_p++;
            }
            bg_c_p = bg_c_p + bg_width - fg_width;
        } else {
            for(j=0; j< (int)fg_width; j++) {
                *bg_y_p = ((256 - *alph)*(*bg_y_p) + (*fg_y++)*(*alph))>>8;
                alph++;
                bg_y_p++;
            }
        }
            bg_y_p = bg_y_p + bg_width - fg_width;
    }
}

int save_image(void *addr, int length)
{
    FILE *fp = fopen(SAVE_IMG_PATH, "w");
  
    if(fp == NULL) {
        printf("Fail to fopen %s\n", SAVE_IMG_PATH);
        exit(-1);
    }
    fwrite(addr, length, 1, fp);
    fflush(fp);
    usleep(500);
    fclose(fp);
    return 0;
}

int push_wm2bg(unsigned char *bg_yuv_buf, int bg_width, int bg_height, struct disp_content *single_wm)
{
    int pos_x;
    struct backgroud_info bg_info;
    int buflen, wordlen;
    char *p_content;
    int pic_index;
    int i;


    bg_info.width = bg_width;
    bg_info.height = bg_height;
    bg_info.y = bg_yuv_buf;
    bg_info.c = bg_yuv_buf + bg_width * bg_height;


    p_content = single_wm->content;
    buflen = strlen(single_wm->content);
    pos_x = single_wm->x;
    printf("\nshow: %s(%d Bytes):\n", p_content, buflen);
    for (i = 0; i < strlen(single_wm->content); i++) {
        wordlen = get_word_num(p_content[0]);    
        buflen -= wordlen;
        if(buflen < 0) break;
        pic_index = get_word_index(p_content, wordlen);
        

        yuv420sp_blending(bg_info.y, bg_info.c, bg_info.width, bg_info.height, pos_x, single_wm->y,
                icon_arry[pic_index].width, icon_arry[pic_index].height,
                icon_arry[pic_index].y, icon_arry[pic_index].c,
                icon_arry[pic_index].alph);

        pos_x += icon_arry[pic_index].width;
        p_content += wordlen;
    }

    return 0;
    }

/* Note:
*    input file 1280*720 NV21 format
*    watermark ARGB8888
*/
int main(int argc, char **argv)  
{
    unsigned int bg_width = 1280;
    unsigned int bg_height = 720;
    unsigned int bg_nv21_size = bg_width * bg_height * 3/2;
    FILE *fp;
    char *bg_file = argv[1];
    unsigned char *bg_yuv_buf;
    /* 汉字编码用UTF-8, 建议用UTF-8编码 */
    struct disp_content single_wm = {200, 200, "0 123456789ABC京沪:-/"};

    if(bg_file == NULL) {
        printf("Pls input backgroud file !\n");
        printf("\t eg: %s 1280x720_nv21.yuv\n", argv[0]);
        exit(-1);
    }

    fp = fopen(bg_file, "rb");
    if(fp == NULL) {
        printf("open backgroud file(%s) fail !\n", bg_file);
        exit(-1);        
    }
    
    bg_yuv_buf = (unsigned char *)malloc(bg_nv21_size);
    if(bg_yuv_buf == NULL){
        printf("malloc bg_yuv_buf fail!\n");
        exit(-1);
    }
    fread(bg_yuv_buf, 1, bg_nv21_size, fp);    

    init_watermark();
    push_wm2bg(bg_yuv_buf, bg_width, bg_height, &single_wm);
    save_image(bg_yuv_buf, bg_nv21_size);

    return 0;
}

 

fzk@mdvr:push_wm2yuv$ ./a.out 1280x720_nv21.yuv 
open file ./watermark/argb8888_24x32_0.bmp
real width=32(32), height=48(48)
open file ./watermark/argb8888_24x32_1.bmp
real width=24(24), height=32(-32)
open file ./watermark/argb8888_24x32_2.bmp
real width=24(24), height=32(-32)
open file ./watermark/argb8888_24x32_3.bmp
real width=24(24), height=32(-32)
open file ./watermark/argb8888_24x32_4.bmp
real width=24(24), height=32(-32)
open file ./watermark/argb8888_24x32_5.bmp
real width=24(24), height=32(-32)
open file ./watermark/argb8888_24x32_6.bmp
real width=24(24), height=32(-32)
open file ./watermark/argb8888_24x32_7.bmp
real width=24(24), height=32(-32)
open file ./watermark/argb8888_24x32_8.bmp
real width=24(24), height=32(-32)
open file ./watermark/argb8888_24x32_9.bmp
real width=24(24), height=32(-32)
open file ./watermark/argb8888_24x32_10.bmp
real width=24(24), height=32(-32)
open file ./watermark/argb8888_24x32_11.bmp
real width=24(24), height=32(-32)
open file ./watermark/argb8888_24x32_12.bmp
real width=24(24), height=32(-32)
open file ./watermark/argb8888_24x32_13.bmp
real width=24(24), height=32(-32)
open file ./watermark/argb8888_24x32_14.bmp
real width=24(24), height=32(-32)
open file ./watermark/argb8888_24x32_15.bmp
real width=24(24), height=32(-32)
open file ./watermark/argb8888_24x32_16.bmp
real width=24(24), height=32(-32)
open file ./watermark/argb8888_24x32_17.bmp
real width=24(24), height=32(-32)
open file ./watermark/argb8888_24x32_18.bmp
real width=24(24), height=32(-32)
open file ./watermark/argb8888_24x32_19.bmp
real width=24(24), height=32(-32)
open file ./watermark/argb8888_24x32_20.bmp
real width=24(24), height=32(-32)
open file ./watermark/argb8888_24x32_21.bmp
real width=24(24), height=32(-32)
open file ./watermark/argb8888_24x32_22.bmp
real width=24(24), height=32(-32)
open file ./watermark/argb8888_24x32_23.bmp
real width=24(24), height=32(-32)
open file ./watermark/argb8888_24x32_24.bmp
real width=24(24), height=32(-32)
open file ./watermark/argb8888_24x32_25.bmp
real width=24(24), height=32(-32)
open file ./watermark/argb8888_24x32_26.bmp
real width=24(24), height=32(-32)
open file ./watermark/argb8888_24x32_27.bmp
real width=24(24), height=32(-32)
open file ./watermark/argb8888_24x32_28.bmp
real width=24(24), height=32(-32)
open file ./watermark/argb8888_24x32_29.bmp
real width=24(24), height=32(-32)
open file ./watermark/argb8888_24x32_30.bmp
real width=24(24), height=32(-32)
open file ./watermark/argb8888_24x32_31.bmp
real width=24(24), height=32(-32)
open file ./watermark/argb8888_24x32_32.bmp
real width=24(24), height=32(-32)
open file ./watermark/argb8888_24x32_33.bmp
real width=24(24), height=32(-32)
open file ./watermark/argb8888_24x32_34.bmp
real width=24(24), height=32(-32)
open file ./watermark/argb8888_24x32_35.bmp
real width=24(24), height=32(-32)
open file ./watermark/argb8888_24x32_36.bmp
real width=24(24), height=32(-32)
open file ./watermark/argb8888_24x32_37.bmp
real width=24(24), height=32(-32)
open file ./watermark/argb8888_24x32_38.bmp
real width=24(24), height=32(-32)
open file ./watermark/argb8888_24x32_39.bmp
real width=24(24), height=32(-32)
open file ./watermark/argb8888_24x32_40.bmp
real width=24(24), height=32(32)
open file ./watermark/argb8888_24x32_41.bmp
real width=24(24), height=32(32)

show: 0 123456789ABC京沪:-/(25 Bytes):
choose numben 0 ~ 9
        wordlen -> 1, index -> 0
choose kong
        wordlen -> 1, index -> 36
choose numben 0 ~ 9
        wordlen -> 1, index -> 1
choose numben 0 ~ 9
        wordlen -> 1, index -> 2
choose numben 0 ~ 9
        wordlen -> 1, index -> 3
choose numben 0 ~ 9
        wordlen -> 1, index -> 4
choose numben 0 ~ 9
        wordlen -> 1, index -> 5
choose numben 0 ~ 9
        wordlen -> 1, index -> 6
choose numben 0 ~ 9
        wordlen -> 1, index -> 7
choose numben 0 ~ 9
        wordlen -> 1, index -> 8
choose numben 0 ~ 9
        wordlen -> 1, index -> 9
choose A~Z
        wordlen -> 1, index -> 10
choose A~Z
        wordlen -> 1, index -> 11
choose A~Z
        wordlen -> 1, index -> 12
choose 京
        wordlen -> 3, index -> 40
choose 沪
        wordlen -> 3, index -> 41
choose chn :
        wordlen -> 3, index -> 38
choose -
        wordlen -> 1, index -> 37
choose /
        wordlen -> 1, index -> 39
执行log

 

三、注意事项

  1. BMP具体解析请查看上一篇博客: https://www.cnblogs.com/vedic/p/13608566.html

  2. 请用UTF-8格式查看, 否则中文会乱码

  3. 代码自动解析BMP头部图片的宽高, 所以不只是支持32x24

  4. 黑白图片没问题, 彩色会有问题

  5. 测试用的背景图片: https://files-cdn.cnblogs.com/files/vedic/1280x720_nv21.bmp  注意将后缀改成.yuv

  6. 测试用的水印图标: https://files.cnblogs.com/files/vedic/watermark.rar

  7. 最后展示:

 

 

 

posted @ 2020-09-09 11:24  Vedic  阅读(526)  评论(0编辑  收藏  举报